title: Decreased angiotensin II response but unaltered cardiovascular pressor response to infused norepinephrine after sodium restriction and converting enzyme inhibition.
abstract: Although studies indicate that converting enzyme inhibitors such as captopril influence beta-adrenergic physiology, the data on alpha-adrenergic physiology is inconsistent. This study therefore examined the effects of captopril (50 mg/day for 5 days) during sodium restriction on the pressor response and on angiotensin II and neuropeptide Y levels to infused norepinephrine (0.01 to 0.1 micrograms/kg/min) in 17 hypertensive and 27 normotensive subjects. Angiotensin II increased significantly in response to infused norepinephrine during placebo administration (p < 0.001) but not during captopril administration (p = 0.15). Neuropeptide Y levels decreased in response to captopril (p = 0.02). Despite these changes the pressor response to infused norepinephrine was unchanged with captopril. These data support the conclusion that the antihypertensive action of captopril is unrelated to alterations in norepinephrine-mediated alpha-adrenergic pressor regulation. The finding of a decrease in neuropeptide Y levels may have relevance to the therapeutic effects of captopril.
authors: Department of Psychiatry, UCSD Medical Center, University of California 92093-0804.
authors: P J
authors: PJ
authors: Mills
authors: J E
authors: JE
authors: Dimsdale
authors: M G
authors: MG
authors: Ziegler
authors: R A
authors: RA
authors: Nelesen
authors: M R
authors: MR
authors: Brown
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000804:Angiotensin II / Q000097:blood*; D001794:Blood Pressure / Q000187:drug effects*; D002216:Captopril / Q000494:pharmacology*; D004039:Diet, Sodium-Restricted; D004311:Double-Blind Method; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009478:Neuropeptide Y / Q000097:blood; D009638:Norepinephrine / Q000494:pharmacology*
chemical_list: D009478:Neuropeptide Y; D000804:Angiotensin II; D002216:Captopril; D009638:Norepinephrine