Conformational changes induced in voltage-gated calcium channel Cav1.2 by BayK 8644 or FPL64176 modify the kinetics of secretion independently of Ca2+ influx.

ABSTRACT: The role of the L-type calcium channel (Cav1.2) as a molecular switch that triggers secretion prior to Ca(2+) transport has previously been demonstrated in bovine chromaffin cells and rat pancreatic beta cells. Here, we examined the effect of specific Cav1.2 allosteric modulators, BayK 8644 (BayK) and FPL64176 (FPL), on the kinetics of catecholamine release, as monitored by amperometry in single bovine chromaffin cells. We show that 2 microm BayK or 0.5 microm FPL accelerates the rate of catecholamine secretion to a similar extent in the presence either of the permeable Ca(2+) and Ba(2+) or the impermeable charge carrier La(3+). These results suggest that structural rearrangements generated through the binding of BayK or FPL, by altering the channel activity, could affect depolarization-ev

SUBMITTER: Marom M 

PROVIDER: S-EPMC2844149 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature