ABSTRACT
Aim To evaluate the effects of notoginsen-oside R1 on store-operated calcium entry ( SOCE ) in pulmonary arterial smooth muscle cells ( PASMCs ) of chronic hypoxia ( CH)-and monocrotaline ( MCT)-in-duced pulmonary hypertension ( PH) rats. Methods Mn2+ quenching of Fura-2 and measurement of intra-cellular free calcium concentration ( [ Ca2+] i ) using fluo-3 were examined in PASMCs of CH-exposed and MCT-treated rats. Results ①CH-exposed and MCT-treated rats exhibited profound PH when examined 3 weeks after hypoxia exposure or MCT injection, respec-tively. ②In the presence of 3 μmol·L-1 nifedipine, 10 μmol · L-1 notoginsenoside R1 significantly re-duced cyclopiazonic acid ( CPA )-induced the percent reduction in Fura-2 fluorescence measured 500 sec af-ter application of Mn2+, the maximal rate of Mn2+quenching, the amplitude of the Ca2+ influx transient and the resting [ Ca2+] i in PASMCs of CH-exposed and MCT-treated rats. Conclusion Notoginsenoside R1 inhibits SOCE and reduces resting [ Ca2+] i in PASMCs of CH-and MCT-induced PH rats.