Document Detail

Functional role of charybdotoxin-sensitive K+ channels in the resting state of dog basilar artery.
MedLine Citation:
PMID:  7530733     Owner:  NLM     Status:  MEDLINE    
To determine the possible role of Ca(2+)-activated K+ (KCa) channels in the regulation of resting tone of cerebral arteries, the effect of agents which interact with these channels on tension and 86Rb efflux was examined in endothelium-denuded strips of dog basilar artery, and data were compared with findings in the mesenteric artery. The basilar artery maintained a myogenic tone; that is, the resting tone decreased when nifedipine was added. The addition of charybdotoxin, a blocker of large conductance KCa channels, caused a concentration-dependent contraction in the basilar artery but not in the mesenteric artery. In strips preloaded with 86Rb, the basal 86Rb efflux rate constant was significantly greater in the basilar artery than in the mesenteric artery. Nifedipine decreased the basal 86Rb efflux rate constant only in the basilar artery. The basal 45Ca influx in the resting state of the basilar artery was significantly increased when compared with the mesenteric artery and this increase in the basilar artery was reduced by nifedipine. The results suggest that the charybdotoxin-sensitive KCa channels regulate the myogenic tone in the resting state of the basilar artery. The activation of KCa channels in the basilar artery appears to be secondary to the increased transmembrane Ca2+ influx probably via the activation of L-type voltage-dependent Ca2+ channels in the resting state of this artery.
M Asano; K Masuzawa-Ito; T Matsuda; Y Suzuki; H Oyama; M Shibuya; K Sugita
Related Documents :
22735003 - Novel technique of valve-sparing aortic root replacement in two children younger than 3...
22025423 - Fetal intrahepatic gallbladder and topographical anatomy of the liver hilar region and ...
1606363 - Pulmonary autograft replacement of the aortic valve: an evolution of technique.
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of the autonomic nervous system     Volume:  49 Suppl     ISSN:  0165-1838     ISO Abbreviation:  J. Auton. Nerv. Syst.     Publication Date:  1994 Sep 
Date Detail:
Created Date:  1995-03-02     Completed Date:  1995-03-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8003419     Medline TA:  J Auton Nerv Syst     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  S151-5     Citation Subset:  IM    
Department of Pharmacology, Nagoya City University Medical School, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Apamin / pharmacology
Basilar Artery / drug effects,  metabolism*
Calcium / metabolism
Calcium Radioisotopes / diagnostic use
Endothelium, Vascular / physiology
Muscle Tonus / drug effects
Muscle, Smooth, Vascular / drug effects,  metabolism*
Potassium Channels / drug effects*
Rubidium Radioisotopes / diagnostic use
Scorpion Venoms / pharmacology*
Tetraethylammonium Compounds / pharmacology
Reg. No./Substance:
0/Calcium Radioisotopes; 0/Potassium Channels; 0/Rubidium Radioisotopes; 0/Scorpion Venoms; 0/Tetraethylammonium Compounds; 115422-61-2/Charybdotoxin; 24345-16-2/Apamin; 7440-70-2/Calcium

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

Previous Document:  Biological behaviour and morphological characteristics of a transplantable tumour (MM-KMY) derived f...
Next Document:  Cerebrovascular sensory innervation involved in the development of cerebral vasospasm following a su...