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': 'Which is NOT a function of gastrin? \nSelect and explain. \nA. Stimulation of gastric acid, B. Stimulation of pepsin, C. Stimulation of growth of the gastric mucosa, D. Stimulation of direct cholesterol absorption', 'role': 'user'}, {'content': "Answer: D \nExplanation: Stimulation of cholesterol absorption is not a function of gastrin. Gastrin has been shown to have effects on gut motility (increase). Pepsin release by gastrin is for breakdown of food into smaller paicles for fuher digestion. Growth of the gastric mucosa is also dependent upon gastrin. Gastrin also causes concentration of the musculature that closes the gastroesophageal junction. It stimulates insulin and glucagon secretion, but only after a protein meal and not a carbohydrate meal. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 25. Overview of Gastrointestinal Function & Regulation. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.", 'role': 'assistant'}]