持续光照与松果体切除诱导大鼠脊柱侧凸动物模型的探讨  

Comparison of melatonin suppression on experimental scoliosis in rats by either constant light or surgical pinealectomy

作　　者：张网林[1] 陈秋[2] 

机构地区：[1]复旦大学附属儿科医院小儿外科,上海市200032 [2]宁波市第六医院,浙江省315000

出　　处：《临床小儿外科杂志》2008年第2期18-21,共4页Journal of Clinical Pediatric Surgery

摘　　要：目的应用持续光照以及松果体切除来抑制大鼠褪黑素水平,探讨单纯褪黑素降低在大鼠脊柱侧凸模型中的作用。方法取生后3周的青春期(Sprague Dawley,SD)大鼠50只,随机分为4组。空白对照组10只,自然光照条件;二足对照组10只,双侧前肢及尾巴切断,自然光照条件;实验光照组20只,双侧前肢及尾巴切断,24h持续光照,照度控制在300lux;松果体切除组10只,双侧前肢及尾巴切断,手术切除松果体,自然光照条件。实验至第12周时,进行脊柱X线摄片,观察脊柱曲线,测量Cobb角,留取动物2Am及2Pm静脉血,测定血清褪黑素含量。结果(1)实验至第12周时,空白对照组、二足对照组以及实验光照组X线摄片均无脊柱侧凸的发生。松果体切除组中有3只出现脊柱侧凸,发生率为33.3%,Cobb角为14°,21°和28°,平均21°。侧凸主弧方向为右侧2只,左侧1只。(2)空白对照组及二足对照组血清褪黑素水平呈现明显昼低夜高的节律性。实验光照组血清褪黑素呈现持续低水平且节律性消失。松果体切除组褪黑素水平改变与光照组类似。经统计学检验,空白对照组与二足对照组组内昼夜血清褪黑素水平明显不同,实验光照组与松果体切除组组间昼夜血清褪黑素水平比较,差异无统计学意义;空白对照组与二足对照组的夜间褪黑素水平与实验光照组及松果体切除组差异显著。结论(1)持续光照能够有效地抑制大鼠血清褪黑素水平,并使其丧失原有的节律性。(2)二足鼠松果体切除能够建立脊柱侧凸的动物模型。(3)该模型中侧凸的发生不是单纯低水平褪黑素的作用。Objective To compare the effect of suppression of melatonin secretion by constant light in bipedal rats with that of surgical pinealectomy. And to discover whether suppression of melatonin secretion without surgery can result in scoliosis in mammals. Methods Fifty rats were separated into four groups： a quadrupedal control group （n=10） with no surgery performed; a bipedal control group （n=10） served as another contral; a pinealectomy group（n=10） and a constant light group （n=20）. The first three group were kept together in a 12-hour light-dark cycle,whereas the last group was separated with constant lighting conditions（〉300lux）. The last three groups were made bipedal rats by surgery. All rats were radiographed at the end of the experiment. Blood was taken during the middle of the light and dark cycles for serum melatonin assay using ELISA. Results Thirty-three percent of the pinealectomized bipedal rats suffered from scoliosis. None of the other three groups had scoliosis developed for up to 12 weeks. Measurements of serum melatonin levels of the constant light group confirm that secretion is suppressed. Conclusions Pinealectomy can reduce the secretion of melatonin and induce scoliosis in bipedal rats, Constant light could suppress the secretion of melatonin in rats serum, it did not induce scoliosis. The pathogenesis of rat＇s seoliosis might not be mediated by low-level melatonin.

关 键 词：脊柱侧凸 大鼠 血清褪黑素 临床分析 

分 类 号：R682[医药卫生—骨科学] R-332[医药卫生—外科学]