Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

Effect of thyroid hormone level on the expression of synaptotagmin Ⅰ in adult rat hippocampus

Objective To observe the effect of different thyroid hormone level on the expression of synaptotagmin Ⅰ(Syt Ⅰ) in adult rat hippocampus. Methods All 28 adult male SD rats were assigned randomly into hypothyroid, hyperthyroid and control group, hypothyroid group was established by daily intraperitoneal injections with propylthiou raci(PTU, 10.0 mg/kg body weight) for 6 weeks and hyperthyroid group with L-Thyroxine (L-T4, 0.5 mg/kg body weight) for 3 weeks. Radioimmunity method was used to assay the levels of serum T3 and T4, immunohistochemical S-P technology to assay the levels of Syt Ⅰ protein in hippoeampus CA1, CA3 and dentate gyrus (DG). The layers analyzed in the different subfields include the polymorphic cell layer(the stratum oriens, SO), pyramidal cell layer(PCL), stratum radiatum (SR), lacunosum-molecular layer (SLM) in CA1 and CA3, granular cell layer(GL) and molecular layer(ML) in DG. Results The levels of serum T3 and T4[(0.34±0.12), (41.03± 11.37)nmol/L]in the hypothyroid rats were significantly lower than those in the control group[(0.65±0.15), (55.20±10.68)nmol/L, P < 0.01 or < 0.05], and the positive granule of Syt Ⅰ was significantly lower in PCL and SR of CA1 and CA3, GL of DG. The average optical value responsible for Syt Ⅰ immunoreactivity was obviously reduced in SO(0.048±0.007), PCL(0.299±0.035), SR(0.042±0.007), SLM(0.038±0.006) of CA1, PCL(0.085± 0.019), SR(0.040±0.011), SLM (0.038±0.006) of CA3, GL (0.076±0.019) of DG than normal controls (0.068± 0.014, 0.376±0.053, 0.053±0.008,0.056±0.009,0.118±0.026,0.052±0.010,0.053±0.009,0.099±0.015; P< 0.01 or < 0.05). Serum T3 and T4 levels [(1.43±0.30), (157.18±19.95)nmol/L]of hyperthyroid rats were significantly higher than those of control group(P < 0.01). The value was reduced in PCL(0.322±0.050), SR(0.039±0.006), SLM (0.042±0.006) of CA1, PCL(0.098±0.034), SR(0.046±0.013), SLM(0.046±0.010) of CA3 and GL(0.085± 0.024), ML (0.042±0.009) of DG (P < 0.05 or < 0.01). Conclusion Adult-onset of hypothyroidism and hyperthyroidism can reversibly decrease the expression of Syt Ⅰ in CA1, CA3 and DG regions of hippocampus.     

成年期甲状腺功能减退症大鼠额叶突触结合蛋白I表达及T4替代治疗作用

Objective To observe the expression of synaptotagmin I(syt I)protein in the prefrontal cortex of adult-onset hypothyroidism rats and the effects of replicated therapy in different doses of thyroid hormone on the syt I protein.Methods All 44 aduh male Sprague-Dawley rats were divided into 4 groups randomly according to their body mass:hypothyroidism group,routine dosage thyroxine treatment group,high dosage thyroxine treatment group and control group.The adult male Sprague-Dawley rats were replicated to the adult-onset hypothyroidism and treatment models with propyhhiouracil(PTU).The levels of serum T3,T4 were assayed by the radioimmunoassay method and the level of the syt I protein in the molecular layer,external granular layer,external pyramidal layer,internal granular layer and internal pyramidal layer in prefrontal cortex was analyzed by immunohistochemistry.Results In the hypothyroidism group,the levels of serum T3 and T4[(0.34±0.04),(43.01±2.95)nmol/L]were significantly lower than those in the control group[(0.65±0.15), (55.20±3.56)nmol/L, F value: 6.026,5.940,4.503,P<0.05 or <0.01 ], the levels of the syt I protein in the molecular layer(0.018±0.010), external granular layer (0.020±0.007), external pyramidal layer(0.013±0.008), internal granular layer(0.011±0.005), internal pyramidal layer(0.024±0.013) of prefrontal lobe were significantly lower compared to the control group[(0.028±0.010,0.031 ± 0.010,0.028 ± 0.010,0.022 ± 0.008,0.038 ± 0.013), F value: 5.697,8.965,14.668,13.597,6.807,P<0.05 or <0.01 ]. In the routine dosage of the thyroxine treatment group, the levels of serum T3,T4 [(0.63 ±0.05), (55.04 ± 3.77)nmol/L] were not significantly different compared to the control group(F value: 3.162,0.367,all P>0.05), and the level of the syt I protein in the molecular layer, external granular layer, external pyramidal layer, internal granular layer and internal pyramidal layer in prefrontal cortex showed a significant improvement of the syt I protein(0.027 ± 0.013,0.025 ± 0.009,0.022 ± 0.008,0.020 ± 0.010,0.033 ± 0.010), which were similar to that of the control group(F value: 0.094,2.208,2.467,0.350,0.693, all P>0.05). In the high dosage thyroxine thyroid hormone treatment group, the levels of serum T3 and T4[ (1.11 ± 0.10), (96.68 ± 6.42)nmoL/L] were higher than the control group(F value: 6.291,12.031, all P<0.01), the expression of the syt I protein(0.028 ± 0.008,0.031 ±0.011,0.026 ± 0.012,0.023 ± 0.011,0.038 ± 0.010) were not significantly different compare to the control group (F value: 0.001,0.019,0.111,0.061,0.001, all P>0.05). Conclusions The expression of the syt I protein in the prefrontal cortex of adult-onset hypothyroidism can be decreased, which can be reversed by routine dosage of thyroxine treatment.     

