PROTEIN-KINASE-C ISOZYMES DURING LIVER-REGENERATION

Protein kinase C isozyme (alpha, beta, delta and zeta) activities have been studied in compensatory cell proliferation at 20 and 24 hours af ter partial hepatectomy. Chromatographic analysis of PKC isozymes in m ale rats showed an activation of delta at 20 h after partial hepatecto my and of alpha, beta and zeta at 24 in correspondence with S phase pe ak. A peculiar sexual dimorphism, which matched sexual differences in DNA synthesis, has been observed. The administration of an excess of c holine was able to modulate the protein kinase C isozyme pattern in fe males in relation to DNA synthesis and c-myc expression. Our data sugg est that alpha, beta and zeta PKC positively regulated, while delta ne gatively controlled the liver compensatory growth after partial hepate ctomy. (C) 1995 Academic Press, Inc.