title: Prolactin-provoked alterations of cytosolic, membrane, and nuclear protein kinase C following partial hepatectomy.
abstract: The adenohypophyseal polypeptide hormone prolactin is a potent liver mitogen, stimulating cell cycle progression, an effect that appears coupled to increasing protein kinase C activity in membrane and nuclear fractions. Here, we examine whether hepatocyte proliferation, stimulated by partial hepatectomy, is associated with altered serum prolactin or protein kinase C activation. Within 5-15 min of liver resection, serum prolactin concentrations elevate significantly. Protein kinase C activity in hepatic cytosol decreases significantly, and membrane and nuclear PKC activity increase by 30 min. Hypophysectomy prior to partial hepatectomy abrogates any effect of liver resection on protein kinase C activation in the hepatic remnant. Based upon these data, it is suggested that the rapid increase in serum prolactin seen after partial hepatectomy may be linked to protein kinase C activation, which in turn stimulates the hepatic proliferative response that is essential for hepatic regeneration.
authors.affiliation: Department of Pharmacology, Kirksville College of Osteopathic Medicine, Missouri 63501.
authors.forename: A R
authors.initials: AR
authors.lastname: Buckley
authors.forename: P D
authors.initials: PD
authors.lastname: Crowe
authors.forename: P A
authors.initials: PA
authors.lastname: Bauman
authors.forename: L A
authors.initials: LA
authors.lastname: Neumayer
authors.forename: H E
authors.initials: HE
authors.lastname: Laird
authors.forename: D H
authors.initials: DH
authors.lastname: Russell
authors.forename: C W
authors.initials: CW
authors.lastname: Putnam
mesh_terms: D000818:Animals; D002455:Cell Division / Q000502:physiology; D006498:Hepatectomy; D007016:Hypophysectomy; D008099:Liver / Q000166:cytology / Q000201:enzymology*; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000502:physiology; D011388:Prolactin / Q000097:blood / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D011388:Prolactin; D011493:Protein Kinase C