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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1993-4-30
pubmed:abstractText
Pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates catecholamine secretion from cultured porcine adrenal medullary chromaffin cells in a dose-dependent manner with the half-maximal and maximal doses of 30 nM and 1 microM, respectively. Either removal of extracellular Ca2+ or addition of Gd3+, an inorganic Ca2+ channel blocker, very potently inhibits PACAP-induced catecholamine secretion. Both nicardipine (1 microM) and methoxyverapamil (1 microM), blockers of voltage-dependent Ca2+ channels, are also effective in inhibiting PACAP-induced catecholamine secretion. When the intracellular free Ca2+ concentration ([Ca2+]i) is measured in a fura 2-loaded single chromaffin cell, PACAP is found to cause a sustained increase in [Ca2+]i by mobilizing Ca2+ from both extra- and intracellular pools. It is also found that PACAP stimulates the production of inositol phosphates in a dose-dependent manner, which is not abolished by removal of extracellular Ca2+ unlike the case of nicotine. PACAP increases cAMP content in chromaffin cells in a dose-dependent manner. Removal of extracellular Ca2+ enhances PACAP-induced cAMP production but strongly inhibits PACAP-induced catecholamine secretion. Pretreatment of cells with adenosine-3':5'-monophosphothioate, cyclic, Rp-isomer, a cAMP antagonist, does not block PACAP-induced catecholamine secretion. The addition of forskolin or 3-isobutyl-1-methylxanthine does not enhance the PACAP-induced catecholamine secretion. These results indicate that PACAP activates voltage-dependent Ca2+ channels and phospholipase C as well as adenylate cyclase in cultured porcine adrenal medullary cells and strongly suggest that PACAP-induced catecholamine secretion is mainly mediated by activation of voltage-dependent Ca2+ channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1757-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Ca(2+)-dependent stimulatory effect of pituitary adenylate cyclase-activating polypeptide on catecholamine secretion from cultured porcine adrenal medullary chromaffin cells.
pubmed:affiliation
Department of Clinical Pathology, University of Tsukuba, Ibaraki, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't