Abstract This study was performed to test the hypothesisthat endothelin peptides differentially influence intracellularcalcium concentration([Ca^(2+)]i) in preglomerular microvascu-lar smooth muscle cells (MVSMC),in p...Abstract This study was performed to test the hypothesisthat endothelin peptides differentially influence intracellularcalcium concentration([Ca^(2+)]i) in preglomerular microvascu-lar smooth muscle cells (MVSMC),in part through activationof endothelin (ET) A receptors.Experiments were performedin vitro with the use of single MVSMC freshly isolated fromrat preglomerular microvessels.The effect of ET-1,ET-2,and ET-3 on[Ca^(2+)]i was measured with the use of the calci-um-sensitive dye, fura 2, and standard fluorescence mi-croscopy techniques. Baseline [Ca^(2+)]i averaged (84±3)nmol/L (n=141 cells from 23 dispersions). ET-1 concentra-tions of 1,10,and 100 nmol/L evoked peak increases in[Ca^(2+)]i of(48±16),(930±125),and (810±130)nmol/L,respectively.The time course of the [Ca^(2+)]i response wasbiphasic,beginning with a rapid initial increase followed by asustained plateau phase or a period during which [Ca^(2+)]i os-cillated sharply.Similar responses were observed after ET-2administration.In contrast。展开更多
文摘Abstract This study was performed to test the hypothesisthat endothelin peptides differentially influence intracellularcalcium concentration([Ca^(2+)]i) in preglomerular microvascu-lar smooth muscle cells (MVSMC),in part through activationof endothelin (ET) A receptors.Experiments were performedin vitro with the use of single MVSMC freshly isolated fromrat preglomerular microvessels.The effect of ET-1,ET-2,and ET-3 on[Ca^(2+)]i was measured with the use of the calci-um-sensitive dye, fura 2, and standard fluorescence mi-croscopy techniques. Baseline [Ca^(2+)]i averaged (84±3)nmol/L (n=141 cells from 23 dispersions). ET-1 concentra-tions of 1,10,and 100 nmol/L evoked peak increases in[Ca^(2+)]i of(48±16),(930±125),and (810±130)nmol/L,respectively.The time course of the [Ca^(2+)]i response wasbiphasic,beginning with a rapid initial increase followed by asustained plateau phase or a period during which [Ca^(2+)]i os-cillated sharply.Similar responses were observed after ET-2administration.In contrast。
