Protective effect of enriched diet plus growth hormone administration on radiation-induced intestinal injury and on its evolutionary pattern in the rat.

Adequate nutritional support can enhance the protective action of growth hormone in radiation-induced mucositis. Our aim is to address the evolutionary pattern of radiation injury to the small intestine of rats fed a high-protein diet and treated with growth hormone before irradiation. Male Wistar rats were fed a high-protein diet and killed two, four or seven days after irradiation. Animals were given either growth hormone or saline. The combination of growth hormone and high-protein diet reduced mortality, increased mucosal height and crypt proliferation, and reduced apoptosis from day 2 to day 7 after irradiation. Bacterial translocation was increased in rats fed the high-protein formula. Insulin-like growth factor was reduced by radiation and further reduced by the high-protein diet. The combination of growth hormone and high-protein diet protects from the damage caused by radiation to the bowel and accelerates its recovery. This effect does not seem to be mediated through insulin-like growth factor levels.