Pharmacology and toxicology of nitroglycerin aerosol

The main pharmacological action of all nitrates is the same, which is to relax vascular smooth muscle. Organic nitrate releases nitric oxide (NO) in the body. NO, like endothelial relaxing factor, activates guanosine cyclase and increases cyclic guanosine monophosphate (cGMP) in smooth muscle cells, thus relaxing vascular smooth muscle and dilating peripheral arteries and veins, which has a stronger dilating effect on veins. Vein dilation makes blood stay in the periphery, the amount of returned blood decreases, and the left ventricular end diastolic pressure and pulmonary capillary wedge pressure (preload) decrease. Arterial dilation reduces peripheral vascular resistance, systolic arterial pressure and mean arterial pressure (afterload). Coronary artery dilation increases coronary artery perfusion. The overall effect is to reduce myocardial oxygen consumption, increase oxygen supply and relieve angina pectoris. No carcinogenicity and mutagenicity were observed in animal experiments.