Effects of Inhibition of NO-Synthesis on Renal Hemodynamics and Sodium Excretion in Patients With Essential Hypertension and Healthy Controls

Phase 1 Study of the Effects of Systemic Nitric Oxide Inhibition With Ng-Monomethyl-L-Arginine on Renal Hemodynamics and Sodium Excretion in Patients With Essential Hypertension and Healthy Controls

The study tests the hypothesis that systemic and renal nitric oxide synthesis is changed in essential hypertension by investigating the effects of a non selective nitric oxide inhibitor on renal hemodynamics and sodium excretion in patients with essential hypertension. The results are compared with a group of healthy subjects.

The study investigates the effects of Ng-monomethyl-L-arginine (L-NMMA) on:

1. renal hemodynamics (renal plasma flow and glomerular filtration rate)
2. renal sodium excretion
3. lithium clearance and fractional lithium excretion
4. plasma levels of vasoactive hormones
5. blood pressure and heart rate

Inclusion Criteria:

• Essential hypertension (blood pressure > 140/90) with no signs of secondary hypertension
• P-creatinine < 200 µmol/L

Exclusion Criteria:

• Anamnestic or clinical signs of heart disease, renal disease, liver disease, neoplastic disease, anemia or cerebro-vascular insult
• Medication except antihypertensives
• Drug or alcohol abuse
• Pregnancy