Publication Date:
1988-01-01
Description:
Multiple types of calcium channels have been found in neurons, but uncertainty remains about which ones are involved in stimulus-secretion coupling. Two types of calcium channels in rat sympathetic neurons were described, and their relative importance in controlling norepinephrine release was analyzed. N-type and L-type calcium channels differed in voltage dependence, unitary barium conductance, and pharmacology. Nitrendipine inhibited activity of L-type channels but not N-type channels. Potassium-evoked norepinephrine release was markedly reduced by cadmium and the conesnail peptide toxin omega-Conus geographus toxin VIA, agents that block both N- and L-type channels, but was little affected by nitrendipine at concentrations that strongly reduce calcium influx, as measured by fura-2. Thus N-type calcium channels play a dominant role in the depolarization-evoked release of norepinephrine.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hirning, L D -- Fox, A P -- McCleskey, E W -- Olivera, B M -- Thayer, S A -- Miller, R J -- Tsien, R W -- DA02121/DA/NIDA NIH HHS/ -- HL13306/HL/NHLBI NIH HHS/ -- NS24067/NS/NINDS NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1988 Jan 1;239(4835):57-61.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacological and Physiological Sciences, University of Chicago, IL 60637.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2447647" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Calcium/*physiology
;
Calcium Channel Blockers/pharmacology
;
Electric Conductivity
;
Ganglia, Sympathetic/*physiology
;
In Vitro Techniques
;
Ion Channels/*physiology
;
Membrane Potentials
;
Norepinephrine/*secretion
;
Rats
;
Secretory Rate/drug effects
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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