THE PATHOGENETIC ROLE OF ENDOGENOUS ANGIOTENSIN-II IN STRESS-ULCER INOBSTRUCTIVE-JAUNDICE RATS

Objective To investigate the pathogenetic role of endogenous angiotens in II (Ang II) in the mechanism of stress ulcer in obstructive jaundic e rats and to detect the effect of angiotensin converting enzyme inhib itor (ACEI) on stress ulcer in obstructive jaundice rats. Methods Afte r common bile duct ligation (CBDL) in Wistar rats, the content of plas ma and gastric mucosal Ang II, gastric mucosal blood flow (GMBF) and g astric mucosal damage were measured, and the relationship among them w as analyzed.Results The plasma Ang II contents increased much more sig nificantly at 1, 3, 7 and 14 days following CBDL than those in non-CBD L rats (P < 0.05, < 0.01, < 0.01 and < 0.01, respectively). Within 120 minutes following cold-restraint stress, plasma and gastric mucosal A ng II contents were elevated, GMBF decreased, and ulcer index and gast ric mucosal damage increased more significantly than those in non-cold -restraint stress rats (P < 0.05, < 0.05, < 0.01, < 0.01 and < 0.05, r espectively). Administration of an ACEI, enalaprili, to CBDL rats (5 m g.kg(-1).day(-1), orally for two days) before stress reduced both the plasma and gastric mucosal Ang II levels, inhibited the decrease of GM BF and decreased ulcer index and gastric mucosal damage (P < 0.001, < 0.01, < 0.01, < 0.01 and < 0.05, respectively). Conclusion The endogen ous Ang II plays a significant pathogenetic role in the development of stress ulcer in obstructive jaundice rats, and ACEI may prevent stres s ulcer.