You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is NO is released by - and explain in detail?
Ans. is 'c' i.e., Endothelial cells o The most important physiological source of NO is endothelial cells.o Nitric oxide, also called endothelium-derived-relaxing factor (EDRF), is formed from amino acid arginine, by the action of the enzyme NO synthase, which is cytosolic.o NO acts as short lived biological messenger by stimulating a guanyl cyclase that produce cGMP and cGMP activates protein kinase G.o The most important actions is the relaxation of smooth muscles. The constant release of NO from endothelial cells produces vasodilatation, and basal release of NO produced by endothelial cells is a primary determinant of resting vascular tone. In GIT, NO produces relaxation of GI smooth muscles. Vasodilatation in corpora covernosa helps in penile erection.o NO inhibits platelets adhesion, activation and aggregationo Cigarette smoking decreases endogenous NO formation