Effects of several Chinese crude drugs on 45Ca transmembrane influx in vascular smooth muscles

The effects of several Chinese crude druge including Crocus sativus,Carthamus tinctorius and Ginkgo biloba on Ca^2+ transmembrane influx in rat aorta rings were studied.Resting 45Ca uptake was not markedly altered by these drugs,whereas the 45 Ca influxes evoked by norepinephrine(1.2umol/L)and KCl(100mmol/L) in rat aorta rings were significantly inhibited by Crocus and Carthamus in a concentration-dependent manner,not by Ginkgo.The results indicate that extracellular Ca^2+ tansmembrane influx through receptor-operated Ca^2+ channels and potential-dependent Ca^2+ channels can be blocked by crocus and Carthamus.