脑室内注射瘦素对大鼠胃肠运动的影响

Intracerebroventricular injection of leptin inhibits gastric emptying but has no effect on intestinal transit in rats

目的:观察脑室内注射瘦素对大鼠胃肠运动的影响.方法:♀SD大鼠52只(180-220g),将大鼠随机分为对照组和瘦素干预组,根据干预的时间再分为1、3、5h3个亚组.实验前1wk行侧脑室置管,在无麻醉状态下每只老鼠从侧脑室注射瘦素3.5g/L,对照组注射等量生理盐水.大鼠(n=28,每组n=7)处死前15min以500mg/L的酚红溶液2mL灌胃,取出整个鼠胃,以蒸馏水冲洗胃内容物,定容为20mL,加入20mL 0.5mol/L NaOH搅拌混匀,取上清液以分光光度计于560nm波长处测定吸光度值,计算胃排空率.大鼠(n=24,每组n=6)处死前15min给予5%炭粉混悬液灌胃,计算无张力下小肠推进指数.结果:瘦素给药1、3、5h胃排空率低于对照组,差异有统计学意义(54.7%±8.3%,54.6%±9.3%,57.4%±8.9% vs 70.0%±6.1%,均P<0.05).瘦素给药各亚组之间相比,差异无统计学意义.瘦素1、3、5h小肠推进率分别为41.1%±4.9%、49.5%±13.6%、43.6%±5.5%,与对照组(43.0%±6.3%)相比,差异无统计学意义.结论:给大鼠侧脑室微量注射瘦素抑制了大鼠的胃排空,对大鼠的小肠推进率却没有影响.

AIM：To investigate whether injection of leptin into the lateral cerebral ventricle has impact on gastrointestinal motility in rats.METHODS：Fifty-two female Sprague-Dawley rats were randomly divided into two groups：normal control group and leptin group.The leptin group was further divided into three subgroups for detection at 1,3,and 5 h.For intracerebroventricular infusion,a guide cannula was fixed into the lateral cerebral ventricle one week before the experiment.Under no anesthesia,leptin（3.5 g/L） was injected into the lateral cerebral ventricle through the implanted guide cannula.Equal volume of saline was injected as a control.After the injection,rats were subjected to measurement of the rate of gastric emptying and the rate of intestinal transit.RESULTS：The rate of gastric emptying decreased more signif icantly in the three leptin subgroups than in the normal control group（54.7% ± 8.3%,54.6% ± 9.3%,57.4% ± 8.9% vs 70.0% ± 6.1%,all P〈 0.05）.However,there is no signif icant difference in the rate of intestinal transit between the leptin subgroups and normal control group（41.1% ± 4.9%,49.5% ± 13.6%,43.6% ± 5.5% vs 43.0% ± 6.3%,all P〉 0.05）.CONCLUSION：Intracerebroventricular injection of leptin inhibits gastric emptying but has no effect on intestinal transit in rats.