EFFECTS OF GROWTH-HORMONE AND INSULIN-LIKE GROWTH-FACTOR-I ON RADIATION ENTERITIS - A COMPARATIVE-STUDY

The effect of growth hormone (GH) and insulin-like growth factor-I (IG F-I) on intestinal mucosal integrity and bacterial translocation after abdominal radiation was studied in rats. Animals were divided into th e following groups: I (control), II (radiation), III (radiation plus G H) and IV (radiation plus IGF-I). Radiation (1,100 cGy) was administer ed on the Ist day to groups II, III and IV. GH [0.25 mg/kg body weight (BW) s.c, once daily] was administered on days 1, 2 and 3 to group II I, and IGF-I (0.1 mg/kg BW s.c. twice daily) was given on days 1, 2 an d 3 to group IV. On day 4, animals were sacrificed. Cultures of the me senteric lymph nodes (MLN) and blood cultures from aorta and portal ve in were performed. The number of villi per centimeter (V/cm), the vill us height (Vh), mitoses per crypt (M/C) and protein and DNA contents o f the mucosa were evaluated in samples from the terminal ileum. Radiat ion increased the number of positive MLN cultures, while treatment wit h GH and IGF-I reduced them significantly. V/cm, Vh, M/C, protein and DNA contents were significantly increased in all irradiated animals tr eated with GH and IGF-I. In conclusion both GH and IGF-I are not only capable of improving the mucosal integrity but also to reduce the bact erial translocation that follows intestinal radiation. In small doses IGF-I could reproduce the effects of GH and in some parameters the eff ects were more pronounced, although not statistically significant. Thi s suggests that the effects of GH on intestine could be mediated throu gh the local and systemic generation of IGF-I.