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 mere treated,vith 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.