Insulin-like Growth Factor-I (IGF-I) in Malnourished Rats Following Major Hepatic Resection

We examined the effect of malnutrition on liver regeneration and changes in plasma insulin-like growth factor-I (IGF-I) concentrations, and the effect of the administration of IGF-I to rats following hepatic resection. Twenty-nine male Spraugue-Dawley rats were allocated to one of three groups. Group I (n = 11) consisted of normally nourished rats which each underwent a 70% partial hepatectomy by the method of Higgins and Anderson. Group II (n = 8) was composed of malnourished rats which also underwent partial hepatectomies. Group III (n=10) consisted of malnourished rats which each underwent a partial hepatectomy and received 200 μg of exogenous IGF-I for 24h following surgery. Group I rats were permitted to eat ad libitum., rats in Groups II and III received 50% of their normal intake for one week prior to and following hepatectomy. The rats were killed after 48 h of hepatic regeneration, and the livers were weighed and prepared for hamatoxylineosin staining to facilitate an assessment of the number of mitotic cells. Decreases in the remnant liver weights and mitotic indices were more extensive in the malnourished rats. Additionally, malnutrition was associated with low plasma IGF-I concentrations following partial hepatectomy. IGF-I administration was not associated with an improved nitrogen balance following hepatectomy. These results suggest that an adequate nutritional status is essential for liver regeneration, and that malnutrition is associated with lower plasma IGF-I concentrations following partial hepatectomy. An inadequate nutrient supply may abolish the anabolic effect of the administration of IGF-I on nutritional repletion postoperatively