Effects of somatostatin on gastric mucosal histamine and serotonin content in restrained rats

The effects of continuous intravenous perfusion of somatostatin on the incidence of ulcers and the histamine and serotonin gastric mucosal content in rats subjected to 12 h of restraint were studied. 51 sets of Sprague-Dawley male rats (102 animals) were divided at random into two groups. Those in group I were immobilized and treated with an intravenous infusion of isotonic saline solution. Animals in group II were also immobilized and given intravenous cyclic somatostatin dissolved in isotonic saline solution; the initial dose was 25 microgram and a continuous infusion of 2.5 microgram/kg/h was administered thereafter. A decrease in the ulcer index was observed in the rats perfused with somatostatin (p less than 0.01) as well as a decrease in the histamine (p less than 0.001) and serotonin (p less than 0.01) gastric mucosal contents. These effects of somatostatin on restraint-induced stress ulcer in rats are probably to be explained by microcirculatory changes in the gastric mucosa determined by the vasoactive amines (histamine and serotonin). They constitute an important factor in the pathogenesis of these lesions.