成年期甲状腺功能减退症大鼠额叶突触结合蛋白I表达及T4替代治疗作用

Objective To observe the expression of synaptotagmin I(syt I)protein in the prefrontal cortex of adult-onset hypothyroidism rats and the effects of replicated therapy in different doses of thyroid hormone on the syt I protein.Methods All 44 aduh male Sprague-Dawley rats were divided into 4 groups randomly according to their body mass:hypothyroidism group,routine dosage thyroxine treatment group,high dosage thyroxine treatment group and control group.The adult male Sprague-Dawley rats were replicated to the adult-onset hypothyroidism and treatment models with propyhhiouracil(PTU).The levels of serum T3,T4 were assayed by the radioimmunoassay method and the level of the syt I protein in the molecular layer,external granular layer,external pyramidal layer,internal granular layer and internal pyramidal layer in prefrontal cortex was analyzed by immunohistochemistry.Results In the hypothyroidism group,the levels of serum T3 and T4[(0.34±0.04),(43.01±2.95)nmol/L]were significantly lower than those in the control group[(0.65±0.15), (55.20±3.56)nmol/L, F value: 6.026,5.940,4.503,P<0.05 or <0.01 ], the levels of the syt I protein in the molecular layer(0.018±0.010), external granular layer (0.020±0.007), external pyramidal layer(0.013±0.008), internal granular layer(0.011±0.005), internal pyramidal layer(0.024±0.013) of prefrontal lobe were significantly lower compared to the control group[(0.028±0.010,0.031 ± 0.010,0.028 ± 0.010,0.022 ± 0.008,0.038 ± 0.013), F value: 5.697,8.965,14.668,13.597,6.807,P<0.05 or <0.01 ]. In the routine dosage of the thyroxine treatment group, the levels of serum T3,T4 [(0.63 ±0.05), (55.04 ± 3.77)nmol/L] were not significantly different compared to the control group(F value: 3.162,0.367,all P>0.05), and the level of the syt I protein in the molecular layer, external granular layer, external pyramidal layer, internal granular layer and internal pyramidal layer in prefrontal cortex showed a significant improvement of the syt I protein(0.027 ± 0.013,0.025 ± 0.009,0.022 ± 0.008,0.020 ± 0.010,0.033 ± 0.010), which were similar to that of the control group(F value: 0.094,2.208,2.467,0.350,0.693, all P>0.05). In the high dosage thyroxine thyroid hormone treatment group, the levels of serum T3 and T4[ (1.11 ± 0.10), (96.68 ± 6.42)nmoL/L] were higher than the control group(F value: 6.291,12.031, all P<0.01), the expression of the syt I protein(0.028 ± 0.008,0.031 ±0.011,0.026 ± 0.012,0.023 ± 0.011,0.038 ± 0.010) were not significantly different compare to the control group (F value: 0.001,0.019,0.111,0.061,0.001, all P>0.05). Conclusions The expression of the syt I protein in the prefrontal cortex of adult-onset hypothyroidism can be decreased, which can be reversed by routine dosage of thyroxine treatment.     

