Effects of S-nitrosocaptopril on cyclopiazonic acid-induced [Ca~(2+) ]_i change in rat aortic smooth muscle cells / 中国药理学通报

ABSTRACT

AIM To study the characteristics of Ca 2+ channel mediated store operated Ca 2+ influx on rat vascular smooth muscle. METHOD Fura 2 fluorescence technique was used to investigate the [Ca 2+ ] i change. RESULTS ① S nitrosocaptopril (CapNO,20～120 ?mol?L -1 ) produced a concentration dependent inhibitory effect on cyclopiazonic acid(CPA) induced [Ca 2+ ] i change. The maximal inhibitory effect(37%?17%) of CapNO was reached at a concentration of 80 ?mol?L -1 . The same concentration of Captopril had no effects. ② Inhibition rate of 80 ?mol?L -1 CapNO (The concentration of maximal effect, CME) on CPA induced [Ca 2+ ] i change was 30%?10%, subsequent addition of 1 ?mol?L -1 Nif (CME)did not further produced the decrease effect (54%?18%). subsequent addition of 20 ?mol?L -1 SK&F96365 (CME) further produced the decrease effect. The inhibitory effects of 20 ?mol?L -1 SK&F96365 were significantly different in the cases of CapNO and Nif pretreatment(24%?10%) and non treatment (54%?11%). ③ The inhibitory effects of 2 ?mol?L -1 tyrphostinAG490(AG490,CME) were significantly different in the cases of CapNO (CME) pretreatment (24%?9%)and non treatment (42%?10%). 80 ?mol?L -1 CapNO effect on CPA induced [Ca 2+ ] i changes in AG490 pretreatment condition(18%?7%) was different from that in non treatment case(37%?10%). CONCLUSION S nitrosocaptopril obviously inhibits the opening of SOCC and VDCC, which mediates store operated Ca 2+ influx. The inhibitory effects of CapNO is associated with both sensitive to and non sensitive to tyrosine kinase (Janus2).