Vascular physiological action

After highlighting the present top ten pharmaceuticals, let us now cover a number of other important drugs, both prescription and over-the-counter. We will attempt to categorize them by physiological action but will emphasize chemical structure and synthesis where appropriate. Our first type will be drugs affecting the heart. Cardiovascular agents are used for their action on the heart or on other parts of the vascular system. They modify the total output of the heart or the distribution of blood to certain parts of the circulatory system. 

Physiological sites proposed for nitric oxide action include the immune system, where nitric oxide acts as a cytostatic agent, is tumoricidal, and can inhibit viral replication. In the cardiovascular system, nitric oxide is the biological mediator of vasodilator responses to agents such as acetylcholine and bradykinin, which act as receptors on endothelial cells to activate NOS and stimulate nitric oxide production. Diffusible nitric oxide then activates guanylate cyclase in vascular smooth muscle cells, leading to the production of cyclic guano-sine monophosphate (GMP) and vasodilation. In the brain, stimulation of A-methyl-o-aspartate receptors on... 

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