Effects of different levels of iodine concentration on insulin-like growth factors Ⅰ mRNA expression of thyroid and breast in lactating rats

Objective To study the effects of different levels of iodine concentration on insulin-like growth factors Ⅰ (IGF-1) mRNA expression of thyroid and breast in lactating rats. Methods Thirty Wistar female rats, having been weaned for 1 month, were randomly divided into three groups according to their body weights, i. e. :low iodine(LI) group,adequate iodine(AI) group, high iodine(HI) group, 10 rats in each group. Synthetic fodder and deionized water containing iodine of 0,150,3000 μg/L was respectively fed to these rats. After fed for 3 months, the rats mated and had offspring. Their mammary glands, thyroids and serum were sampled at lactation day 5. The serum iodine of lactating rats were determined by moderate acid digestion method, level of T3 and T4 were determined by radioimmunoassay method, and the expressions of IGF-1 mRNA of mammary glands and thyroids were determined by real-time fluorescence quantitative PCR assay. Results The value of serum iodine of LI group [(17.38±3.27) μg/L] was lower than that of AI group [(43.42±6.92) μg/L, P<0.05], and the value of serum iodine of HI group[(350.10±38.46)μg/L] was higher than that of AI group (P<0.05). The level of T3 of LI group and HI group[ (1.11±0.25), (1.61±0.33)μg/L] reduced obviously compared with that of AI group[(2.18±0.46) μg/L, P<0.05]. The mean of T4 of LI group and HI group[(33.40±11.11),(56.54±10.38)μg/L] had no statistical significance compared with AI group(44.02±12.51)μg/L, P>0.05), but the level of T4 of LI group was lower than that of HI group(P<0.05). The level of IGF-1 mRNA expression of thyroid in LI group and HI group (0.34±0.08, 0.23±0.08) was higher than that of AI group(0.15±0.03, P<0.05). The level of IGF-1 mRNA expression of lactating mammary in LI group(0.59±0.18) was higher than that of AI group(0.40±0.10, P<0.05). The level of IGF-1 mRNA expression of thyroid was lower than that of breast between the same group(t=3.54, 6.44,2.62, all P<0.05). Conclusion Iodine could affect IGF-1 mRNA expression of thyroid and lactating mammary, and IGF-1 mRNA expression of lactating mammary was stronger than that of the thyroid.     

The effects of angiotensin Ⅱ on the synthesis of albumin and type Ⅰ collagen in human hepatic cells

Objective To investigate the effects of angiotensin Ⅱ (AngⅡ) on the expression of albumin and the synthesis of type Ⅰ collagen in human normal hepatic cells. Methods HL-7702 cells (human normal hepatocyte) were cultured and divided into control group, Ang Ⅱ treated group, an AngⅡ+irbesartan (co-stimulated) group. The expressions of albumin and type Ⅰ collagen were detected by immunofluorescence and Western blotting, respectively. The mRNA level of type Ⅰ collagen was measured by real time-PCR(qRT-PCR). Results After stimulated with 10-7 mol/L Ang Ⅱ for 72 hours, the expression of albumin significantly decreased in Ang Ⅱ treated group compared with control group (0.85±0.11 vs 1. 41±0.23,P=0.000), while the mRNA expression increased in AngⅡ treated group compared with control group (1.00±0.08 vs 3.72±0.19,P=0.000). In costimulated group, however, the expression of albumin significantly increased (0.85 ± 0.11 vs 1.38 ±0.32,P=0.000),and mRNA expression (3. 72±0.19 vs 2.86±0.13,P=0.000) and synthesis of type Ⅰ collagen were reduced when compared with Ang Ⅱ treated group. Conclusions The reduction of albumin and elevated systhesis of type Ⅰ collagen in HL-7702 cells are induced via Ang Ⅱ AT1 receptor.     

