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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1-2
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pubmed:dateCreated |
1992-8-28
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pubmed:abstractText |
Nerve endings of the magnocellular neurohypophysial neurones possess kappa-opioid receptors. Using a preparation of isolated terminals from the neurohypophysis we studied kappa-opioid effects on secretion of oxytocin and vasopressin and on intracellular Ca2+ concentration ([Ca2+]i) measured fluorimetrically or using digital video imaging with Fura-2. The dihydropyridine Ca(2+)-channel antagonist nicardipine reduced [Ca2+]i responses to K(+)-depolarisation (30-40 mM K+) by 55-75% and inhibited evoked secretion of oxytocin and vasopressin to a similar extent. The selective kappa-receptor agonist D-Pro10 Dynorphin A 1-11 (DPDYN) substantially inhibited K+ evoked secretion of oxytocin by 40-90% and secretion of arginine vasopressin (AVP) by 20-50%. DPDYN caused only a 10% reduction in the average total population [Ca2+]i response to K+ depolarisation. No sub-population of inhibitory responses was observed when samples of individual terminal [Ca2+]i responses were examined with imaging. Although kappa-receptors are coupled to Ca(2+)-channels at neuronal somata our data suggest that alternative effector mechanisms operate in these secretory nerve endings.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Arginine Vasopressin,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Dynorphins,
http://linkedlifedata.com/resource/pubmed/chemical/Fura-2,
http://linkedlifedata.com/resource/pubmed/chemical/Oxytocin,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Opioid,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Opioid, kappa,
http://linkedlifedata.com/resource/pubmed/chemical/dynorphin (1-11), Pro(10)-
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-8993
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
6
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pubmed:volume |
574
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
138-46
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1353398-Animals,
pubmed-meshheading:1353398-Arginine Vasopressin,
pubmed-meshheading:1353398-Calcium,
pubmed-meshheading:1353398-Calcium Channels,
pubmed-meshheading:1353398-Dynorphins,
pubmed-meshheading:1353398-Exocytosis,
pubmed-meshheading:1353398-Fluorometry,
pubmed-meshheading:1353398-Fura-2,
pubmed-meshheading:1353398-Image Processing, Computer-Assisted,
pubmed-meshheading:1353398-Male,
pubmed-meshheading:1353398-Membrane Potentials,
pubmed-meshheading:1353398-Nerve Endings,
pubmed-meshheading:1353398-Oxytocin,
pubmed-meshheading:1353398-Peptide Fragments,
pubmed-meshheading:1353398-Pituitary Gland, Posterior,
pubmed-meshheading:1353398-Rats,
pubmed-meshheading:1353398-Receptors, Opioid,
pubmed-meshheading:1353398-Receptors, Opioid, kappa,
pubmed-meshheading:1353398-Video Recording
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pubmed:year |
1992
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pubmed:articleTitle |
Activation of kappa-opioid receptors inhibits depolarisation-evoked exocytosis but not the rise in intracellular Ca2+ in secretory nerve terminals of the neurohypophysis.
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pubmed:affiliation |
Department of Neuroendocrinology, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, U.K.
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pubmed:publicationType |
Journal Article,
Comparative Study,
In Vitro
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