Experimental Study On Nitrogen Monoxide (NO) And Induced Nitricoxide Synthase (iNOS) In Plasma And Tissue Of Stomach Of Obstructive Jaundice In Rats

Acute gastric mucosa pathological changes of obstructive jaundice (OJ)can cause gastrointestinal bleeding and its mortality and complication rate are very high. However, the mechanism is undefined. There is no report about the impairment effect of NO to gastric mucosa in stress state of obstructive jaundice. The purpose of this study is to investigate the mechanism of acute gastric mucosa pathological change of obstructive jaundice and to provide theory for clinical prevention and therapy through observing the change of stomach secretion, the plasma NO content and stomach tissue iNOS. METHODS: In this study, 32 female Wistar rats (weight 250+30g ) were divided into 2 random groups: fake operation(FO) (N=16);obstructive jaundice (OB)(N=16). Two weeks later, each groups were divided into 2 random groups respectively: control(C)(N=8) and stress(S)(N=8).The content of plasma NO; total bilirubin and Serum glutami pyruvate transaminase ( SGPT) and the volume of gastric juice ; pepsin activity; total acidity and free acidity were measured. After gastric mucosa injury index determination, stomach samples were made into paraffin sections, and the HE and ABPAS staining for common morphology and neutral mucus area density ware performed. Hybridization in situ for iNOS of tissue ofstomach was performed. RESULTS: (1) Compared with FO and FO+S groups, in OJ and OJ+S groups, increase in total bilirubin and SGPT ware statistically significantly (P<0.01). (2) AS to gastric mucosa injury index, OJ+S group was the most serious; the next was FO+S and OJ groups were less, and there were no gastric mucosa damage in FO group, the differences ware significant (P<0.01 respectively) between each groups. (3) Compared with contrasts, in stress state, increase in pepsin activity; total acidity and free acidity of gastric juice and the content of neutral mucus of gastric mucosa was statistically significantly (P<0.01). (4) The content of plasma NO in OJ and OJ+S groups increased more significantly than FO and FO+S groups, there was differences between each groups (P<0.01, respectively). There was no iNOS expression in FO group and in OJ group and the increase of iNOS expression was stastitically significant (P<0.01) compared with the other 2 groups. (5) Punctual or streaky haemorrhagia could be found in Gastric mucosa through gross observation, small ulcer was found occasionally. In HE staining sections, there was no gastric mucosa damage in FO group, however, gastric mucosa integrity destruction; parts of mucosa cells necrosis; nucleus extinction; submucous haemorrhagia; blood vessel expansion; blood congestion were found in other 3 groups. In ABPAS staining sections, there was no abnormality in FO group, pathologic changes were found in other 3 groups including covering epithelium integrity destruction; various mucus cells increase; gland expansion and so on. In hybridization in situ sections, there were no iNOS positive cells in FO group, iNOS positive cells were found in other 3 groups in mucous layer , tela submucosa and vascular wall. CONCLUSION: (1) Increase in gastric mucosa damage index and significant increase in stress state in obstructivejaundice rats suggested that stomach damage factors increase obviously in obstructive jaundice. (2) The obvious increase in plasma NO and iNOS of tissue of stomach are the reason leading to acute gastric mucosa pathological change in obstructive jaundice and obstructive jaundice stress rats.