Depletion of intracellular calcium stores by agonist stimulation is coupled to calcium influx across the plasma membrane, a process termed capacitative calcium entry. Capacitative calcium entry was examined in cultured guinea pig enteric glial cells exposed to endothelin 3. Endothelin 3 (10 n M ) caused mobilization of intracellular calcium stores followed by influx of extracellular calcium. This capacitative calcium influx was inhibited by Ni 2+ (89 ± 2%) and by La 3+ (78 ± 2%) but was not affected by L-, N-, or P-type calcium channel blockers. Chelerythrine, a specific antagonist of protein kinase C, dose-dependently inhibited capacitative calcium entry. The nitric oxide synthase inhibitor N G -nitro-l-arginine decreased calcium influx in a dose-dependent manner. The combination of chelerythrine and N G -nitro-l-arginine produced synergistic inhibitory effects. Capacitative calcium entry occurs in enteric glial cells via lanthanum-inhibitable channels through a process regulated by protein kinase C and nitric oxide.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65161/1/j.1471-4159.1998.71010205.x.pd
