Ileocolectomy enhances the regenerative response after partial hepatectomy in the pig

Although portal blood has been shown to be more hepatotrophic than peripheral venous blood, the origin and nature of the factors responsible remain obscure. In this study the effect of partial ileocolectomy (IC) or partial ileal resection (I) on the regenerative response after 50% partial hepatectomy (PH) in the pig was investigated using thymidine kinase activity and mitotic figures as indices of regeneration. IC with 50% partial hepatectomy resulted in a significantly greater regenerative response on the 3rd day than hepatectomy alone or hepatectomy plus partial I. Levels of plasma insulin were elevated after PH and I but not after IC, although there were no significant differences in levels of plasma glucagon or plasma glucose. Levels of aspartate amino-transferase were similar in all groups. These results extend previous data and suggest that the proximal colon may be the source of a regeneration inhibitory factor.