as changes in effective vascular compliance) in dogs (n=12) during long-term nitroglycerin treatment (1.5 ,g/kg/min i.v. for 5-6 days). In dogs with nitroglycerin-specific tolerance (shift of venous or epicardial artery dilation to 15-17-fold higher dosages), N-acetylcysteine (100 mg/ kg i.v.) had no dilator effect and did not alter the dose-response relations of nitroglycerin. Yet, in nontoler...