The nitric oxide system and cortisol-induced hypertension in humans.
1. The aim of the present study was to assess the role of the nitric oxide (NO) system in cortisol-induced hypertension in humans. 2. Plasma and urinary nitrate/nitrite concentrations and plasma concentrations of arginine and symmetric (SDMA) and asymmetric (ADMA) dimethyl arginine were measured in six subjects on a restricted nitrate diet who were treated with 80 mg/day cortisol and in subjects on an unrestricted nitrate diet who were treated with cortisol (80 mg/day, n = 6, or 200 mg/day, n = 10) for 5 days. 3. Cortisol significantly increased systolic and mean arterial pressure. Significant reductions in plasma nitrate/nitrite concentrations were observed in subjects on a restricted nitrate diet on days 3, 4 and 5 of cortisol treatment (to 11 +/- 1, 10 +/- 1, 11 +/- 1 pmol/L, respectively) compared with pretreatment (16 +/- 1 pmol/L; P < 0.01). There were no significant changes in plasma arginine, ADMA or SDMA concentrations. 4. Cortisol treatment significantly increased blood pressure and reduced plasma nitrate/nitrite concentrations. Reductions in plasma nitrate concentrations are not explained by changes in substrate availability or in endogenous nitric oxide synthase inhibitors. These data support a role for the NO system in cortisol-induced hypertension in humans.
Kelly
J J
JJ
Department of Medicine, University of New South Wales, St George Hospital, Kogarah, Australia. jkelly@s056.aone.net.au
Tam
S H
SH
Williamson
P M
PM
Lawson
J
J
Whitworth
J A
JA
D001120:Arginine / Q000031:analogs & derivatives / Q000097:blood / Q000652:urine; D006801:Humans; D006854:Hydrocortisone; D006973:Hypertension / Q000097:blood / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D009566:Nitrates / Q000097:blood / Q000652:urine; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009573:Nitrites / Q000097:blood / Q000652:urine
D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D006854:Hydrocortisone