This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'All use cAMP as second messenger during their physiological functions, EXCEPT: \nSelect and explain. \nA. Coicotropin receptors, B. D2-like Dopamine receptors, C. Glucagon receptors, D. V2 vasopressin receptors', 'role': 'user'}, {'content': "Answer: B \nExplanation: Activation of D1-type receptors leads to an increase in cAMP, whereas activation of D2-like receptors reduces cAMP levels. ACTH binds to high-affinity plasma membrane receptors, thereby activating adenylyl cyclase and increasing cyclic adenosine monophosphate, which in turn activates intracellular phosphoprotein kinases. In the liver, glucagon acts Gs to activate adenylyl cyclase and increase intracellular cAMP. This leads protein kinase A to activation of phosphorylase. The V2 receptors of vasopressin act through Gs to increase cyclic adenosine 3',5'-monophosphate (cAMP) levels. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 7. Neurotransmitters & Neuromodulators. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.", 'role': 'assistant'}]