Abstract
We have previously shown that whole-body nitric oxide (NO) production in patients with essential hypertension is significantly diminished compared to healthy controls. The aim of the present study was to determine whether treatment with anti-hypertensive therapy increases whole-body NO production in hypertensive patients using L-[15N]2-arginine as a metabolic tracer.
Sixty patients with essential hypertension participated in the study. After a two week wash-out period of previous antihypertensive medications, patients were randomised to receive either quinapril or losartan for six months. Patients were studied at baseline (after washout), 4 weeks and 20 weeks of treatment. Following a single intravenous bolus administration of L-[15N]2 arginine, 12-hour ambulatory blood pressure monitoring and complete urine collections were assessed in both treatment groups. Urinary 15N/14N nitrate ratio was determined by dry combustion in an isotope ratio mass spectrometer.
Mean 12-hour systolic and diastolic blood pressures lowered significantly during the study but there were no significant differences between the treatment groups. Neither quinapril nor losartan altered NO production significantly and there were no significant treatment differences between the groups. However, whole body NO production was significantly higher in hypertensive post-menopausal women than hypertensive men (P = 0.039).
The present data show that hypotensive effects of quinapril and losartan do not appear to be correlated with increased NO production; however their pharmacological effects on NO bioavailability could not be ruled out in this study.
Sixty patients with essential hypertension participated in the study. After a two week wash-out period of previous antihypertensive medications, patients were randomised to receive either quinapril or losartan for six months. Patients were studied at baseline (after washout), 4 weeks and 20 weeks of treatment. Following a single intravenous bolus administration of L-[15N]2 arginine, 12-hour ambulatory blood pressure monitoring and complete urine collections were assessed in both treatment groups. Urinary 15N/14N nitrate ratio was determined by dry combustion in an isotope ratio mass spectrometer.
Mean 12-hour systolic and diastolic blood pressures lowered significantly during the study but there were no significant differences between the treatment groups. Neither quinapril nor losartan altered NO production significantly and there were no significant treatment differences between the groups. However, whole body NO production was significantly higher in hypertensive post-menopausal women than hypertensive men (P = 0.039).
The present data show that hypotensive effects of quinapril and losartan do not appear to be correlated with increased NO production; however their pharmacological effects on NO bioavailability could not be ruled out in this study.
Original language | English |
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Pages (from-to) | 183A |
Number of pages | 1 |
Journal | American Journal of Hypertension |
Volume | 17 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2004 |
Bibliographical note
Am J Hypertens (2004) 17, 183A–183A; doi: 10.1016/j.amjhyper.2004.03.481Keywords
- nitric oxide
- hypertension
- antihypertensive drugs