Summary
We have investigated the effects of cAMP enhancing agents on depolarization-induced membrane capacitance increases (ΔCm in single rat pancreatic B-cells. Concentrations of IBMX, 8-CPT cAMP and forskolin, which enhance cAMP and insulin release, all enhance depolarization-induced ΔCm's seen in response to single voltage-clamp pulses and reduce the depression of ΔCm responses often seen with trains of pulses. These effects often occur in the absence of changes in peak Ca2+ current or the total Ca2+ charge entry during the depolarizing pulse. These data suggest that cAMP modulating maneuvers may directly affect the mechanism of insulin granule mobilization into a readily releasible store or fusion at a discharge site.
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Gillis, K.D., Misler, S. Enhancers of cytosolic cAMP augment depolarization-induced exocytosis from pancreatic B-cells: evidence for effects distal to Ca2+ entry. Pflugers Arch. 424, 195–197 (1993). https://doi.org/10.1007/BF00374612
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DOI: https://doi.org/10.1007/BF00374612