All these hormones use cAMP as the second messenger except: (A) Coicotropin, (B) Dopamine, (C) Glucagon, (D) vasopressin
Answer is D. Vasopressin is a nonpeptide acting through GQPCR- a type of G protein-coupled cell membrane receptors which act through the phospholipase C-IP3/DAG pathway. (Ref.Essentials of medical pharmacology TD Tripathi 7th edition page no.593)