An important component of the antianginal efficacy of glyceryl trinitrate (GTN) is attributable to its selective venodilator effect, resulting in decreased cardiac preload and myocardial oxygen demand. Tolerance to nitrates occurs during chronic exposure, and the current study assessed whether this was due to increased phosphodiesterase (PDE) activity in the venous circulation. Tolerance was in...

BACKGROUND An hCG regression curve has been used to predict the natural history and response to chemotherapy in gestational trophoblastic disease. We constructed hCG regression curves in high-risk gestational trophoblastic neoplasia (GTN) treated with EMA/CO and identified an optimal hCG level to detect EMA/CO resistance in GTN. MATERIALS AND METHODS Eighty-one women with GTN treated with EMA...

OBJECTIVES The purpose of this study was to investigate whether therapy with nitroglycerin (GTN) would lead to abnormal coronary artery responses to the endothelium-dependent vasodilator acetylcholine. BACKGROUND Nitroglycerin therapy is associated with specific biochemical changes in the vasculature that may lead to increased vascular sensitivity to vasoconstrictors. METHODS Patients were ...

Mitochondrial aldehyde dehydrogenase (ALDH2) may be involved in the biotransformation of glyceryl trinitrate (GTN), and the inactivation of ALDH2 by GTN may contribute to the phenomenon of nitrate tolerance. We studied the GTN-induced inactivation of ALDH2 by UV/visible absorption spectroscopy. Dehydrogenation of acetaldehyde and hydrolysis of p-nitrophenylacetate (p-NPA) were both inhibited by...

Damage and dysfunction of the vascular endothelium critically influence clinical outcomes after ischemia and reperfusion (I/R). Brief exposure to organic nitrates can protect the vascular endothelium from I/R injury via a mechanism that is similar to ischemic preconditioning and is independent of hemodynamic changes. The clinical relevance of these protective effects clearly depends on whether ...

Nitrate tolerance developed after persistent nitroglycerin (GTN) exposure limits its clinical utility. Previously, we have shown that the vasodilatory action of GTN is dependent on endothelial nitric oxide synthase (eNOS/NOS3) activity. Caveolin-1 (Cav-1) is known to interact with NOS3 on the cytoplasmic side of cholesterol-enriched plasma membrane microdomains (caveolae) and to inhibit NOS3 ac...

OBJECTIVES This study was designed to assess the effect of oral L-arginine on the development of tolerance during continuous transdermal nitroglycerin (TD-GTN) therapy. BACKGROUND Continuous TD-GTN therapy leads to complete tolerance within 24 to 48 h. The mechanism(s) responsible for nitrate tolerance are unclear, but there is increasing evidence that nitroglycerin (GTN) leads to superoxide ...

Abstract We explore the acceleration effect on genuine tripartite nonlocality (GTN) for one or two accelerated detector(s) coupled to vacuum field with initial mixed states. show that Hawking radiation degrades physically accessible GTN, which suffers from “sudden death” at certain critical temperature. An novel phenomenon has been observed first time can generate inaccessible GTN fermion field...

Bioconversion of glyceryl trinitrate (GTN) into nitric oxide (NO) by aldehyde dehydrogenase-2 (ALDH-2) is a crucial mechanism which drives vasodilatory and antiplatelet effect of organic nitrates in vitro and in vivo. Oxidative stress generated by overproduction of free radical species, mostly superoxide anions and NO-derived peroxynitrite, has been suggested to play a pivotal role in the devel...

Nitroglycerin (glyceryl trinitrate, GTN) relaxes blood vessels primarily via activation of the soluble guanylyl cyclase (sGC)/cGMP/cGMP-dependent protein kinase (cGK-I) pathway. Although the precise mechanism of sGC activation by GTN in the vascular wall is unknown, the mediatory role of nitric oxide (NO) has been postulated. We tested the GTN/NO hypothesis in different types of isolated rat an...