The effects of angiotensin Ⅱ on the synthesis of albumin and type Ⅰ collagen in human hepatic cells

Objective To investigate the effects of angiotensin Ⅱ (AngⅡ) on the expression of albumin and the synthesis of type Ⅰ collagen in human normal hepatic cells. Methods HL-7702 cells (human normal hepatocyte) were cultured and divided into control group, Ang Ⅱ treated group, an AngⅡ+irbesartan (co-stimulated) group. The expressions of albumin and type Ⅰ collagen were detected by immunofluorescence and Western blotting, respectively. The mRNA level of type Ⅰ collagen was measured by real time-PCR(qRT-PCR). Results After stimulated with 10-7 mol/L Ang Ⅱ for 72 hours, the expression of albumin significantly decreased in Ang Ⅱ treated group compared with control group (0.85±0.11 vs 1. 41±0.23,P=0.000), while the mRNA expression increased in AngⅡ treated group compared with control group (1.00±0.08 vs 3.72±0.19,P=0.000). In costimulated group, however, the expression of albumin significantly increased (0.85 ± 0.11 vs 1.38 ±0.32,P=0.000),and mRNA expression (3. 72±0.19 vs 2.86±0.13,P=0.000) and synthesis of type Ⅰ collagen were reduced when compared with Ang Ⅱ treated group. Conclusions The reduction of albumin and elevated systhesis of type Ⅰ collagen in HL-7702 cells are induced via Ang Ⅱ AT1 receptor.     

Effect of tumor necrosis factor-α with different levels of iodine on expression of Na+/I- symporter in cultured lactating mammary cells

Objective To observe the expression of Na+/I- symporter(NIS) in cultured lactating mammary cells with different levels of iodine and the effect of tumor necrosis factor-α(TNF-α). Methods Original generation of mouse lactating mammary cells cultured in vitro were divided into low iodine group Ⅰ (LI-Ⅰ), low iodine group Ⅱ (LI-Ⅱ), adequate iodine group(AI), high iodine group Ⅰ(HI-Ⅰ), and high iodine group Ⅱ(HI-Ⅱ). Cells were cultured in DEME/F12 culture medium for 24 h with different concentrations of iodine (0,5,50,3000 and 10 000 μg/L, respectively), and TNF-α( 10-2 mg/L) was added to some of cultured cells for 24 h. The expression of NIS mRNA of lactating mammary cells was determined by real-time quantitative PCR and the expression of NIS protein was detected by In-Cell Western. Results In iodine alone group, the expression of NIS mRNA in LI-Ⅰ group [ (64.66 ± 14.99) x 10-4] was higher than that of AI group[ (22.76 ± 7.36) × 10-4, P ＜ 0.01 ]; HI-I group[ (10.18 ±3.53) × 10-4] and HI-Ⅱ group[ (8.59 ± 2.89) × 10-4] were lower than that of AI group(all P ＜ .0.05); With increased iodine concentration, the expression of NIS mRNA decreased. The expression of NIS mRNA in LI-Ⅰ group [(2.72 ± 0.45) × 10-4], LI-Ⅱ group[ (2.69 ± 0.68) × 10-4] and AI group[(1.80 ± 0.67) × 10-4] with iodine plus TNF-o were all lower than that of LI-Ⅰ group, LI-Ⅱ group[ (29.82 ± 4.47 ) × 10-4], and AI group without TNF-α (all P ＜ 0.01). In iodine plus TNF-α, the expression of NIS mRNA in HI-Ⅰ group[(6.58 ± 2.87) × 10-4] and HI-Ⅱ[(7.04 ± 1.36) × 10-4] group were all higher than that of AI group(all P ＜ 0.05); With increased iodine deficiency or iodine excess, the expression of NIS mRNA increased. With increased iodine concentration, the expression of NIS protein decreased in iodine alone group. The expression of NIS protein in iodine plus TNF-α was all lower than that in iodine alone group. In iodine plus TNF-α, the expression of NIS protein increased in both iodine deficiency and iodine excess conditions. Conclusions Iodine may decrease the expression of NIS mRNA and protein of lactating mammary cells. The expression of NIS mRNA and protein of lactating mammary cells was inhibited by TNF-α under different levels of iodine.     

