The effects of removal of endothelium and changes in blood flow in conscious dogs on the responses of large iliac artery diameter to local infusion of nitroglycerin, acetylcholine, epinephrine, and norepinephrine into the iliac artery were studied. Infusion of agonists did not change mean arterial pressure or heart rate. In vessels with intact endothelium, iliac diameter increased with nitrogly...

We have evaluated the haemodynamic effects of intravenous (iv) nitroglycerin (NG) and vasopressin (VP) alone and in combination, in 12 patients with cirrhosis and recent variceal haemorrhage (two to seven days). Nitroglycerin infusion alone (200 micrograms/min) produced a significant fall in portal pressure (WHVP-FHVP) (from 16.4 (0.6) to 13.3 (1.2) mmHg; p less than .001) associated with hypot...

The long-term benefits of nitroglycerin therapy are limited by tolerance development. Understanding the precise nature of mechanisms underlying nitroglycerin-induced endothelial cell dysfunction may provide new strategies to prevent tolerance development. In this line, we tested interventions to prevent endothelial dysfunction in the setting of nitrate tolerance. When bovine aortic endothelial ...

In order to investigate the direct metabolic effect of nitroglycerin on myocardium, its effect on mitochondrial free radical formation was studied in vitro, using the dog heart mitochondria impaired by ethanol. Free radical concentrations in state 4 respiration or the ratio of free radical concentrations in state 4 to state 1 was used as an index of mitochondrial function. Free radical concentr...

Previous studies have suggested that (1) nitroglycerin causes vasodilatation by interacting with sulfhydryl groups in vascular smooth muscle, thereby activating guanylate cyclase and increasing the intracellular concentration of cyclic GMP, and (2) N-acetylcysteine, a source of sulfhydryl groups, potentiates the peripheral vasodilatory effect of nitroglycerin. This study was performed to explor...

The radioactive microsphere technique was used to trace regional blood flow and total cardiac output distribution in rats in heart failure secondary to biventricular volume overload during acute intravenous infusion of nitroglycerin. Data from rats with heart failure (chronic arteriovenous shunt) were compared to data obtained from rats subjected to sham surgical procedures. In both glycerin an...

Intravenous nitroglycerin would appear to be an ideal agent for the treatment of severe pregnancy-induced hypertension complicated by cardiogenic pulmonary edema. Nitroglycerin infusion effectively reduces preload by venous dilatation and, at higher doses, results in arterial vasodilatation. Because of these pharmacologic properties, the effects of intravenous nitroglycerin were studied in thre...

Iloprost is a prostacyclin analogue mainly used in the treatment of pulmonary hypertension. It is also effective for renal dysfunction during renal transplant and coronary artery bypass grafting surgery, but there have been few comparative experimental studies with iloprost. We aimed to compare vasorelaxant properties of iloprost, with those of diltiazem, nitroglycerin and papaverine on rat tho...

Clinical studies have suggested that long-term nitrate treatment does not improve and may even worsen cardiovascular mortality, and the possible role of nitrate tolerance has been suspected. Nitrate tolerance has been recently shown to increase vascular superoxide and peroxynitrite production leading to vascular dysfunction. Nevertheless, nitrates exert direct cardiac effects independent from t...

coronary arteries, -4 or that they diminish the oxygen requirements of the myocardium by diminishing the external work of the heart.5'6 Much of the confusion concerning the actions of these drugs has arisen from the assumption that nitroglycerin and amyl nitrite have similar effects. Moreover, many studies on the peripheral circulatory effects of nitrites have been carried out with sodium nitri...