cAMP directly facilitates Ca-induced exocytosis in bovine lactotrophs |
| |
Authors: | S K Sikdar R Zorec W T Mason |
| |
Affiliation: | Department of Neuroendocrinology, AFRC Institute of Animal Physiology, Cambridge, UK. |
| |
Abstract: | We have used the whole cell patch clamp technique on single prolactin-secreting bovine lactotrophs to measure plasma membrane capacitance (Cm), an index of membrane surface area, under voltage-clamp during cytosol dialysis with Ca and cAMP. cAMP increased the magnitude and rate of Ca-induced exocytosis (Cm increase) without affecting membrane conductance; however, cAMP had no detectable effect on Cm when intracellular Ca was low. We thus report new evidence that cAMP can facilitate Ca-induced secretion in a synergistic fashion, by acting directly on the secretory apparatus, independently of membrane conductance activation. |
| |
Keywords: | |
|
|