Effects of Cl~-channels blockers on Ca~(2+) influx induced by ?_1-adrenoceptor subtypes / 中国药理学通报

ABSTRACT

AIM To investigate the roles of Cl- channels in Ca2+ influx induced by activaion of al- adrenoceptor subtypes in transfected-CHO cells. METHODS The effects of drugs on ?1A、?1B and ?1D- AR-induced Ca2+ influx were investigated with Fura2 fluorescence technique. RESULTS The ?1A-AR- induced Ca2+ influx was inhibited by furosemide(2 .5 ~ 10 M?mol?L- 1 )and SK&F96365(5- 15 ?mol?L- 1 ) in a concentration- dependent manner respectively; The ?1B-AR-induced Ca2+ influx could also be inhibit inhibited by NFA(2. 5 ~ 10 ?mol? L-1 ), whereas the alD AR-induced Ca2+ influx was only suppressed by NFA. In ?1B-CHO cells, Adr-triggered Ca2+ influx could be further inhibited by NFA or furosemide after the maximal inhibition by SK&F96365;SK&F96365 could further inhibit Ca2+ influx which had been inhibited by NFA or furosemide. In ?1A-CHO cells, Adr-triggered Ca2+ influx could be further inhibited by SK&F96365 after had been inhibited by furosemide; furosemide could not further inhibite Ca2+ influx which had been inhibited by S&F96365. CONCLUSION There are different characteristics of CI- channels related to ?1A、 ?1B and ?1D-AR-induced Ca2+ influx.