Research

Mechanism of effect of extracellular pH on L-type Ca2+ channel currents in human mesenteric arterial cells


Reference:

Smirnov, S. V., Knock, G. A., Belevych, A. E. and Aaronson, P. I., 2000. Mechanism of effect of extracellular pH on L-type Ca2+ channel currents in human mesenteric arterial cells. American Journal of Physiology-Heart and Circulatory Physiology, 279 (1), H76-H85.

Related documents:

This repository does not currently have the full-text of this item.
You may be able to access a copy if URLs are provided below.

Official URL:

http://ajpheart.physiology.org/cgi/content/abstract/279/1/H76

Abstract

Extracellular pH (pHo) influences vasoconstriction partly by modulating Ca2+ influx through voltage-gated Ca2+ channels in the vasculature. The mechanism of this effect of pHo is, however, controversial. Using the whole cell voltage-clamp technique, we examined the influence of pHo on L-type Ca2+ channel currents in isolated human mesenteric arterial myocytes. Acidification to pH 6.2 and alkalinization to 8.2 from 7.2 decreased by ~50% and increased by 25-30%, respectively, the peak amplitude of Ca2+ and Ba2+ currents (1.5 and 10 mM), with an apparent pKa of 6.8. Activation and inactivation of Ca2+ and Ba2+ currents were shifted toward positive membrane voltages during acidification and in the opposite direction during alkalinization. The relationship between the current amplitude and shifts in the gating parameters in solutions of different pHo conformed closely to that predicted by the Gouy-Chapman model, in which the divalent cation concentration at the outer surface of the membrane varies with the extent to which protons neutralize the membrane surface potential.

Details

Item Type Articles
CreatorsSmirnov, S. V., Knock, G. A., Belevych, A. E. and Aaronson, P. I.
DepartmentsFaculty of Science > Pharmacy & Pharmacology
RefereedYes
StatusPublished
ID Code19914

Export

Actions (login required)

View Item