锌缺乏对大鼠骨骼矿化的影响

目的　探讨缺锌对大鼠骨骼矿化的影响。方法　将 30只Wistar大鼠按体重随机分为缺锌组、对照组和对喂组 ,每组 10只。缺锌组饲料锌含量为 3 9mg/kg ,对照组饲料锌含量为 2 4 7mg/kg,对喂组饲对照组饲料 ,饲料摄入量与缺锌组相同。运用骨组织形态计量学方法测量骨骼矿化相关指标、测定股骨矿物质含量、骨密度、骨中锌、钙、磷、镁、锰、铜元素和骨骼羟脯氨酸含量及血中甲状旁腺激素、降钙素和骨钙素含量。结果　缺锌组大鼠与对照组和对喂组相比 ,骨矿化沉积速率、股骨磷、锌、骨羟脯氨酸及血清降钙素、骨钙素含量显著降低 ,缺锌组相应指标分别为 :( 3 2 6± 0 34) μm/d、( 6 4 5 4± 2 34)g/kg、( 5 4 4± 9 5 )mg/kg、( 9 2 8± 1 6 2 )g/kg、( 41 2± 13 5 ) μg/L、( 82± 30 ) μg/L ;对照组分别为 :( 5 37± 0 5 3) μm/d、( 6 9 0 1± 4 0 5 )g/kg、( 117 4± 8 0 )mg/kg、( 11 31± 1 30 )g/kg、( 6 8 3± 14 4)μg/L、( 131± 46 ) μg/L ;对喂组分别为 :( 5 45± 0 30 ) μm/d、( 6 7 81± 3 5 6 )g/kg、( 10 6 7± 8 4)mg/kg、( 10 88± 1 47)g/kg、( 6 3 7± 12 0 ) μg/L、( 12 0± 5 2 ) μg/L。骨矿化延迟时间和骨基质成熟时间显著增加 ,缺锌组相应指标分别为 :( 1 0 8± 0 19)

Effects of zinc deficiency on bone mineralization and its mechanism in rats

OBJECTIVE: To study the influence of zinc deficiency on bone mineralization. METHODS: Thirty Wistar rats were randomly divided into three groups with ten in each group, i.e., zinc-deficient group (ZD), control group, and pair-fed group. Histomorphological changes of bone mineralization, bone mineral content and bone density, bone contents of zinc, calcium, phosphorus, magnesium, manganese, copper and hydroxyproline, and serum levels of parathyroid hormone, calcitonin and osteocalcin in the rats were measured. RESULTS: The results showed that the mineral deposit rate and bone contents of zinc, phosphorus and hydroxyproline, and serum levels of calcitonin and osteocalcin lowered significantly in ZD group, as compared with those in the control and pair-fed groups, with (3.26 +/- 0.34) micro m/d, (64.54 +/- 2.34) g/kg, (54.4 +/- 9.5) mg/kg, (9.28 +/- 1.62) g/kg, (41.2 +/- 13.5) micro g/L, (82 +/- 30) micro g/L in ZD group; (5.37 +/- 0.53) micro m/d, (69.01 +/- 4.05) g/kg, (117.4 +/- 8.0) mg/kg, (11.31 +/- 1.30) g/kg, (68.3 +/- 14.4) micro g/L, (131 +/- 46) micro g/L in the control group; and (5.45 +/- 0.30) micro m/d, (67.81 +/- 3.56) g/kg, (106.7 +/- 8.4) mg/kg, (10.88 +/- 1.47) g/kg, (63.7 +/- 12.0) micro g/L, (120 +/- 52) micro g/L in the pair-fed group, respectively. While the time for mineralization lag and osteoid maturation obviously prolonged, (1.08 +/- 0.19) d and (7.12 +/- 2.30) d in ZD group, (0.39 +/- 0.06) d and (2.21 +/- 1.12) d in the control group, and (0.40 +/- 0.06) d and (2.12 +/- 0.58) d in the pair-fed group, respectively. In addition, bone mineral content and bone density and serum parathyroid hormone in ZD group decreased significantly and were lower than those in the control group, but not significantly different from those in the pair-fed group. There were no significant difference in femoral contents of calcium, magnesium, manganese and copper between the ZD group and the control and pair-fed groups. CONCLUSIONS: Zinc deficiency could lower the contents of parathyroid hormone and calcitonin in blood circulation affecting bone mineral deposit and causing defect in bone mineralization.