Protein Kinase C Isozymes during Liver Regeneration

Abstract

Protein kinase C isozyme (α, β, δ and zeta) activities have been studied in compensatory cell proliferation at 20 and 24 hours after partial hepatectomy. Chromatographic analysis of PKC isozymes in male rats showed an activation of δ at 20 h after partial hepatectomy and of α, β and zeta at 24 in correspondence with S phase peak. A peculiar sexual dimorphism, which matched sexual differences in DNA synthesis, has been observed. The administration of an excess of choline was able to modulate the protein kinase C isozyme pattern in females in relation to DNA synthesis and c-myc expression. Our data suggest that α, β and zeta PKC positively regulated, while δ negatively controlled the liver compensatory growth after partial hepatectomy.