Effect of hypophysectomy and growth hormone administration on somatostatin and gastrin content in the stomach of rats

Gastrointestinal effects of growth hormone

GH receptor immunoreactivity is found throughout the gastrointestinal tract. GH has proliferative effects upon intestinal epithelium, and influences enteroendocrine cell secretion, calcium absorption, and intestinal amino acid and ion transport. The proliferative effects of GH may be reflected in the increased incidence of neoplastic colonic polyps in individuals with long-term GH excess reported by some investigators. GH also increases hepatic cytochrome P450 expression, potentially altering drug and steroid hormone metabolism. Current clinical research efforts include the use of exogenous GH as a stimulant of gut growth and adaptation in patients who have undergone massive intestinal resection. Exogenous GH is also being studied in animal models of critical illness where it appears to increase intestinal glutamine uptake, which may prevent deterioration of the intestinal mucosal barrier.

Pathogenesis of gastric mucosal damage induced by intraperitoneal administration of gold thioglucose in rats

Rats injected intraperitoneally with gold thioglucose (GTG,0.3mg/g) revealed hemorrhagic lesions in the gastric mucosa 24h after the injection. However, no morphological changes were found in the central nervous system after the injection. The volume of gastric secretion and acid output increased significantly 24h after the injection (P less than 0.01), and gastric emptying was markedly inhibited 24h post administration (P less than 0.01). There were no changes in either blood flow or hexosamine contents in the gastric mucosa. These results indicated that gastric hemorrhagic lesion was associated with increases in gastric secretion and acid output. No significant changes were found in gastrin contents in either plasma or the gastric mucosa. A subdiaphragmatic vagotomy prior to the GTG injection prevented bleeding in the gastric mucosa and lowered the gastric secretion and acid output. This indicated that the mechanism of action of GTG in producing the gastric lesion might be mediated by the vagus nerve.