This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
[{'content': 'The H3 receptor agonist exhibits all of the following actions except \nSelect and explain. \nA. Inhibition of H1 receptors induced wakefulness, B. Increase in H1 mediated gastric secretion, C. Inhibition of H1 mediated bronchoconstriction, D. Negative chronotropic effect on atria', 'role': 'user'}, {'content': 'Answer: B \nExplanation: H3 receptors act as presynaptic receptors and decrease the release of histamine and other neurotransmitters. this antagonize H1 mediated wakefulness and bronchoconstriction. these also decrease gastrin release and produced negative chronotropic effect inverse agonist and H3 receptor(tiprolisant) is proved for narcolepsy. Refer KDT 6/e p153', 'role': 'assistant'}]