Angiotensin II infusion restores stimulated angiogenesis in the skeletal muscle of rats on a high-salt diet

Am J Physiol Heart Circ Physiol. 2006 Jul;291(1):H114-20. doi: 10.1152/ajpheart.01116.2005. Epub 2006 Feb 3.

Abstract

Elevated dietary salt intake has previously been demonstrated to have dramatic effects on microvascular structure and function. The purpose of this study was to determine whether a high-salt diet modulates physiological angiogenesis in skeletal muscle. Male Sprague-Dawley rats were placed on a control diet (0.4% NaCl by weight) or a high-salt diet (4.0% NaCl) before implantation of a chronic electrical stimulator. After seven consecutive days of unilateral hindlimb muscle stimulation, animals on control diets demonstrated a significant increase in microvessel density in the tibialis anterior muscle of the stimulated hindlimb relative to the contralateral control leg. High salt-fed rats demonstrated a complete inhibition of this angiogenic response, as well as a significant reduction in plasma ANG II levels compared with those of control animals. To investigate the role of ANG II suppression on the inhibitory effect of high-salt diets, a group of rats that were fed high salt were chronically infused with ANG II at a low dose. Maintenance of ANG II levels restored stimulated angiogenesis to control levels in animals fed a high-salt diet. Western blot analysis indicated that inhibition of angiogenesis in high salt-fed rats was not due to changes in VEGF or VEGF receptor type 1 protein expression in response to stimulation; however, the degree to which VEGF receptor 2 protein increased with stimulation was significantly lower in high salt-fed animals. This study demonstrates an inhibitory effect of high salt intake on stimulated angiogenesis and suggests a critical role for ANG II suppression in mediating this antiangiogenic effect.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Angiogenesis Inducing Agents / administration & dosage
  • Angiogenesis Inhibitors / administration & dosage
  • Angiotensin II / administration & dosage*
  • Animals
  • Dose-Response Relationship, Drug
  • Drug Combinations
  • Male
  • Muscle, Skeletal / blood supply*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / metabolism*
  • Neovascularization, Physiologic / drug effects*
  • Neovascularization, Physiologic / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Sodium Chloride, Dietary / administration & dosage*

Substances

  • Angiogenesis Inducing Agents
  • Angiogenesis Inhibitors
  • Drug Combinations
  • Sodium Chloride, Dietary
  • Angiotensin II