The release of H-3-1-methyl-4-phenylpyridinium from bovine adrenal chromaffin cells is modulated by somatostatin

• Type: Article in International Scientific Journal
• Date: 2006

Authors

ribeiro, l (Author) FMUP; Martel, F (Author) FMUP; Azevedo, I (Author) Other

Journal

Title: Regulatory Peptides

Vol. 137

Pages: 107-113

ISSN: 0167-0115

Publisher: Elsevier B.V.

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Other information

Authenticus ID: P-004-FH1

DOI: 10.1016/j.regpep.2006.06.002

Abstract (EN): Besides cholinergic regulation, catecholamine secretion from adrenal chromaffin cells can be elicited and/or modulated by noncholinergic neurotransmitters and hormones. This study was undertaken to investigate the influence of somatostatin and octreotide on [H-3]MPP+ secretion evoked by KCl or cholinergic agents, from bovine adrenal chrornaffin cells. The release of[H-3]MPP+ was markedly increased by excess KCl (50 mM), acetylcholine (50 mu M - 10 mM) and by the nicotinic agonists, nicotine (5-100 mu M) and 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP, 10 - 100 mu M), but not by the muscarinic agonist, pilocarpine (10 - 100 mu M). Acetylcholine-evoked release of [H-3]MPP+ from these cells was mainly mediated by nicotinic receptors: a) nicotine and DMPP stimulated the release of [H-3]MPP+, b) a nicotinic antagonist, hexamethonium, markedly blocked the acetylcholine-evoked response and c) pilocarpine was devoid of effect on [H-3]MPP+ secretion. At all concentrations tested, somatostatin and octreotide interfered neither with [H-3]MPP+ basal release nor with KCl of induced release [H-3]MPP+. However, somatostatin (0.01 - 0.3 mu M) increased the release [H-3]MPP+ induced by a high concentration of acetylcholine (10 mM). Octreotide (1 - 10 mu M) had no effect. These results, showing that sornatostatin potentiates acetylcholine-induced [H-3]MPP+ release, support the hypothesis that somatostatin may increase the release of catecholamines from adrenal medullary cells.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7