四种胃肠激素在糖尿病胃动力障碍中的作用

Effects of neuroendocrine peptides on gastric dysmotility in diabetic mellitus

目的通过对糖尿病大鼠模型离体胃窦平滑肌自发性收缩运动的研究,探讨血浆和胃窦组织中生长抑素(SS),血管活性肠肽(VIP),胃动素(MTL),P物质(SP)等在糖尿病胃动力障碍中的作用。方法建立糖尿病大鼠模型,制备实验组和对照组大鼠离体胃窦环行肌及纵行肌肌条,应用张力换能器测定其静息张力、平均振幅、收缩频率等运动指标;用放免法同批测定两组大鼠血浆和胃窦组织中SS,VIP,MTL和SP含量。结果①糖尿病组胃窦肌条自发收缩运动的多项指标均较对照组明显降低(P<0.01);②糖尿病组血浆中SS、VIP、MTL增加,SP降低;胃窦组织中SS增加,MTL和SP降低,VIP无变化;③血浆和胃组织SS与胃运动指标呈负相关;血浆VIP与MTL与胃运动指标呈负相关;血浆和胃组织SP和胃运动指标无明显相关性。结论①糖尿病多伴有胃运动功能障碍;②血浆和胃组织中胃肠激素含量变化在糖尿病胃动力障碍的发病中有一定作用。

Objective To investigate the relationship between contractive activity of isolated gastric antrum smooth muscle and the change of somatostatin(ss), vasoactive intestinal peptide (VIP), motilin(MTL), substance P (SP) in diabetic mellitus rats. Methods Twenty male Sprague-Dawley rats were divided into two groups: the control(n=10) and the experimental(n=10). The resting tension, the mean contractile amplitude and frequency of spontaneous changes of isolated longitudinal, circular gastric antrum smooth muscle strips were measured by transducer, and SS, VIP, MTL, SP levels in plasma and gastric antrum tissue extracts were measured by radioimmunoassay. Results In isolated gastric antrum smooth muscle strips, the motility parameters were significantly decreased in diabetic rats than those in control(P<0.01). In diabetic rats, the plasma levels of SS, VIP and MTL were higher than those in control(P<0.01, P<0.05), while SP level was decreased(P<0.05). In the gastric antrum, the level of SS was significantly higher than in the controls (P<0.01). The levels of SP and MTL were lower than those of the controls (P<0.05, P<0.01). The level of VIP did not differ from that in the controls (P>0.05). In diabetic rats, there were negative correlations between the plasma, tissue SS levels and the motility parameters of gastric antrum strips, and the plasma VIP and MTL had negative correlations with the motility parameters of gastric antrum strips, but the VIP and MTL level of gastric tissue had no correlation with strip motility parameters. The plasma and tissue SP level had no excellent correlation with gastric strip motility parameters. Conclusion Diabetic rats have gastrointestinal dysfunction and it is related with the disturbed neuroendocrine peptides. The changes of these peptides' levels in plasma and gastric tissue may play some roles in the gastric motility disorders of diabetes mellitus.