To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute a...To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.展开更多
目的测定中药柴胡(Bupleurun Chinese DC, BCDC)提取物对人肝癌细胞BEL-7402细胞内游离钙离子浓度([Ca2+]i)的影响,以探索柴胡逆转BEL-7402细胞多药耐药的机制.方法以Fura-2/AM为细胞内钙离子的荧光指示剂,用双波长荧光分光光度计分别...目的测定中药柴胡(Bupleurun Chinese DC, BCDC)提取物对人肝癌细胞BEL-7402细胞内游离钙离子浓度([Ca2+]i)的影响,以探索柴胡逆转BEL-7402细胞多药耐药的机制.方法以Fura-2/AM为细胞内钙离子的荧光指示剂,用双波长荧光分光光度计分别测定不同条件下的BEL-7402细胞内[Ca2+]i.结果柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降(P<0.001).结论柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降,为一种钙离子通道阻滞剂(Calcium channel blocker, CCB),提示钙离子通道阻滞作用为柴胡逆转BEL-7402细胞多药耐药的机制之一.展开更多
目的:观察川芎嗪(L ig)对心肌细胞膜钙通道及胞内游离C a2+浓度([C a2+]i的影响,并探讨其作用机制。方法:急性分离大鼠心肌细胞,用特异性C a2+荧光探针F luo-3/AM负载细胞,激光共聚焦显微镜(LSCM)检测L ig作用后心肌细胞内[C a2+]i的变...目的:观察川芎嗪(L ig)对心肌细胞膜钙通道及胞内游离C a2+浓度([C a2+]i的影响,并探讨其作用机制。方法:急性分离大鼠心肌细胞,用特异性C a2+荧光探针F luo-3/AM负载细胞,激光共聚焦显微镜(LSCM)检测L ig作用后心肌细胞内[C a2+]i的变化。结果:L ig(30μm o l/L)可降低细胞内[C a2+]i;L-型钙通道阻断剂V erapam il(40μm o l/L)、1β受体特异阻断剂A teno lo l(900μm o l/L)和1α受体特异阻断剂Phen to lam ine(1×1-0 5m o l/L)预处理,均可不同程度地阻断L ig(30μm o l/L)对心肌细胞钙的作用;L ig(30μm o l/L)对1α受体特异激动剂Pheny lephrine(1×1-0 4m o l/L)、钙通道激动剂A 23187(900μm o l/L)和1β受体特异激动剂D obu tam ine(1×10-5m o l/L)引起的细胞内钙升高有抑制作用。不与血管紧张素Ⅱ的Ⅰ型受体(AT1R)阻断剂V a lsartan位点作用。结论:L ig对心肌细胞内[C a2+]i的降低作用,是由细胞膜上的L-型钙离子通道、1α受体和1β受体介导的。展开更多
文摘To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.
文摘目的:观察川芎嗪(L ig)对心肌细胞膜钙通道及胞内游离C a2+浓度([C a2+]i的影响,并探讨其作用机制。方法:急性分离大鼠心肌细胞,用特异性C a2+荧光探针F luo-3/AM负载细胞,激光共聚焦显微镜(LSCM)检测L ig作用后心肌细胞内[C a2+]i的变化。结果:L ig(30μm o l/L)可降低细胞内[C a2+]i;L-型钙通道阻断剂V erapam il(40μm o l/L)、1β受体特异阻断剂A teno lo l(900μm o l/L)和1α受体特异阻断剂Phen to lam ine(1×1-0 5m o l/L)预处理,均可不同程度地阻断L ig(30μm o l/L)对心肌细胞钙的作用;L ig(30μm o l/L)对1α受体特异激动剂Pheny lephrine(1×1-0 4m o l/L)、钙通道激动剂A 23187(900μm o l/L)和1β受体特异激动剂D obu tam ine(1×10-5m o l/L)引起的细胞内钙升高有抑制作用。不与血管紧张素Ⅱ的Ⅰ型受体(AT1R)阻断剂V a lsartan位点作用。结论:L ig对心肌细胞内[C a2+]i的降低作用,是由细胞膜上的L-型钙离子通道、1α受体和1β受体介导的。