Calcium Efflux in Rat Tail Artery during Potassium Induced Relaxation

R. Clinton Webb, Paul M. Vanhoutte, David F. Bohr

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The current study investigates the mechanism by which the concentration of activator Ca2+ is decreased during potassium induced relaxation of vascular smooth muscle. Helically cut strips of rat tail artery were mounted between a fixed base and force transducers; isometric contractions were recorded. The arterial strips relaxed in response to potassium after contraction induced by norepinephrine in potassium-free solution. The efflux of 45Ca2+ from the strips was stimulated by norepinephrine during the potassium-free cycle. This increase in efflux was prevented during potassium induced relaxation. D-600, an inhibitor of transmembrane Ca2+ flux, reduced the magnitude of potassium induced relaxation by 35%. These observations suggest that relaxation in response to potassium is the result of a decrease in membrane permeability to Ca2+ coupled with an increase in Ca2+ sequestration at intracellular sites.

Original languageEnglish (US)
Pages (from-to)252-256
Number of pages5
JournalProceedings of the Society for Experimental Biology and Medicine
Issue number3
StatePublished - Jul 1980
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


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