cAMP is the exclusive second messenger for all the following except

cAMP is the second messenger for dopamine, coicotrophin and glucagon. Vasopressin (ADH) acts on atleast 3 kinds of receptors: V-1A, V-1B, V2. All the 3 are G-protein coupled receptors. V-1A and V-1B receptors (Gq) act through IP3 as a second messenger, to increase the intracellular calcium concentration. V2 receptors (Gs) use cAMP as a second messenger. Dopamine has 5 receptors (D1, D2, D3, D4, D5) All use cAMP as second messengers. D1, D5 act by increasing cAMP. D2, D3, D4 act by decreasing cAMP. Coicotrophin (ACTH) and glucagon use cAMP as a second messenger. Ref: Ganong's Medical physiology 26th edition PGno: 685