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.

Primary cultures of bovine adrenal medullary chromaffin cells can be stimulated with nicotine, which mimics the cholinergic stimulus from the splanchnic nerve. Histamine also stimulates catecholamine release in a time- and dose-dependent manner. We have previously shown that nicotine stimulates incorporation of 32Pi into the vesicle-associated phosphoprotein synapsin II. We report here that histamine, too, stimulates an increase in 32Pi incorporation into synapsin II, which is blocked by the H1-histamine receptor-specific antagonist pyrilamine. The time course of histamine-stimulated synapsin II phosphorylation closely paralleled that of histamine-stimulated catecholamine release. Interestingly, histamine and nicotine produced an additive increase in both catecholamine release and synapsin II phosphorylation, suggesting that these two secretogogues stimulate the phenomena via independent mechanisms. When we investigated the dependence of these two agonists on extracellular calcium, we found that nicotine-stimulated release and synapsin II phosphorylation were reduced to basal levels at low calcium concentrations. However, the histamine-stimulated effects remained significantly elevated. This suggests that calcium arising from two separate pools can stimulate catecholamine release and synapsin II phosphorylation in bovine chromaffin cells. Taken together, these data support the hypothesis that synapsin II phosphorylation is a component of the secretory response from these cells.

Type

Journal article

Journal

J Neurochem

Publication Date

02/1992

Volume

58

Pages

441 - 447

Keywords

Adrenal Glands, Animals, Calcium, Cattle, Chromaffin System, Extracellular Space, Histamine, Nicotine, Norepinephrine, Osmolar Concentration, Phosphorylation, Synapsins