Effects of(1R,9S)-beta-Hydrastine on Intracellular Calcium Concentration in PC12 Cells

摘要

(1R,9S)-beta-Hydrastine(BHS)decreases the basal intracellular Ca~(2+)concentration([Ca~(2+)]_i)in PC12 cells.~(5))This study examined the effects of(1R,9S)-BHS on [Ca~(2+)]_i in PC12 cells.(1R,9S)-BHS at 10-100 flu in combination with a high extracellular K~+ level(56 mM)inhibited the release of dopamine in a concentration-dependent manner with an IC_(50)value of 66.5mu M.BHS at 100 mu M inhibited the sustained increase in [Ca~(2+)]_i induced by a high K~+ level(56 m M),and had an inhibitory effect on the 2 mu M nifedipine-induced blockage of the K~+-stimulated sustained increase in [Ca~(2+)]_i.In addition,(1R,9S)-BHS at 100 mu M prevented the rapid and sustained increase in [Ca~(2+)]_i elicited by 20 mM caffeine,but did not have an effect on the increase induced by 1 mu M thapsigargin,in the presence of external Ca~(2+).These results suggest that the active sites of(1R,9S)-BHS are mainly L-type Ca~(2+)channels and caffeine-sensitive Ca~(2+)-permeable channels in PC12 cells.