Prolactin activates protein kinase C and stimulates growth-related gene expression in rat liver.
We have examined the effect of prolactin (PRL) on growth-related gene expression, protein kinase C (PKC) activity and diacylglycerol (DAG) mass in rat liver. Hepatic levels of messenger (m)RNA for c-myc, ornithine decarboxylase (ODC) and beta-actin increased in a dose-dependent manner within 1 h after PRL administration. Prolactin also caused a transient elevation of liver DAG levels and particulate-associated PKC activity. The PRL-provoked increases in DAG mass and particulate PKC activity were coincident and maximal at 20 min and began declining toward control levels by 30 min. These results suggest a temporal relationship between PRL-stimulated DAG accumulation and PKC activation. Furthermore, the subsequent rapid induction of growth-related gene expression provides new information on the role of PRL as a hepatic mitogen.
Crowe
P D
PD
Department of Pharmacology and Therapeutics, University of South Florida, Tampa.
Buckley
A R
AR
Zorn
N E
NE
Rui
H
H
D000199:Actins / Q000235:genetics; D000375:Aging; D000818:Animals; D015342:DNA Probes; D004075:Diglycerides / Q000378:metabolism*; D004789:Enzyme Activation; D015870:Gene Expression / Q000187:drug effects; D016259:Genes, myc / Q000187:drug effects; D006657:Histones / Q000235:genetics; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D008297:Male; D009955:Ornithine Decarboxylase / Q000235:genetics; D011388:Prolactin / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D000199:Actins; D015342:DNA Probes; D004075:Diglycerides; D006657:Histones; D012333:RNA, Messenger; D012313:RNA; D011388:Prolactin; D011493:Protein Kinase C; D009955:Ornithine Decarboxylase