Growth hormone and somatostatin interaction in the ulcerogenic effect of cysteamine in female rats

It is known that cysteamine's ulcerogenic effect depends, among others, on a depletion of somatostatin (SRIH). Since growth hormone (GH) affects the release of hypothalamic SRIH, we have studied the influence of GH and the GH-SRIH interaction on the severity of gastric mucosa lesions induced by cysteamine. Female rats of the Sprague-Dawley strain were pretreated with GH (1 mg/kg) and subjected to cysteamine-induced gastric lesions. We found that these animals showed an increased mortality and severity of gastric lesions. Pretreatment with SRIH (25 or 50 μg/kg) was followed by a decrease in mortality and of incidence and severity of gastric mucosa lesions as compared to those found in control animals pretreated with saline. The dose of 5μg/kg was ineffective in this respect. The combined administration of GH and SRIH revealed that cysteamine ulcerogenic action remained unchanged. It is possible that high levels of plasma GH, as induced by exogenous GH administration, may decrease the release of gastro-intestinal SRIH and this in turn may potentiate the ulcerogenic activity of cysteamine.