This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
[{'content': 'Ghrelin is responsible for \nSelect and explain. \nA. Stimulation of appetite, B. Suppression of appetite, C. Stimulation of sleep, D. Suppression of sleep', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ghrelin: A naturally occurring 28-amino acid; gut-brain growth hormone releasing peptide (GHRP) that is expressed mainly in the stomach and possibly in the hypothalamus. Fasting and hypoglycemia increase ghrelin levels and circulating ghrelin levels are decreased in chronic obesity, following acute caloric intake and in states of positive energy balance. Acute administration of ghrelin to humans induces a feeling of hunger. Ghrelin binds to ghrelin-receptors in the anterior pituitary and possibly in the mediobasal and mediolateral hypothalamus to stimulate growth hormone release and to regulate energy homeostasis. Serum levels of ghrelin are measurably higher in patients who have lost weight through dietary measures.Ref: Ganong&;s review of medical physiology 23rd edition Page no: 384', 'role': 'assistant'}]