Trophic Effect of Portal Blood in Maintenance Cultures of Adult Rat Hepatocytes

Abstract

The hepatotrophic effect of portal serum was demonstrated in primary monolayer cultures of adult rat hepatocytes: DNA synthesis in cultures incubated for 4 days with pooled portal serum of fed rats was significantly higher than in cultures with peripheral serum from the same animals. This difference was not observed when portal blood was treated with charcoal or obtained from fasting rats. Portal serum from diabetic rats stimulated DNA synthesis less than portal control serum. The trophic effect of portal serum from normal rats was enhanced after tolbutamide injection. The lost trophic effect of charcoal-treated portal serum was completely restored when insulin was added to reobtain a normal portal immunoreactive insulin concentration. Thus, insulin seems to be the main factor responsible for the hepatotrophic action of portal blood in vitro.

Intrasplenic hepatocyte transplantation: Evaluation of DNA synthesis and proliferation in auxiliary transplanted cells

“…The question whether partial hepatectomy may induce a proliferation tendency in auxiliary, intrasplenically transplanted hepatocytes has to be answered negatively because no increased 3H-thymidine incorporation was to be observed in intraspenically transplanted liver cells after partial hepatectomy. This result would confirm the existence of a hepatotrophic factor arising from the portal system [14,16], which might not influence the proliferation of extrahepatically implanted liver cells. In contrast to this result Jirtle and Michalopoulos [13] demonstrated that s.c. implanted hepatocytes show a similar increase in DNA synthesis as the remaining liver tissue, when a partial hepatectomy is performed.…”