断流术中迷走神经切断对肝硬变门脉高压大鼠胃粘膜的影响

THE EFFECT OF VAGOTOMY IN DEVASC- ULARINATION ON THE GASTRIC MUCOSA IN RATS WITH EXPERIMENTAL CIRRHOTIC PORTAL HYPERTENSION

术后再出血率高是断流术的主要缺点,究其原因,胃粘膜损害起到重要作用。为了探索其发生机制,以求改善断流术疗效,本实验观察了实验性肝硬变门脉高压时以及联合断流术,尤其是迷走神经切断后大鼠胃粘膜防御性及致伤性因素的变化。结果发现:肝硬变门脉高压时大鼠胃粘膜血流量及胃结合粘液量明显低于正常(P<0.05),而基础胃液量、胃酸分泌量、及胃蛋白酶活性无明显变化;单纯血行阻断术后,胃粘膜血流量、胃结合粘液量、胃酸分泌量及酸浓度明显低于非手术组,而联合断流术(迷切)后进一步降低;各组胃蛋白酶活性均无明显变化。术后动态观察发现,迷切后近期胃酸分泌量有恢复趋势。本研究结果进一步说明了肝硬变门脉高压时胃粘膜损害的主要原因是胃粘膜防御机制的削弱;断流术、尤其是其中的迷切,进一步降低了胃粘膜血流量及结合粘液量,使本已脆弱的胃粘膜防御机制更加削弱,从而促进了胃粘膜损伤。因此我们认为有必要对迷切在断流术中的价值进行重新评价。

It has been known that the higher rebleeding rate is one main shortage of the devascularization (ev.) and the gastric mucosal lesions play an important role in it. However, the pathogenesis has not been proved. The purpose of this study was to evaluate the effect of vagotomy, as one part of the combined dev. , on the gastric mucosa in rats with experimental cir-rhotic poetal hypertension. In this study, 240 rats were used, 200 of them were induced into cirrhotic portal hypertension by CCU. They were divided into 4 groups: normal control} non-operative portal hypertension ( NOPHT )} simple dev. ( no vagotomy ) , combined rev. ( vagotomy ) . The value of gastric mucosal blood flow ( GMBF) , gastric juice, gastric acid, gastric adherent mucus ( GAM) , and the activity of pepsin in gastric juice were measured in the 7th and 14th day after operation. The results suggested that the values of GMBF and GAM in the PHT rats were markedly decreased compared with that of the normal controls; There were no significant differences in the values of basic gastric juice, gastric acid, and the activity of pepsin between PHT rats and the normal controls. After operation, the values of GMBF, GAM, gastric acid out put ( AO ) , and the acidity were obvionsly lower than that of the NOPHT rats; and all of these values in vagotomy group were less that of no vagotomy group. But there was no difference in the activity of pepsin among all the groups. The basic gastric juice and AO had recovering tendencies in a short-term after operation. These further demonstrated that the main cause of the gastric mucosal lesions in PHT is the weakness of the protective mechanisms of gastric mucosa, other than the increase of damaging factors; although dev. , especially vagotomy, can decrease the AO, it further reduces the GMBF and GAM; weakens the psotective founction of gastric mucosa that has already been pathologic; increases the rebleeding rates. So we think that it is necessary to evaluate the value of vagotomy in combined dev. again.