Enhancers of cytosolic cAMP augment depolarization-induced exocytosis from pancreatic B-cells: evidence for effects distal to Ca2+ entry
KD Gillis, S Misler - Pflügers Archiv, 1993 - Springer
KD Gillis, S Misler
Pflügers Archiv, 1993•SpringerWe have investigated the effects of cAMP enhancing agents on depolarization-induced
membrane capacitance increases (ΔC m in single rat pancreatic B-cells. Concentrations of
IBMX, 8-CPT cAMP and forskolin, which enhance cAMP and insulin release, all enhance
depolarization-induced ΔC m's seen in response to single voltage-clamp pulses and reduce
the depression of ΔC m responses often seen with trains of pulses. These effects often occur
in the absence of changes in peak Ca 2+ current or the total Ca 2+ charge entry during the …
membrane capacitance increases (ΔC m in single rat pancreatic B-cells. Concentrations of
IBMX, 8-CPT cAMP and forskolin, which enhance cAMP and insulin release, all enhance
depolarization-induced ΔC m's seen in response to single voltage-clamp pulses and reduce
the depression of ΔC m responses often seen with trains of pulses. These effects often occur
in the absence of changes in peak Ca 2+ current or the total Ca 2+ charge entry during the …
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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