Shoest half life is of ?
Ans. is'b'i.e., Acetylcholine Acetylcholine is very rapidly hydrolyzed; large amounts must be infused intravenously to achieve concentrations sufficient to produce detectable effects.Methacholine is more resistant to hydrolysis, and the carbamic acid esters carbachol and bethanechol are still more resistant to hydrolysis by cholinesterase and have correspondingly longer duration of action.
Metacholine
Acetyl choline
Carbachol
Bethanechol