SOMATOSTATIN ATTENUATES THE HYPERDYNAMIC CIRCULATORY STATE IN THE GASTRIC-MUCOSA OF RATS WITH PORTAL-HYPERTENSION

Background: Portal hypertensive gastropathy is characterized by a hype rdynamic circulatory state in the gastric mucosa. We assessed the effe ct of bolus injection of somatostatin on gastric mucosal perfusion in a rat model of portal hypertension. We tested the hypothesis that soma tostatin will reduce gastric mucosal perfusion in portal hypertension. Methods: Portal hypertension was induced by two-stage portal vein lig ation (PVL). Two weeks after PVL significant elevation of portal venou s pressure was demonstrated. Gastric mucosal hemodynamic changes were measured by reflectance spectrophotometry, which records the indexes o f mucosal hemoglobin oxygen saturation (ISO2) and mucosal hemoglobin c oncentration (IHB). Results: After an intravenous bolus of 1 mu g soma tostatin significant reductions of ISO2 and IHB were demonstrated in t he rats with PVL (ISO2, -34 +/- 5%; IHB, -15 +/- 2%) and the controls (ISO2, -26 +/- 4%; IHB, -15 +/- 2%). A dose-response relationship was shown by using 0.01, 0.1, and 1 mu g of somatostatin. Somatostatin did not induce other hemodynamic changes except a transient drop in syste mic blood pressure of 8-10%. Conclusion: The significant reductions of gastric mucosal ISO2 and IHB by somatostatin support the hypothesis t hat somatostatin is capable of attenuating the hyperdynamic circulator y state in the gastric mucosa of rats with portal hypertension and may have a beneficial effect on portal hypertensive gastropathy. This hyp othesis deserves to be evaluated in clinical studies.