模拟失重对大鼠动脉血胃动素和一氧化氮的影响

Influence of Simulated Weightlessness on Arterial Blood Motilin and Nitric Oxide in Rats

背景：随着载人航天事业的迅速发展，对失重状态下身体各器官系统变化的研究越来越受到重视。目前，关于失重状态下胃肠激素变化的研究尚少。目的：研究模拟失重状态下大鼠动脉血中胃动素和一氧化氮的变化，初步探讨两者在失重状态下胃肠功能调控中的可能作用。方法：90只雄性Wistar大鼠随机分为三组，每组各30只。第一组悬吊14d（SUS-14d组），第二组悬吊21d（SUS．21d组），第三组（对照组）不予悬吊。腹主动脉采血，测定动脉血胃动素（放射免疫法）和一氧化氮（硝酸还原酶法）水平。结果：模拟失重状态下（SUS-14d组和SUS．21d组），大鼠动脉血胃动素水平较对照组明显升高，差异有统计学意义（P〈O．05）；一氧化氮水平与对照组相比差异无统计学意义（P〉O．05）。结论：模拟失重状态下，大鼠动脉血胃动素水平明显升高，一氧化氮水平变化不明显。胃动素水平的变化可能与失重状态下发生的胃肠功能改变有关，其具体机制有待进一步研究。

Background： Since the rapid development of manned space program, much attention has been paid on the studies of changes of organs and systems during weightlessness status. So far, there are few studies focused on the changes of gastrointestinal hormones. Aims： To investigate the changes of arterial blood motilin （MTL） and nitric oxide （NO） in rats under simulated weightlessness, and to explore their possible roles in regulating the digestive function under weightlessness. Methods： Ninety male Wistar rats were divided randomly into three groups, each with 30 rats, Rats in the first group were suspended by tail for 14 days （SUS-14 d）, those in the second group were suspended for 21 days （SUS-21 d）, and rats in the third group were set as the control group. Blood samples were obtained from abdominal aorta, MTL concentration was measured by radioimmunoassay, and NO concentration by nitrate reductase method. Results： Compared with normal rats, arterial blood MTL was much higher in rats under simulated weightlessness （SUS-14 d group and SUS-21 d group） （P〈0.05）, while the NO concentration was not significantly different among these groups （PM）.05）. Conclusions： MTL concentration in arterial blood is significantly increased in rats under simulated weightlessness, whereas NO has no significant change. The change of MTL concentration may be correlated with the change of digestive function during weightlessness status, but its precise mechanism remains to be studied.