急性游泳运动对链脲佐菌素诱导糖尿病大鼠血瘦素及下丘脑瘦素受体表达影响的免疫组织化学实验

Immunohistochemical experiment on the effect of acute swimming on blood leptin level and leptin-receptor expression in hypothalamus of rats with diabetes

目的:观察急性游泳运动对链脲佐菌素诱导的糖尿病大鼠血瘦素及下丘脑瘦素受体表达的影响。方法:实验于2003-09/2004-01在河北师范大学生命科学学院生理实验室完成。①选用雄性SD大鼠56只,单纯随机分为正常组(n=8)和模型组(n=48),模型组又分为非运动组、运动后即刻组、运动后1,3,6和12h组,每组8只。②模型组大鼠腹腔注射链脲佐菌素60mg/kg复制糖尿病大鼠模型,正常组大鼠腹腔注射等体积柠檬酸缓冲液。③运动后即刻组、运动后1,3,6和12h组进行一次性60min游泳运动,尾部负重3%体质量;正常组和非运动组浸水后捞出。④运动后不同时刻取血测定血糖、血胰岛素、血瘦素,取脑做免疫组化冰冻切片,观察下丘脑瘦素受体表达的积分吸光度。结果:56只大鼠全部进入结果分析。①血糖:模型组大鼠显著高于正常组(P<0.05)。②血清胰岛素水平:模型组大鼠显著低于正常组(P<0.05),运动后1h组血胰岛素值最低,比非运动组低了22.14%,运动后12h组与非运动组比较差异不显著(P>0.05)。③血清瘦素浓度:模型组大鼠显著低于正常组(P<0.05),运动后即刻组低于非运动组[(0.81±0.06),(1.38±0.07)μg/L,P<0.05],运动后1,3,6和12h组则显著高于运动后即刻组(P<0.05)。④胰岛素敏感指数:模型组大鼠显著低于正常组(P<0.05),运动后3,6h高于非运动组(P<0.05),运动后6h甚至超过了正常组的水平,较正常组高26.53%。⑤下丘脑瘦素受体表达的积分吸光度:模型组大鼠显著低于正常组(P<0.05);运动后即刻组较非运动组高21.89%,运动后1,3,6,12h较非运动组高32.84%,61.19%,48.26%,16.42%。结论:①一次性游泳运动可以降低糖尿病大鼠血胰岛素、血瘦素水平。②一次性游泳运动能够提高大鼠下丘脑瘦素受体的表达,运动可能促进血瘦素向下丘脑转运。③一次性游泳运动对糖尿病大鼠血瘦素、胰岛素敏感指数、下丘脑瘦素受体的影响有时相性特点。

AIM： To investigate the effect of acute swimming on letpin and expression of leptin-reeeptor in hypothalamus of diabetic rats induced by streptozotocin （STZ）. METHODS： The experiment was conducted in the Physiological Laboratory of College of Life Science, Hebei Normal University between September 2003 and January 2004.（1）Fifty-six male MD rats were selected and randomly divided into normal group （n=8） and model group （n=48）. The model group was subdivided into non-exercise group, immediate post- exercise group as well as 1, 3, 6, and 12 hours after exercise group with 8 rats in each group. （2）Rats in the model group were abdominally injected with 60 mg/kg STZ to establish rat models of diabetes, while rats in the normal group were abdominally injected with same-volume of citrate buffer solution.（3）Rats in the immediate post-exercise group, 1, 3, 6, 12 hours after exercise groups were required to swim for 60 minutes with a tail load weighting 3% of the body mass. Rats in the normal group and group were taken out of the water. （4）The blood samples were collected at different time-point after exercise to detect the blood sugar, insulin and leptin by immunohistochemical assay, and the integral absorbance in the expression of leptin-receptor in hypothalamus was studied. RESULTS： A total of 56 rats were involved in the analysis of results.（1） Level of blood glucose： it was obviously higher in the model group than the normal group （P 〈 0.05）. （2）The level of plasma insulin was the lowest at one hour after exercise, which was 22.14% lower than the non-exercise group, while there were no significant after excise group and the non-exercise differences between the 12-hour （P 〈 0.05）. （3）Coneentration of plasma leptin： it was remarkably lower in the model group than the normal group （P 〈 0.05）, and it was lower in the immediate post-exercise group than the non-exercise group [（0.81±0.06）,（1.38±0.07） μg/L,P〈 0.05], while it was significantly higher in 1-hour, 3-hour, 6-hour and 12-hour after exercise groups （P 〈 0.05）. （4）Insulin sensitivity index （ISI）： it was markedly lower in the model group than the normal group （P 〈 0.05）, and was higher in 3-hour, 6-hour after exercise groups than the non-exercise group （P 〈 0.05）. The 1SI in the 6-hour after exercise group was even higher than that in the normal group, which was 26.53% higher than the normal group. （5）The integral absorbance of leptin receptor expression in hypothalamus： it was significantly lower in the model group than the normal group （P 〈 0.05）, and that in the immediate post-exercise group was 21.89% higher than the non-exercise group. Those in one-hour, 3-hour, 6- hour, and 12-hour after exercise groups were 32.84% ,61.19%,48.26% and 16.42% respectively higher than the non-exercise group. CONCLUSION： （1）Acute aerobic exercise can down-regulate the levels of plasma insulin and leptin in rats with diabetes. （2）Acute aerobic exercise can up-regulate the expression of leptin-reeeptor in hypothalamus of rats, and exercise may promote the transportation of leptin from blood to cerebrospinal fluid.（3）The effect of acute aerobic exercise on leptin, ISI and leptin-reeeptor of hypotbalamus in rats with diabetes is characteristics of phase.