Regulation of intracellular calcium by cell pH in vascular smooth muscle cells.

摘要: Intracellular calcium (Cai2+) and intracellular pH (pHi) are important regulators of a variety processes. Cai2+ is regulator muscle contraction, but the role pHi unclear. The purpose this study was to determine effect alterations on Cai2+. A7r5 vascular smooth cells (VSMC) were grown confluence glass cover slips. determined with fluorescent probe fura-2 2,7-bis-carboxyethyl-5(6)-carboxy-fluorescein (BCECF). Alkalinization VSMC by exposure 20 mM NH4Cl (delta 0.41 +/- 0.07) resulted in rise from 99 8 146 13 nM (n = 5) presence extracellular Ca2+ (Cao2+). In absence Cao2+, NH4Cl-induced alkalinization also 26 4 nM, n 5). Similar changes observed when alkalinized nigericin KCl buffer (pH 7.7). Neither 100 microM verapamil or 8,8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate HCl (TMB-8) altered alkaline-induced changes. After cellular stores partially depleted AVP Ca2+-free solution, subsequent cell induced no These results demonstrate that VSMCs leads cytosolic via release stores. storage sites appear be same as those sensitive AVP. Thus may regulate thereby play regulation tone.