Effects of L-arginine on impaired acetylcholine-induced and ischemic vasodilation of the forearm in patients with heart failure

Circulation. 1994 Aug;90(2):658-68. doi: 10.1161/01.cir.90.2.658.

Abstract

Background: Endothelium-dependent vasodilation in response to acetylcholine (ACh) and ischemic vasodilation during reactive hyperemia are attenuated in the forearm of patients with heart failure (HF). It has been shown that L-arginine augments endothelium-dependent vasodilation in healthy subjects. Thus, the aim of the present study was to determine if L-arginine improves endothelium-dependent and ischemic vasodilation in the forearm in HF.

Methods and results: Forearm blood flow was measured by a strain-gauge plethysmograph in 20 patients with HF and in 24 age-matched control subjects (C). Resting forearm vascular resistance (FVR) was significantly higher in HF than in C (37 +/- 4 versus 22 +/- 2 U, P < .01). Intra-arterial infusions of ACh or sodium nitroprusside (SNP) at graded doses progressively decreased FVR in HF as well as in C. The magnitude of ACh-induced vasodilation was attenuated in HF (P < .01), whereas SNP-induced vasodilation was similar between the two groups. The minimal FVR during reactive hyperemia after 10 minutes of arterial occlusion was significantly higher in HF (n = 12) than in C (n = 12) (3.2 +/- 0.4 versus 2.1 +/- 0.1 U, P < .05). L-Arginine significantly augmented maximal vasodilation evoked with ACh and decreased minimal FVR during reactive hyperemia in HF (P < .01) but not in C. L-Arginine did not affect SNP-induced vasodilation in HF or C.

Conclusions: Our results suggest that defective endothelial function may contribute to impaired ischemic vasodilator capacity in HF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / pharmacology
  • Arginine / pharmacology*
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / physiology*
  • Female
  • Forearm / blood supply*
  • Heart Failure / physiopathology*
  • Humans
  • Hyperemia / physiopathology
  • Male
  • Middle Aged
  • Nitric Oxide / physiology*
  • Nitroprusside / pharmacology
  • Plethysmography
  • Vascular Resistance / drug effects
  • Vasodilation / drug effects*
  • Vasodilation / physiology

Substances

  • Nitroprusside
  • Nitric Oxide
  • Arginine
  • Acetylcholine