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: Biochemistry
[{'content': 'Primary component of nonadrenergic noncholinergic nerve transmission in gut is: \nSelect and explain. \nA. VIP and NO, B. VIP and CCK, C. VIP and Motilin, D. VIP and substance', 'role': 'user'}, {'content': "Answer: A \nExplanation: Vasoactive intestinal peptide (VIP) It is usually produced by neurons It is a potent vasodilator, cause smooth muscle relaxation, increases blood flow and epithelial cell secretion It is the primary component of nonadrenergic noncholinergic neurotransmission in gut along with nitric oxide (NO). Lack of VIP innervations plays a role in achalasia and Hirschsprung disease. Ref: Sleisenger and Fordtran's, Edition-9, Page-7.", 'role': 'assistant'}]