Hydralazine dilates large epicardial coronary arteries in conscious dogs through an endothelium-independent mechanism

J Cardiovasc Pharmacol. 1994 Feb;23(2):315-8.

Abstract

In chronically instrumented conscious dogs, hydralazine (30-300 micrograms/kg) and nitroglycerin (NTG 0.03-10 micrograms/kg) dose-dependently dilated large epicardial coronary arteries. Simultaneously, hydralazine also dose-dependently dilated small coronary arteries, whereas a similar effect was observed only after NTG > 0.3 microgram/kg. When large coronary arteries were deendothelialized by a balloon angioplasty catheter, dilation of large coronary arteries in response to acetylcholine (ACh 0.3 microgram/kg) and to reactive hyperemia was reduced by 87 and 95%, respectively. In contrast, vasodilation of large coronary arteries induced by hydralazine and NTG was only minimally and similarly affected (-19% for both drugs). These findings demonstrate that in vivo hydralazine-induced dilation of large coronary arteries is endothelium independent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angioplasty, Balloon
  • Animals
  • Coronary Circulation / drug effects
  • Coronary Vessels / anatomy & histology
  • Coronary Vessels / drug effects*
  • Dogs
  • Dose-Response Relationship, Drug
  • Endothelium, Vascular / physiology*
  • Hydralazine / pharmacology*
  • Nitroglycerin / pharmacology
  • Vasodilator Agents / pharmacology*

Substances

  • Vasodilator Agents
  • Hydralazine
  • Nitroglycerin