Leptin is secreted by-

Ans. is 'b' i.e., Adipose tissue Leptin* Leptin is a protein hormone produced by fat cells of adipose tissue. It acts on hypothalamus to reduce food intake, decrease lipogenesis and increase lipolysis, thereby reducing the body fat stores.* The effect of leptin on appetite is mediated through a-MSH (a-melanocyte stimulating hormone), a proopiomelanocortin (POMC) derivative. Leptin acts by increasing the synthesis of POMC which is converted into a-MSH. a-MSH acts through melanocortin-4 receptors to depress appetite.* Leptin also inhibits the secretion of Agouti-related peptide (AgRP), a neuropeptide that increases food intake.* Plasma leptin levels are proportional to the amount of body fat and are therefore higher in women and obese individuals.* Leptin level is increased ini) Obesityiv) Insulinii) Emotional stressv) Dexamethasoneiii) Estrogen * Leptin level is decreased by:i) Sleep deprivationiii) Exerciseii) Testosterone (androgen)iv) Starvation