In:
Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 13, No. 6 ( 1993-11), p. 969-977
Abstract:
We examined whether Ca 2+ channel function in the resting state alters the resting tone and Ca 2+ -activated K + (K Ca ) channel function in dog basilar artery: data were compared with findings in the mesenteric artery. Isolated dog basilar artery maintained a myogenic tone; that is, the resting tone decreased when either the Krebs solution was replaced with a Ca 2+ -free solution or nifedipine was added. The basal 45 Ca influx in the resting state of the basilar artery was significantly increased compared with that in the mesenteric artery, and this increase in the basilar artery was reduced by nifedipine. The addition of charybdotoxin (ChTX), a blocker of large-conductance K Ca channels, to the resting strips caused a concentration-dependent contraction in the basilar artery but not in the mesenteric artery. The ChTX-induced contraction in the basilar artery was abolished by nifedipine. In resting strips preloaded with 86 Rb, the basal 86 Rb efflux rate constant was significantly greater in the basilar artery than in the mesenteric artery. The addition of nifedipine to the resting strips decreased the basal 86 Rb efflux rate constant only in the basilar artery. These results suggest that the transmembrane Ca 2+ influx via L-type voltage-dependent Ca 2+ channels was significantly increased in the resting state of the basilar artery and that the myogenic tone was therefore maintained and the ChTX-sensitive K Ca channels were highly activated.
Type of Medium:
Online Resource
ISSN:
0271-678X
,
1559-7016
DOI:
10.1038/jcbfm.1993.121
Language:
English
Publisher:
SAGE Publications
Publication Date:
1993
detail.hit.zdb_id:
2039456-1
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