Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Neurotransmitters and hormones such as somatostatin, galanin, and adrenalin reduce insulin secretion. Their inhibitory action involves direct interference with the exocytotic machinery. We have examined the molecular processes underlying this effect using high resolution measurements of cell capacitance. Suppression of exocytosis was maximal at concentrations that did not cause complete inhibition of glucose-stimulated electrical activity. This action was dependent on activation of G proteins but was not associated with inhibition of the voltage-dependent Ca2+ currents or adenylate cyclase activity. The molecular processes initiated by the agonists culminate in the activation of the Ca(2+)-dependent protein phosphatase calcineurin, and suppression of the activity of this enzyme abolishes their action on exocytosis. We propose that mechanisms similar to those we report here may contribute to adrenergic and peptidergic inhibition of secretion in other neuroendocrine cells and in nerve terminals.

Type

Journal article

Journal

Neuron

Publication Date

09/1996

Volume

17

Pages

513 - 522

Keywords

Adrenergic Agonists, Animals, Calcineurin, Calcium, Calmodulin-Binding Proteins, Cells, Cultured, Clonidine, Cytoplasm, Electrophysiology, Enzyme Activation, Epinephrine, Exocytosis, GTP-Binding Proteins, Galanin, Guanine, Hormone Antagonists, Insecticides, Insulin, Islets of Langerhans, Mice, Mice, Inbred Strains, Neurotransmitter Agents, Nitriles, Phosphoprotein Phosphatases, Pyrethrins, Somatostatin