Effect of urapidil on rat brain catecholamine synthesis
Pugsley, T.A.; Myers, S.
Journal of Pharmacy and Pharmacology 38(9): 689-691
1986
ISSN/ISBN: 0022-3573 PMID: 2877070 Document Number: 280154
The effects of urapidil, a clinically effective antihypertensive drug, on the in-vivo rate of synthesis of rat brain noradrenaline (NA) and dopamine (DA) was determined. A significant dose-dependent increase in dopa concentration by urapidil after dopa decarboxylase inhibition by NSD 1015 was observed in brain stem (3-30 mg kg-1 i.p.) and striatum (10-30 mg kg-1 i.p.), indicating increased NA and DA turnover, respectively, most probably a result of central blockade of brainstem .alpha.1-adrenergic and striatal DA receptors. These results indicate that urapidil may possibly exert its central hypotensive action in part by a reduced influence on brain stem NA, thus reducing central sympathetic outflow.