Oral L-arginine improves endothelial dysfunction in patients with essential hypertension

Int J Cardiol. 2002 Dec;86(2-3):317-23. doi: 10.1016/s0167-5273(02)00413-8.


Background: L-Arginine is a nitric oxide precursor, which augments endothelium-dependent vasodilatation in hypercholesterolemic humans and animals. Endothelium-dependent vasodilation is attenuated in patients with hypertension; however the effects of oral L-arginine on endothelial function of the conduit arteries in patients with essential hypertension have not previously been investigated.

Methods: In a prospective randomized double blind trial, 35 patients with essential hypertension received either 6 g L-arginine (18 subjects) or placebo (17 subjects). Patients were examined for flow-mediated endothelium-dependent dilatation of the brachial artery before and 1.5 h after administration of L-arginine or placebo. At the end of the protocol the nitrate-induced, endothelium-independent vasodilatation was evaluated.

Results: Two groups of L-arginine and placebo were similar regarding age, sex, blood lipids, smoking, diabetes, coronary artery disease, body mass index, intima-media thickness of the common carotid artery, clinics blood pressure and baseline brachial artery parameters. Administration of L-arginine or placebo did not change significantly heart rate, blood pressure, baseline diameter, blood flow or reactive hyperemia. L-Arginine resulted in a significant improvement of flow-mediated dilatation (1.7+/-3.4 vs. 5.9+/-5.4%, P=0.008) while placebo did not significantly change this parameter (3.0+/-2.7 vs. 3.1+/-2.2%, P=ns). The effect of L-arginine on flow-mediated dilatation was significantly different from the effect of placebo (P=0.05). L-Arginine did not significantly influence nitrate-induced dilatation (16+/-6.9 vs. 17.7+/-6.7%, P=ns).

Conclusions: Oral administration of L-arginine acutely improves endothelium-dependent, flow-mediated dilatation of the brachial artery in patients with essential hypertension. The long-term effects of L-arginine in these patients require further investigation.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Arginine / administration & dosage*
  • Arginine / therapeutic use*
  • Brachial Artery / diagnostic imaging
  • Brachial Artery / drug effects
  • Brachial Artery / physiopathology
  • Double-Blind Method
  • Endothelium, Vascular / diagnostic imaging
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / physiopathology*
  • Female
  • Hemodynamics / drug effects
  • Hemodynamics / physiology
  • Humans
  • Hypertension / diagnostic imaging
  • Hypertension / drug therapy*
  • Hypertension / physiopathology*
  • Male
  • Middle Aged
  • Prospective Studies
  • Ultrasonography


  • Arginine