碘/钠摄入量对小鼠血脂代谢影响的实验研究

Objective The present study has been designed to investigate the impact of dietary iodine/sodium intake on blood lipid metabolism in mice. Methods According to body weight and gender, two hundred and sixty Balb/c mice were randomly divided into 2 groups including normal sodium group(Na) and low sodium group(LNa), with 130 animals per group. Each group were then randomly further divided into 5 sub-groups according to the amount of iodine intake: ① severe iodine deficiency(SID); ② mild iodine deficiency(MID); (③normal iodine (NI); ④ 10-fold high iodine ( 10HI ); (⑤ 50-fold high iodine (50HI), 10 groups in total, 26 per group.Eight months later, the body weight and the levels of urinary iodine, thyroid hormones and total cholesterol (TC),Results In Na group, the levels of TG and TC in male mice of SID group[ (1.64 ± 0.35), (3.88 ± 0.35 )mmol/L]and MID group[ ( 1.67 ± 0.31 ), (3.41 ± 0.66)mmol/L] were significantly higher than that of NI group[ ( 1.49 ± 0.42), (3.25 ± 0.47)mmol/L] and the levels of TG in female mice of SID group[(1.52 ± 0.22)mmol/L] were significantly higher than that of NI group[ (1.23 ± 0.22)mmol/L]. In addition, the levels of TG in male mice of 10HI and 50HI groups [ ( 1.16 ± 0.23 ), ( 1.21 ± 0.27 ) mmol/L ] were significantly lower than that of NI group [ ( 1.49 ± 0.42)mmol/L, all P ＜ 0.05], the levels of TC in female mice of 10HI and 50HI groups[(2.37 ± 0.49), (2.48 ± 0.37)mmol/L] were significantly lower than that of NI group[ (2.84 ± 0.37) mmol/L, all P ＜ 0.05 ]. In LNa group,the levels of TG and TC in male mice of SID group[ (1.39 ± 0.40), (3.33 ± 0.46 )mmol/L] were significantly lower than that of NI group [(1.30 ± 0.28), (3.00 ± 0.53) mmol/L, all P ＜ 0.05], the levels of TG, TC and LDL in female mice of SID group[ (1.48 ± 0.26), (2.76 ± 0.43), (0.62 ± 0.22)mmol/L], the levels of LDL in female mice of MID group[ (0.60 ± 0.17 )mmol/L] were significantly lower than that of NI group[(l.22 ± 0.36), (2.51 ± 0.38),(0.48 ± 0.08), (0.48 ± 0.08)mmol/L, all P ＜ 0.05], the levels of TG in male mice of 10HI and 50HI group [ (1.12 ± 0.22), (0.90 ± 0.11 )mmol/L] were significantly lower than that of NI group (all P ＜ 0.05 ), the levels of TC in female mice of 10HI and 50HI groups[ (2.35 ± 0.34), (2.37 ± 0.37)mmol/L], the levels of LDL in female mice of 50HI group[(0.65 ± 0.18)mmol/L], were significantly lower than that of NI group(all P ＜ 0.05). In Na group, the levels of thyroid hormones were distinctively decreased in SID group[TT4(0.00 ± 0.00)nmol/L, FT4 (0.93 ± 0.42)pmol/L, TT3(0.49 ± 0.07)nmol/L, FT3(2.86 ± 0.37)pmol/L] and MID group [TT4 (17.15 ± 15.26)nmol/L, FT4( 18.46 ± 4.31 )pmol/L, TT3(0.67 ± 0. 10)nmol/L, FT3(3.18 ± 0.24)pmol/L] compared with that of the NI group [TT4 (37.15 ± 15.26)nmol/L, FT4(28.46 ± 4.31)pmol/L, TT3(0.85 ± 0.10)pmol/L, FT3(3.87 ± 0.24)pmol/L, all P ＜ 0.05 ]. In LNa group, the levels of thyroid hormones were distinctively decreased in SID group [TT4 (0.00 ± 0.00) nmol/L,FT4(1.03 ± 0.78)pmol/L, TT3(0.51 ± 0.05)nmol/L, FT3(3.01 ± 0.17)pmol/L] and MID group[TT4(19.76 ± 12.22)nmol/L, FT4(21.46 ± 5.37)pmol/L, TT3(0.71 ± 0.21)nmol/L, FT3(3.56 ± 0.23)pmol/L] compared with that of the NI group[TT4(36.23 ± 14.72)nmol/L, FT4(30.96 ± 6.33)pmol/L, TT3(0.89 ± 0.20)nmol/L, FT3(4.05 ± 0.24)pmol/L, all P ＜ 0.05]. Conclusions Dietary iodine intake plays an important role in the blood lipid metabolism. Iodine deficiency could increase while iodine excess could decrease the levels of serum TG, TC or LDL in mice. Monitoring the amount of iodine intake during sodium restriction should have an important role in effective prevention and treatment of cardiovascular disease.     

