to evaluate possible mechanisms underlying the development of nitrate tolerance , we treated 35 patients who had severe chronic heart failure with a prolonged ( 48-hour ) intravenous infusion of nitroglycerin ( 6.4 micrograms per kilogram of body weight per minute ) given either continuously or intermittently ( 12-hour infusions separated by intervals of 12 hours ) .
C0028125
nitrate
C0017887
nitroglycerin