Describe how acetylcholine mediates arterial smooth muscle r

Describe how acetylcholine mediates arterial smooth muscle relaxation and vasodialation.

Solution

Endothelium was considered as an inert, single layer of cells that served solely as a passive filter for water to pass across the blood vessel wall, blood cells and proteins to retain in the vascular compartment.However endothelium is now recognized as a source of substances that elicit contraction and relaxation of vascular smooth muscle. As you aware artery is also a smooth muscle. now great importance in endothelially mediated vascular dilation is the formation and release of endothelium derived relaxing factor (EDFR) which is identified as Nitric Oxide(NO).

Stimulation of endothelial cells with Acetylcholine results in the formation and release of an EDFR which is NO. The NO stimulates the guanylyl cyclase to increase cyclic guanosine monophosphate (cGMP) in the vascular smooth muscle to cause relaxation.
Stimulation of endothelial cells in vivo, in isolated arteries. or in culture by acetylcholine produce and release NO.In arteries whose endothelium has been removed acetylcholine do not elicit vasodilation.