Megestrol acetate exerts its appetite-stimulating effect partly by inducing release of which hypothalamic neuropeptide?

• A. Ghrelin
• B. Leptin
• C. Cholecystokinin
• D. Neuropeptide Y

Answer: (D)

Appetite regulation relies on signaling peptides in the hypothalamus, with neuropeptide Y being a principal driver of hunger. Neuropeptide Y, produced by neurons in the arcuate nucleus, strongly stimulates feeding when released and acts on hypothalamic receptors to promote caloric intake. Megestrol acetate increases appetite in part by triggering the release of neuropeptide Y, enhancing hunger signals and food consumption. Other options play different roles: leptin tends to suppress appetite by inhibiting NPY; cholecystokinin promotes fullness from the gut; ghrelin from the stomach can boost hunger by influencing hypothalamic pathways, but the direct hypothalamic peptide involved here is neuropeptide Y.