Appetite regulation via increased satiety

Appetite regulation via increased satiety is a multifaceted neurohormonal process centered in the hypothalamus, particularly the arcuate nucleus, where signals from gut hormones like ghrelin, cholecystokinin (CCK), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) integrate with adipose-derived leptin to balance hunger and fullness.[1][2][3] Ghrelin promotes hunger by activating growth hormone secretagogue receptor (GHSR-1a) and AgRP/NPY neurons, while satiety is enhanced by leptin binding to LepR receptors, stimulating pro-opiomelanocortin (POMC) neurons to release alpha-MSH, which acts on melanocortin receptors (MC3R/MC4R) to suppress appetite and boost energy expenditure.[1][3] Vagal afferents from the gut relay mechanical (distension) and chemical (hormone) cues to the nucleus tractus solitarius (NTS), further propagating satiety to hypothalamic regions like the paraventricular nucleus.[2] Dysregulation contributes to obesity through leptin resistance or imbalanced ghrelin-leptin ratios, disrupting energy homeostasis.[1][2] Therapeutically, GLP-1 receptor agonists mimic satiety signals to reduce food intake, though challenges include peripheral side effects and incomplete central penetration.[2][3]

Activation of satiety signals via hormones like leptin on LepR receptors in hypothalamus, stimulating POMC neurons and inhibiting AgRP/NPY neurons; Gut hormone effects (e.g., GLP-1, PYY, CCK) relaying fullness to brainstem and hypothalamus via vagal afferents