碘缺乏和甲状腺功能减退对大鼠仔鼠小脑细胞外信号调节激酶1/2蛋白表达的影响

Objective To study the effects of iodine deficiency and hypothyroidism on protein expression of extracellular signal-regulate kinase(ERK1/2) in the cerebellum of rots. Methods Twenty-eight healthy Wistar rots, female, 60 days old, were randomly divided according to their body weight into control group, iodine deficient group and hypothyroidism groups. Hypothyroidism groups in accordance with drinking water containing propylthiouracil(PTU) were divided into doses of 5 mg/L and 15 mg/L groups, 7 rats in each group. Rats after pregnancy, iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water. Pup's cerebellum in each group were weighed on day 14,21,28 and 42. Cerebellum tissue was observed for cerebellar morphology using silver staining and detected for ERK1/2 protein using immunohistochemistry on day 7,14,21,28 and 42. Results On day 14,21,28 and 42, cerebellum weight of pups from iodine-deficient[(0.0945±0.0233), (0.1347±0.0046), (0.1542±0.0094), (0.1949±0.0048)g]were significantly lighter than control[(0.1856±0.0123), (0.2049±0.0098), (0.2268±0.0065), (0.2606±0.0086)g, all P < 0.05]and hypothyroidism groups [for 5 mg/L group: (0.1741±0.0172), (0.1927±0.0103), (0.2181±0.0064), (0.2583±0.0054)g, all P<0.05; for 15 mg/L group: (0.1604±0.0083), (0.1682±0.0103), (0.1996±0.0073) and (0.2579±0.0067)g, all P< 0.05]the difference had statistical significance(F=6.325,8.870, 16.191 and 21.574, all P<0.05). Compared to the controls on day 7, iodine-deficient group didn't have clear layers; on day 21, disappearance of external granule cells from iodine-deficient and 15 mg/L groups was delayed, still two or three layer external granule cells remained; on day 28 and 42, molecular layer from 5, 15 mg/L and iodine-deficient groups and became thinner. Immunohistochemistry showed that on day 7, there was no statistical difference of integrated optical density average of ERK1/2, in all the groups(F=1.102, P>0.05); on day 14,21,28 and 42, integrated optical density average of ERK1/2 in iodine-deficient group[(7.3245±0.5070), (8.3606±1.0683), (9.1217±1.0402), (12.1587±0.7581), all P<0.01]and hypothyroidism groups [for 5 mg/L group: (11.4307±1.5200), (14.919±0.8497), (16.0082±1.1130), (15.7721±0.8293), all P< 0.01; for 15 mg/L group: (7.8538±0.9775), (11.2461±0.8138),(12.78±1.3783), (13.0871±1.1450), all P < 0.01]was significantly lower than those of controls [(16.2831±0.5143), (20.2653±0.9551), (22.7485±1.0267), (22.1725±0.9939), all P < 0.01], the difference having a statistical signifieance(F=16.131,13.543,26.953,41.583, all P<0.01). Conclusions Iodine deficiency and hypothyroidism during critical periods of brain development may change eerebellar morphology and down regulate the protein expression of ERK1/2, which may result in damage of cerebellum development.     

