Document Detail

Effects of calcium-antagonists on norepinephrine release from sympathetic nerve endings in rat mesenteric vasculature.
MedLine Citation:
PMID:  3761570     Owner:  NLM     Status:  MEDLINE    
The present study was designed to investigate whether Ca-antagonists influence norepinephrine release from the sympathetic nerve endings in resistance vessels. Isolated mesenteric vascular preparations of rats, perfused with Ringer-Locke solution, were used to determine the effects of verapamil or diltiazem on norepinephrine release from sympathetic nerve terminals. Pressor responses to exogenous norepinephrine and electrical nerve stimulation were recorded, and the norepinephrine contents of the perfusate were measured before and after the electrical nerve stimulation, using high pressure liquid chromatography with an electrochemical detector. Pressor responses to exogenous norepinephrine and electrical nerve stimulation were depressed dose-dependently by verapamil and diltiazem. The inhibition of the pressor responses for nerve stimulation was greater than exogenous norepinephrine. Both verapamil and diltiazem reduced norepinephrine release from the mesenteric arterial beds after the electrical nerve stimulation. These results indicate that Ca++-antagonists, such as verapamil and diltiazem, have inhibitory effects on norepinephrine release from the sympathetic nerve endings, in addition to their direct actions on the vascular smooth muscle. It is also suggested that the presynaptic inhibitory action of Ca++-antagonists could be due to the blockade of Ca++-channels in nerve cell terminals, which may be important in the clinical use of Ca-antagonists.
K Tsuda; M Kuchii; I Nishio; Y Masuyama
Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Japanese heart journal     Volume:  27     ISSN:  0021-4868     ISO Abbreviation:  Jpn Heart J     Publication Date:  1986 May 
Date Detail:
Created Date:  1986-11-20     Completed Date:  1986-11-20     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0401175     Medline TA:  Jpn Heart J     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  395-402     Citation Subset:  IM    
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MeSH Terms
Calcium Channel Blockers / pharmacology*
Diltiazem / pharmacology
Mesenteric Arteries / innervation*
Nerve Endings / secretion*
Norepinephrine / secretion*
Sympathetic Nervous System / drug effects*,  secretion
Verapamil / pharmacology
Reg. No./Substance:
0/Calcium Channel Blockers; 42399-41-7/Diltiazem; 51-41-2/Norepinephrine; 52-53-9/Verapamil

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

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