Document Detail


Forskolin enhances calcium-evoked prolactin release from 7315c tumor cells without increasing the cytosolic calcium concentration.
MedLine Citation:
PMID:  3010075     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The 7315c prolactin-secreting tumor cell was used as a model of a normal pituitary cell in order to study the enhancement by adenosine 3',5'-cyclic monophosphate (cAMP) of calcium-evoked hormone release. Forskolin and, by implication, cAMP had little effect on basal hormone release during a 10-min incubation period. Ionomycin and a high potassium concentration, treatments which enhanced the cytosolic calcium concentration, increased hormone release. When cells were exposed to forskolin prior to and during a challenge with either ionomycin or high potassium, a synergistic effect on prolactin release was observed. 8-Bromoadenosine 3',5'-cyclic monophosphate mimicked forskolin in enhancing ionomycin-evoked prolactin release while having little effect of its own on hormone release. Forskolin did not alter the increase in cytosolic calcium concentration elicited by either ionomycin or high potassium, nor did it increase the potency of ionomycin in enhancing prolactin release. The calcium channel antagonist, D-600, did not alter ionomycin-induced release or its enhancement by forskolin; D-600 blocked potassium-induced prolactin release. Ionomycin had no effect on basal cAMP synthesis by tumor cells and inhibited slightly the forskolin-induced increase in nucleotide synthesis. The results suggest that cAMP acts, at a site distal to the entry of calcium into the cytosol, to enhance the amount of prolactin released in response to an increase in the cytosolic calcium concentration.
Authors:
E A Frey; J W Kebabian; S Guild
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Molecular pharmacology     Volume:  29     ISSN:  0026-895X     ISO Abbreviation:  Mol. Pharmacol.     Publication Date:  1986 May 
Date Detail:
Created Date:  1986-06-23     Completed Date:  1986-06-23     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0035623     Medline TA:  Mol Pharmacol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  461-6     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
8-Bromo Cyclic Adenosine Monophosphate / pharmacology
Aminoquinolines / diagnostic use
Animals
Calcium / analysis*,  physiology
Cell Line
Cyclic AMP / biosynthesis
Cytosol / analysis*
Ethers / pharmacology
Forskolin / pharmacology*
Ionomycin
Pituitary Neoplasms / secretion*
Potassium / pharmacology
Prolactin / immunology,  secretion*
Rats
Chemical
Reg. No./Substance:
0/Aminoquinolines; 0/Ethers; 23583-48-4/8-Bromo Cyclic Adenosine Monophosphate; 56092-81-0/Ionomycin; 60-92-4/Cyclic AMP; 66428-89-5/Forskolin; 7440-09-7/Potassium; 7440-70-2/Calcium; 83014-44-2/Quin2; 9002-62-4/Prolactin

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


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