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Agmatine: an endogenous clonidine-displacing substance in the brain

journal contribution
posted on 1994-02-18, 00:00 authored by G Li, S Regunathan, Colin BarrowColin Barrow, J Eshraghi, R Cooper, D J Reis
Clonidine, an antihypertensive drug, binds to alpha 2-adrenergic and imidazoline receptors. The endogenous ligand for imidazoline receptors may be a clonidine-displacing substance, a small molecule isolated from bovine brain. This clonidine-displacing substance was purified and determined by mass spectroscopy to be agmatine (decarboxylated arginine), heretofore not detected in brain. Agmatine binds to alpha 2-adrenergic and imidazoline receptors and stimulates release of catecholamines from adrenal chromaffin cells. Its biosynthetic enzyme, arginine decarboxylase, is present in brain. Agmatine, locally synthesized, is an endogenous agonist at imidazoline receptors, a noncatecholamine ligand at alpha 2-adrenergic receptors and may act as a neurotransmitter.

History

Journal

Science

Volume

263

Issue

5149

Pagination

966 - 969

Publisher

American Association for the Advancement of Science

Location

Washington, D.C.

ISSN

0036-8075

eISSN

1095-9203

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1994, American Association for the Advancement of Science