[Endothelin levels under water-immersion stress in rats].

Rats with water-immersion stress-induced ulcer were prepared to determine the levels of ET in blood and gastric tissues, and their relationship with the gastric mucosal blood flow, PGs and pathogenesis in the gastric mucosa were evaluated. Pathology in the gastric mucosa appeared an hour after stress loading, while blood flow rate decreased significantly 30 minutes later. PGE2 increased 30 minutes later, then decreased. PGI2 decreased significantly. Blood ET level was 1.22 +/- 0.50 pg/ml for the controls, but this increased remarkably after one hour and significantly peaked after two hours of water immersion. The level of ET in the gastric tissues was 25.87 +/- 1.63 pg/g tissue for the controls, and this increased markedly after two hours of immersion, reaching a significant peak. In the present study, increased in endogenic ET due to stress were confirmed, and the results suggested the possibility of ET being involved in the pathogenesis of ulcer.