The Involvement of Ser1898 of the Human L-Type Calcium Channel in Evoked Secretion
Figure 5
The effect of forskolin on GFP-infected chromaffin cells. Amperometry currents were elicited by a 10 sec puff of 60 mM KCl (K60) in GFP-infected cells in the presence of 1 μM forskolin, as indicated by the arrow. (a) Representative single amperometric events of GFP-infected cells with () or without forskolin (). (b) The cumulative number of events per cell averaged for GFP-infected cells with or without forskolin was plotted versus time (left). An expanded view of the initial cumulative spike counts plotted versus time (right). (c) The initial rate of secretion calculated from the linearization of the cumulative averaged spike count (left). Means were calculated for individual cells as an average of more than 500 spikes; see Table 1. The total amount of catecholamine secreted was quantified by averaging of the total mean charge. Summation of spike areas in cells infected with GFP during time range of 10–40 sec, which includes the 10 sec K60 stimulation and a 20 sec poststimulus period (right); *.