碘缺乏和甲状腺功能减退对大鼠仔鼠小脑细胞外信号调节激酶1/2蛋白表达的影响

Objective To study the effects of iodine deficiency and hypothyroidism on protein expression of extracellular signal-regulate kinase(ERK1/2) in the cerebellum of rots. Methods Twenty-eight healthy Wistar rots, female, 60 days old, were randomly divided according to their body weight into control group, iodine deficient group and hypothyroidism groups. Hypothyroidism groups in accordance with drinking water containing propylthiouracil(PTU) were divided into doses of 5 mg/L and 15 mg/L groups, 7 rats in each group. Rats after pregnancy, iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water. Pup's cerebellum in each group were weighed on day 14,21,28 and 42. Cerebellum tissue was observed for cerebellar morphology using silver staining and detected for ERK1/2 protein using immunohistochemistry on day 7,14,21,28 and 42. Results On day 14,21,28 and 42, cerebellum weight of pups from iodine-deficient[(0.0945±0.0233), (0.1347±0.0046), (0.1542±0.0094), (0.1949±0.0048)g]were significantly lighter than control[(0.1856±0.0123), (0.2049±0.0098), (0.2268±0.0065), (0.2606±0.0086)g, all P < 0.05]and hypothyroidism groups [for 5 mg/L group: (0.1741±0.0172), (0.1927±0.0103), (0.2181±0.0064), (0.2583±0.0054)g, all P<0.05; for 15 mg/L group: (0.1604±0.0083), (0.1682±0.0103), (0.1996±0.0073) and (0.2579±0.0067)g, all P< 0.05]the difference had statistical significance(F=6.325,8.870, 16.191 and 21.574, all P<0.05). Compared to the controls on day 7, iodine-deficient group didn't have clear layers; on day 21, disappearance of external granule cells from iodine-deficient and 15 mg/L groups was delayed, still two or three layer external granule cells remained; on day 28 and 42, molecular layer from 5, 15 mg/L and iodine-deficient groups and became thinner. Immunohistochemistry showed that on day 7, there was no statistical difference of integrated optical density average of ERK1/2, in all the groups(F=1.102, P>0.05); on day 14,21,28 and 42, integrated optical density average of ERK1/2 in iodine-deficient group[(7.3245±0.5070), (8.3606±1.0683), (9.1217±1.0402), (12.1587±0.7581), all P<0.01]and hypothyroidism groups [for 5 mg/L group: (11.4307±1.5200), (14.919±0.8497), (16.0082±1.1130), (15.7721±0.8293), all P< 0.01; for 15 mg/L group: (7.8538±0.9775), (11.2461±0.8138),(12.78±1.3783), (13.0871±1.1450), all P < 0.01]was significantly lower than those of controls [(16.2831±0.5143), (20.2653±0.9551), (22.7485±1.0267), (22.1725±0.9939), all P < 0.01], the difference having a statistical signifieance(F=16.131,13.543,26.953,41.583, all P<0.01). Conclusions Iodine deficiency and hypothyroidism during critical periods of brain development may change eerebellar morphology and down regulate the protein expression of ERK1/2, which may result in damage of cerebellum development.     

碘缺乏和甲状腺功能减退对大鼠仔鼠小脑细胞外信号调节激酶1/2蛋白表达的影响

Objective To study the effects of iodine deficiency and hypothyroidism on protein expression of extracellular signal-regulate kinase(ERK1/2) in the cerebellum of rots. Methods Twenty-eight healthy Wistar rots, female, 60 days old, were randomly divided according to their body weight into control group, iodine deficient group and hypothyroidism groups. Hypothyroidism groups in accordance with drinking water containing propylthiouracil(PTU) were divided into doses of 5 mg/L and 15 mg/L groups, 7 rats in each group. Rats after pregnancy, iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water. Pup's cerebellum in each group were weighed on day 14,21,28 and 42. Cerebellum tissue was observed for cerebellar morphology using silver staining and detected for ERK1/2 protein using immunohistochemistry on day 7,14,21,28 and 42. Results On day 14,21,28 and 42, cerebellum weight of pups from iodine-deficient[(0.0945±0.0233), (0.1347±0.0046), (0.1542±0.0094), (0.1949±0.0048)g]were significantly lighter than control[(0.1856±0.0123), (0.2049±0.0098), (0.2268±0.0065), (0.2606±0.0086)g, all P < 0.05]and hypothyroidism groups [for 5 mg/L group: (0.1741±0.0172), (0.1927±0.0103), (0.2181±0.0064), (0.2583±0.0054)g, all P<0.05; for 15 mg/L group: (0.1604±0.0083), (0.1682±0.0103), (0.1996±0.0073) and (0.2579±0.0067)g, all P< 0.05]the difference had statistical significance(F=6.325,8.870, 16.191 and 21.574, all P<0.05). Compared to the controls on day 7, iodine-deficient group didn't have clear layers; on day 21, disappearance of external granule cells from iodine-deficient and 15 mg/L groups was delayed, still two or three layer external granule cells remained; on day 28 and 42, molecular layer from 5, 15 mg/L and iodine-deficient groups and became thinner. Immunohistochemistry showed that on day 7, there was no statistical difference of integrated optical density average of ERK1/2, in all the groups(F=1.102, P>0.05); on day 14,21,28 and 42, integrated optical density average of ERK1/2 in iodine-deficient group[(7.3245±0.5070), (8.3606±1.0683), (9.1217±1.0402), (12.1587±0.7581), all P<0.01]and hypothyroidism groups [for 5 mg/L group: (11.4307±1.5200), (14.919±0.8497), (16.0082±1.1130), (15.7721±0.8293), all P< 0.01; for 15 mg/L group: (7.8538±0.9775), (11.2461±0.8138),(12.78±1.3783), (13.0871±1.1450), all P < 0.01]was significantly lower than those of controls [(16.2831±0.5143), (20.2653±0.9551), (22.7485±1.0267), (22.1725±0.9939), all P < 0.01], the difference having a statistical signifieance(F=16.131,13.543,26.953,41.583, all P<0.01). Conclusions Iodine deficiency and hypothyroidism during critical periods of brain development may change eerebellar morphology and down regulate the protein expression of ERK1/2, which may result in damage of cerebellum development.     

碘缺乏和甲状腺功能减退对大鼠仔鼠小脑细胞外信号调节激酶1/2蛋白表达的影响

Objective To study the effects of iodine deficiency and hypothyroidism on protein expression of extracellular signal-regulate kinase(ERK1/2) in the cerebellum of rots. Methods Twenty-eight healthy Wistar rots, female, 60 days old, were randomly divided according to their body weight into control group, iodine deficient group and hypothyroidism groups. Hypothyroidism groups in accordance with drinking water containing propylthiouracil(PTU) were divided into doses of 5 mg/L and 15 mg/L groups, 7 rats in each group. Rats after pregnancy, iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water. Pup's cerebellum in each group were weighed on day 14,21,28 and 42. Cerebellum tissue was observed for cerebellar morphology using silver staining and detected for ERK1/2 protein using immunohistochemistry on day 7,14,21,28 and 42. Results On day 14,21,28 and 42, cerebellum weight of pups from iodine-deficient[(0.0945±0.0233), (0.1347±0.0046), (0.1542±0.0094), (0.1949±0.0048)g]were significantly lighter than control[(0.1856±0.0123), (0.2049±0.0098), (0.2268±0.0065), (0.2606±0.0086)g, all P < 0.05]and hypothyroidism groups [for 5 mg/L group: (0.1741±0.0172), (0.1927±0.0103), (0.2181±0.0064), (0.2583±0.0054)g, all P<0.05; for 15 mg/L group: (0.1604±0.0083), (0.1682±0.0103), (0.1996±0.0073) and (0.2579±0.0067)g, all P< 0.05]the difference had statistical significance(F=6.325,8.870, 16.191 and 21.574, all P<0.05). Compared to the controls on day 7, iodine-deficient group didn't have clear layers; on day 21, disappearance of external granule cells from iodine-deficient and 15 mg/L groups was delayed, still two or three layer external granule cells remained; on day 28 and 42, molecular layer from 5, 15 mg/L and iodine-deficient groups and became thinner. Immunohistochemistry showed that on day 7, there was no statistical difference of integrated optical density average of ERK1/2, in all the groups(F=1.102, P>0.05); on day 14,21,28 and 42, integrated optical density average of ERK1/2 in iodine-deficient group[(7.3245±0.5070), (8.3606±1.0683), (9.1217±1.0402), (12.1587±0.7581), all P<0.01]and hypothyroidism groups [for 5 mg/L group: (11.4307±1.5200), (14.919±0.8497), (16.0082±1.1130), (15.7721±0.8293), all P< 0.01; for 15 mg/L group: (7.8538±0.9775), (11.2461±0.8138),(12.78±1.3783), (13.0871±1.1450), all P < 0.01]was significantly lower than those of controls [(16.2831±0.5143), (20.2653±0.9551), (22.7485±1.0267), (22.1725±0.9939), all P < 0.01], the difference having a statistical signifieance(F=16.131,13.543,26.953,41.583, all P<0.01). Conclusions Iodine deficiency and hypothyroidism during critical periods of brain development may change eerebellar morphology and down regulate the protein expression of ERK1/2, which may result in damage of cerebellum development.