Document Detail

Modulation of activin A action and specificity in the rat gonadotrope by protein kinase C.
MedLine Citation:
PMID:  8344195     Owner:  NLM     Status:  MEDLINE    
This study was undertaken to assess the role of protein kinase C (PKC) in activin action in the rat pituitary. Pretreatment with 500 nM phorbol 12-myristate 13-acetate (PMA) for 22-24 h reduced subsequent FSH and LH release (percentage of total cellular FSH and LH released) in response to 100 nM PMA. This action persisted for 2 days after the pretreatment. Pretreatment with 500 nM 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD, a phorbol ester which does not activate PKC) did not affect cell responsiveness to 100 nM PMA. Both PKC-down-regulated cells and cells with a full complement of PKC responded similarly to 100 nM GnRH and 100 microM A23187 during this period. Incubation with 50 ng/ml activin A for 48 h significantly increased both FSH release and total FSH (extracellular plus intracellular) compared to corresponding basal values in PMA-pretreated cells, as well as in vehicle-or 4 alpha PDD-pretreated cells. Activin stimulation of basal FSH release and total FSH was significantly more potent in PMA-pretreated cells than in cells not pretreated with PMA. Activin did not alter basal LH release or total LH in vehicle- or 4 alpha PDD-pretreated cells but significantly increased both in PMA-pretreated cells. When PMA was present only during the initial 2 h of the 22- to 24-h pretreatment period at 50 nM, PKC was not down-regulated. In these cells, the potency of activin stimulation of basal FSH release was not affected, but stimulation of basal LH release by activin was still observed. These results suggest that PKC is not required for activin to stimulate FSH release but is involved as a modulator of potency and specificity of the activin action.
T Katayama; P M Conn
Related Documents :
9514905 - The protein kinase c activator, phorbol ester, elicits disparate functional responses i...
7664625 - Cell cycle progression and phenotypic modification of ki67 antigen-negative g1- and g2-...
2318965 - Regulation of megakaryocyte phenotype in human erythroleukemia cells.
7500645 - Differential expression of c-myc, max and mxi1 in human myeloid leukemia cells during r...
22027505 - Organic anion transporter 1 (oat1) involved in renal cell transport of aristolochic aci...
22105075 - Action of protein disulfide isomerase on proinsulin exit from endoplasmic reticulum of ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Endocrinology     Volume:  133     ISSN:  0013-7227     ISO Abbreviation:  Endocrinology     Publication Date:  1993 Aug 
Date Detail:
Created Date:  1993-09-03     Completed Date:  1993-09-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0375040     Medline TA:  Endocrinology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  496-504     Citation Subset:  AIM; IM    
Department of Pharmacology, University of Iowa College of Medicine, Iowa City 52242-1109.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Alkaloids / pharmacology
Calcimycin / pharmacology
Dimethyl Sulfoxide / pharmacology
Follicle Stimulating Hormone / secretion*
Gonadotropin-Releasing Hormone / pharmacology
Inhibins / pharmacology*
Luteinizing Hormone / secretion*
Pituitary Gland / drug effects,  secretion*
Protein Kinase C / antagonists & inhibitors,  metabolism*
Rats, Sprague-Dawley
Tetradecanoylphorbol Acetate / pharmacology
Grant Support
Reg. No./Substance:
0/Alkaloids; 104625-48-1/Activins; 16561-29-8/Tetradecanoylphorbol Acetate; 33515-09-2/Gonadotropin-Releasing Hormone; 52665-69-7/Calcimycin; 57285-09-3/Inhibins; 62996-74-1/Staurosporine; 67-68-5/Dimethyl Sulfoxide; 9002-67-9/Luteinizing Hormone; 9002-68-0/Follicle Stimulating Hormone; EC Kinase C

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Plasma membrane changes in the rat corpus luteum induced by oxygen radical generation.
Next Document:  Endothelin inhibits basal and stimulated release of prolactin by human decidual cells.