Linked Life Data

9254669

Source:http://linkedlifedata.com/resource/pubmed/id/9254669

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1997-9-23
pubmed:abstractText
Whole-cell patch-clamp recordings were performed together with time-resolved measurements of membrane capacitance (Cm) in nerve terminals acutely dissociated from neurohypophysis of adult rats to investigate modulation of Ca2+ currents and secretion by activation of opioid receptors. Bath superfusion of the kappa-opioid agonists U69,593 (0.3-1 microM), dynorphin A (1 microM), or U50,488H (1-3 microM) reversibly suppressed the peak amplitude of Ca2+ currents 32. 7 +/- 2.7% (in 41 of 56 terminals), 37.4 +/- 5.3% (in 5 of 8 terminals), and 33.5 +/- 8.1% (in 5 of 10 terminals), respectively. In contrast, tests in 11 terminals revealed no effect of the mu-opioid agonist [D-Pen2,5]-enkephalin (1-3 microM; n = 7) or of the delta-agonist Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol (1 microM; n = 4) on Ca2+ currents. Three components of high-threshold current were distinguished on the basis of their sensitivity to blockade by omega-conotoxin GVIA, nicardipine, and omega-conotoxin MVIIC: N-, L-, and P/Q-type current, respectively. Administration of U69,593 inhibited N-type current in these nerve terminals on average 32%, whereas L-type current was reduced 64%, and P/Q-type current was inhibited 28%. Monitoring of changes in Cm in response to brief depolarizing steps revealed that the kappa-opioid-induced reductions in N-, L-, or P/Q-type currents were accompanied by attenuations in two kinetically distinct components of Ca2+-dependent exocytotic release. These data provide strong evidence of a functional linkage between blockade of Ca2+ influx through voltage-dependent Ca2+ channels and inhibitory modulation of release by presynaptic opioid receptors in mammalian central nerve endings.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6565-74
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Kappa-opioid receptor activation modulates Ca2+ currents and secretion in isolated neuroendocrine nerve terminals.
pubmed:affiliation
Department of Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0622, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't