does response of acetylcholine smooth muscle contraction
Contraction of smooth muscle by acetylcholine is mediated by activation of muscarinic receptors of which M2 and M3 subtypes are present in longitudinal muscle of guinea pig intestine.he rise in internal calcium suppresses the voltage-dependent inward calcium current. A third important effect is the opening of channels which cause depolarization of the membrane and so increase action potential discharge and contraction in the whole muscle.