Potassium Ion Release and Enzyme Secretion: Adrenergic Regulation by α-and β-Receptors

Abstract

Epinephrine caused amylase secretion and K⁺ release in rat parotid slices. Propranolol, which blocks β-receptors, inhibited amylase secretion; phentolamine, which blocks α-receptors, inhibited K⁺ release. Since enzyme secretion was associated with fusion of secretory granules to the cell membrane and K⁺ release was associated with vacuole formation, it could be shown that both α- and β-receptors are present in the same exocrine cell. The findings appear to exclude cyclic 3',5'-adenosine monophosphate as an intermediate in the α-receptor response.