Write a 4 page essay on Discuss the mechanisms by which substances act directly on vascular smooth muscle to cause vasodilatation. In addition identify potential targets in vascular myocytes for devel

Write a 4 page essay on Discuss the mechanisms by which substances act directly on vascular smooth muscle to cause vasodilatation. In addition identify potential targets in vascular myocytes for development of new drugs in the treatment of cardiovascular disease.

The EDRF enables the relaxation of blood vessels eventually affiliated with the substance nitric oxide (NO) although there are other factors that can bring about vasodilatation like prostacyclin and endothelium-derived hyperpolarizing factor (Woods, Froelicher & Motze 2004. Bronzino 2000).

EDRF is released by the vascular endothelium either spontaneously (basal release) or as a result of the stimulation of the endothelium by intracellular and extracellular factors.

Release of EDRF by stimulation of the vascular endothelium may be induced by the following: blood flow. agonists. calcium. magnesium. calcium and inositol phosphates. mitochondrial ATP. cyclic GMP, and. protein kinase C (Ryan & Rubandi 1991 139). Many of the vasodilators in the market follow one principle or the other of endothelium stimulation to dilate the blood vessels and provide relief to elevated blood pressure.

Directly acting vasodilators are so called because they do not stimulate or act upon the nervous system to induce vasodilatation but directly act on the vascular smooth muscles. The advantage of direct acting vasodilators is that they diminish peripheral resistance and as a result normalize aberration in blood circulation which caused the elevation of the blood pressure. They also lower blood pressure whatever may be its causes because of their direct acting capability on the vascular smooth muscle. Unlike other antihypertensive agents, directly acting vasodilators do not result in side effects like hypotension and impotence. Their disadvantage however is that they cannot be used indefinitely and chronically because of the natural neuroendocrinic and autonomic reflexes of the human body that can compromise the fall in blood pressure (Craig & Stitzel 2003).

. There is however no single or unified mechanism of action of vasodilators because different vasodilators act at different places and phases in the vascular smooth