The main pharmacological action is to relax vascular smooth muscle. Nitroglycerin releases nitric oxide (NO), which is the same as endothelial relaxing factor, activating guanylate cyclase, increasing cyclic guanosine monophosphate (cGMP) in smooth muscle and other tissues, leading to dephosphorylation of myosin light chain, regulating the contractile state of smooth muscle, and causing vasodilation.

It inhibits the reuptake of 5-hydroxytryptamine and norepinephrine by the central nervous system, thereby increasing the concentration of these two neurotransmitters in the synaptic cleft and exerting an antidepressant effect. It also has antianxiety and sedative effects.

By blocking the membrane transport of calcium ions in myocardial and vascular smooth muscle, inhibiting the influx of calcium ions into cells, it causes a decrease in myocardial contractility and vasodilation. Animal experiments have shown that by reducing myocardial contractility and peripheral vascular resistance, myocardial oxygen consumption is reduced; by dilating coronary vessels and developing collateral circulation, the oxygen supply to myocardial ischemic sites is increased; by inhibiting the consumption of high-energy phosphate compounds, the ability to resist hypoxia is enhanced.

Progestogens act on the endometrium and promote the proliferation and secretion of the endometrium. Through negative feedback to the hypothalamus, they inhibit the release of luteinizing hormone from the anterior pituitary and inhibit the ovulation process of the ovary. The anti-cancer effect may be related to the anti-estrogen effect.

Extract from the above information