Nitrates mechanism of action

Vasodilators are a group of dtugs, which relax the smooth muscle cells of the blood vessels and lead to an increased local tissue blood flow, a reduced arterial pressure and a reduced central venous pressure. Vasodilators reduce the cardiac pre-load as well as after-load and thereby reduce cardiac work. They are used in a variety of conditions including hypertension, cardiac failure and treatment/prevention of angina pectoris. Major groups are Ca2+-channel blockers (e.g. dihydropyridines), NO-donators (e.g. organic nitrates), K+-channel openers (minoxidil), phosphodiesterase inhibitors (e.g. sildenafil), Rho-kinase inhibitors (e.g. Y27632) or substances with unknown mechanism of action (e.g. hydralazine). Inhibitors of the... 

Silver and mercury salts have a long history of use as antibacterial agents.241-243 The use of mercurochrome ((40), Figure 18) as a topical disinfectant is now discouraged. Silver sulfadiazene (38) finds use for treatment of severe burns the polymeric material slowly releases the antibacterial Ag+ ion. Silver nitrate is still used in many countries to prevent ophthalmic disease in newborn children.244 The mechanism of action of Ag and Hg is through slow release of the active metal ion—inhibition of thiol function in bacterial cell walls gives a rationale for the specificity of bacteriocidal action. 

As mentioned earlier, the therapeutic use of organic nitrites [4] actually predates that of organic nitrates [1], Clinical utilisation of nitrites has, however, been very much less and this is reflected in the relatively sparse attention given to their mechanisms of action. Alkyl nitrites react readily with thiols to form S-nitrosothiols [122], which show biological effects similar to those of NO [11]. Nevertheless, glutathione-S-transferase has been implicated in the metabolism of organic nitrites, via intermediate... 

Organic nitrate esters clinical use and mechanisms of actions. Pharmacd. Rev. 43 (1991), p. 351-423... 

Abortion in pregnant cattle is frequently reported but exact amounts and mechanism of action is not fully understood. The fetus is particularly susceptible to hypoxia induced by the methemoglobinemia. Fetal death and abortion may occur at any stage of pregnancy because of the decreased fetal oxygen and the limited ability of the fetus to metabolize nitrate (Knight and Walter, 2001). 

It seems likely that the mechanism of action of all of the organic nitrates and nitrites should be analogous. They exhibit direct relaxant effects on vascular, smooth musculature, which results in general dilation of vessels—predominantly veins, bnt also arteries to a... 

The mechanism of action of nitroglycerin and other organic nitrates is thought to involve an interaction with nitrate receptors that are present in vascular smooth muscle. Intact vascular endothelium is not necessary for... 

Torfgard KE and Ahlner J. Mechanisms of action of nitrates. Cardiovasc Drug Ther 1994 8 701-717. 

Mechanism of Action A nitrate that stimulates intracellular cyclic guanosine monophosphate. Therapeutic Effect Relaxes vascular smooth muscle of both arterial and venous vasculature. Decreases preload and afterload. 

Mechanism of Action A nitrate that decreases myocardial oxygen demand. Reduces left ventricularpreload and afterload.Tiierapeutic Effect Dilates coronary arteries and improves collateral blood flow to ischemic areas within myocardium. IV form produces peripheral vasodilation. 

It can be given sublingually and orally for treatment of angina. Mechanism of action is same as nitrates. 

Mechanism of action of nitrates, nitrites, and other substances that increase the concentration of nitric oxide (NO) in vascular smooth muscle cells. Steps leading to relaxation are shown with heavy arrows. MLCK, activated myosin light-chain kinase [see Figure 12-1]. GC, activated guanylyl cyclase PDE, phosphodiesterase eNOS, endothelial nitric oxide synthase. 

All therapeutically active agents in the nitrate group have identical mechanisms of action and similar toxicities. Therefore, pharmacokinetic factors govern the choice of agent and mode of therapy when using the nitrates. 

Given the notion of microscopic reversibility, and the similarity in the active sites of sulfite oxidase and nitrate reductase (assimilatory), determining the mechanism of action of sulfite oxidase impacts upon our understanding of reductases in the (MPT)Mo(0)2 family. A key issue in the mechanism of sulfite oxidase is whether substrate binds to the metal center during the catalytic cycle. Substrate (or product) binding to the molybdenum center, as proposed for the catalytic... 

Hydralazine causes direct relaxation of arteriolar smooth muscle. The arteriolar vasodilatation produced by hydralazine requires an intact endothelium. Therefore, one proposed mechanism of action is that hydralazine liberates nitric oxide from the endothelium (similar to the nitrates), which in turn increases cGMP to ultimately prevent the phosphorylation of myosin light chain (which is required for smooth muscle contraction) resulting in arteriolar vasorelaxation. 

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