褪黑素在鸡脊柱侧凸模型中的影响

目的　通过鸡松果体蒂部切断的方法 ,研究褪黑素在松果体切除鸡脊柱侧凸动物模型中的作用。方法　 10只刚孵育出的WhiteLeghorn鸡作为对照组 ,未行任何处理 ,控制白天 12h光照 (强度 5 0 0Lux)、夜间 12h完全黑暗 (强度 0 - 5lux)条件下饲养 ;2 0只WhiteLeghorn鸡在鸡龄 3d时行松果体切除 ,控制光照条件同对照组 ;2 0只WhiteLeghorn鸡 3d时行松果体蒂部切断术 ,控制光照同对照组。 5周时留取所有鸡白天 (mid -day)和夜间 (mid -night)的血清 ,用RIA试剂盒测定血清中褪黑素含量。所有的鸡处死后 ,取骨骼标本 ,行脊柱前后位平片检查。结果　 5周时 ,对照组褪黑素含量呈现明显白天低 (5 7.2 5± 7.4 3)pg/ml,夜间高 (2 5 7.92± 2 6 .0 9)pg/ml的周期性变化。松果体切除组褪黑素含量 ,白天为 (6 0 .0 5± 5 .4 8)pg/ml,夜间为 (5 5 .0 9± 8.35 )pg/ml,其分泌维持低水平。松果体蒂部切断组褪黑素含量 ,白天为 (5 8.77± 8.4 4 )pg/ml,夜间为 (2 4 8.4 7± 2 7.2 1)pg/ml,仍呈白天低 ,夜间高的周期性变化。X线检查 :对照组 10只鸡无脊柱侧凸发生 ;松果体切除组 2 0只鸡中 9只鸡发生了脊柱侧凸 ,发生率为 4 5 % ;松果体蒂部切断组 2 0只鸡中有 11只发生了侧弯 ,发生率为 5 5 %。结论　松果体切除和松果体蒂部

Effect of Melatonin in Pathogenesis of Chicken' s Scoliosis

Objective To find the role of melatonin in the pathogenesis of chicken's scoliosis via excision of pineal stalk. Methods 10 white Leghorn chicken in the control group were kept in light-dark (12h:12h) cycle, 500 Lux in day-time and 0~5 Lux in night-time after birth. Pinealectomy was performed in 20 white Leghorn chicken when 3-day-old and then kept in light-dark cycle as the control group. Pineal stalks were excised in 20 chicken when 3-day-old. At 5 weeks, mid-day and mid-night blood samples were taken in all chicken and assaied for melatonin using RIA kit. X-films of AP view were performed on all chicken spine for confirming scoliosis after the skeleton specimens were obtained. Results At 5 weeks, the level of melatonin in control group was low in day-time (57.24±7.43)pg/ml and high in night-time (257.92±26.09)pg/ml. It was very low level, day-time (60.05±5.48)pg/ml,and night-time (55.09±8.35)pg/ml in pinealectomy group. The level of melatonin in the stalk excision group was low in day-time (58.77±8.44)pg/ml and high in night-time (248.47±27.21)pg/ml. When the chicken had X-ray examination, there was no scoliosis in the control group. There were 9 chicken (45%) with scoliosis in the pinealectomized group and 11 chicken (55%) with scoliosis in stalk excised group. Conclusion Both of pinealectomy and stalk excised can induce scoliosis in chicken. Although melatonin remain the normal secretion in the stalk excised group, scoliosis can be induced by excision of stalk. The pathogenesis of chicken scoliosis is not induced via low-level melatonin.