Role of intracellular free Ca~(2+) concentration in the regulation of calcium-activated chloride channels in rat pulmonary artery smooth muscle cells
- VernacularTitle:[Ca~(2+)]_i对大鼠肺动脉平滑肌细胞膜钙激活氯离子通道的调节作用
- Author:
Zhao YANG
;
Zhenxiang ZHANG
;
Yongjian XU
;
Yaqing LI
;
Tao YE
- Publication Type:Journal Article
- Keywords:
Chloride channels;
Calcium;
Pulmonary artery;
Muscle, smooth;
Hypoxic pulmonary vasoconstriction
- From:
Chinese Journal of Pathophysiology
1989;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
AIM: To investigate the role of intracellular free Ca2+ concentration ([Ca2+]i) in the regulation of calcium-activated chloride (ClCa) channels in pulmonary artery smooth muscle cells (PASMCs) of rats under normoxic, acute and chronic hypoxic conditions. METHODS: Acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca2+ indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs in normal and chronic hypoxic condition. The influences of ClCa channels on PASMCs proliferation were assessed by MTT assay. RESULTS: (1) The ClCa channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) produced inhibitory effects on acute hypoxia-evoked contractions in pulmonary artery. (2) Under chronic hypoxic condition, [Ca2+]i was increased. In normoxic condition, [Ca2+]i was (123.63?18.98) nmol/L, and in hypoxic condition, [Ca2+]i was (281.75?16.48)nmol/L (P0.05). (4) Chronic hypoxic increased [Ca2+]i which opened ClCa channels. The NFA and IAA-94 blocked them and decreased [Ca2+]i from (281.75?16.48)nmol/L to (117.66?15.36)nmol/L (P
