模拟失重对大鼠血浆ghrelin、VIP和胃肠动力的影响

目的探讨模拟失重状态下胃肠激素ghrelin和VIP的改变以及对胃肠动力的影响。方法 32只Wistar大鼠,随机分为4组,每组8只,按模拟失重的时程分为14 d组和21 d组,并分别设立非悬吊14 d对照组和非悬吊21 d对照组。先后进行胃浆膜肌电的描记、葡聚糖蓝2000标记法测定胃残留率和小肠推进率,血浆ghrelin和VIP浓度分别用酶免法(ELISA)和放免法(RI)测定。结果悬吊14 d组与21 d组与相应对照组比较,ghrelin浓度下降VIP浓度升高,同时表现为胃肌电延缓,胃残留率增加;小肠推进率下降,差异均具有统计学意义(P<0.05)。结论模拟失重状态下血浆ghrelin下降和VIP升高可能是导致胃肠动力下降的重要因素之一。

The effects of simulated weightlessness on plasma ghrelin,plasma VIP and gastrointestinal motility

Objective To investigate the effects of simulated weightless on the gut hormones(ghrelin and VIP) and gastrointestinal motility. Methods According to the different courses of tail-suspension,thirty two Wistar rats were randomly devided into 4 groups: 14-day tail-suspension(SUS-14 d) and 14-day control groups(CON-14 d),21-day tail-suspension(SUS-21 d) and 21-day control groups(CON-21 d)(n=8/group).Gastromyoelectrical activity of the rat sinus ventriculi was recorded.Then gastric residual rate and intestinal propulsive ratio were measured by BD2000.Plasma concentrations of ghrelin and VIP were determined by an enzymatic spectrophotometric assay and radioimmunoassay respectively. Results Plasma concentrations of ghrelin decreased and VIP increased in the SUS-14d and SUS-21 d compared with the control groups.At the same time,gastromyoelectrical activity was delayed,gastric residual rates increased,and intestinal propulsive ratios decreased in the SUS-14 d and SUS-21 d compared with the control groups.The differences were significant(P<0.05). Conclusion Simulated weightlessness results in down-regulation of plasma ghrelin and up-regulation of plasma VIP.The changes of these gut hormones are proposed to weaken the gastrointestinal motility in the tail-suspension model rats.