Leptin, a palatability molecule? A Review

Leptin is a hormone involved in the regulation of feed intake and energy ba lance in animals. The expression and secretion of leptin is highly correlat ed with body fat mass and adipocyte size. The regulation of leptin is integ rated into a broad regulatory network including other hormones and cytokine s. Leptin's effects on food intake and energy expenditure is thought to be mediated centrally via various neurotransmitters. Peripheral hormones, incl uding insulin and glucocorticoids, stimulate the expression of leptin. Whil e leptin action has been well studied in rodents and humans, its role in fa rm animals remains to be determined in relation to feed intake and energy m etabolism. Leptin may play a role in the regulation of regional fat distrib ution. The deposition of intramuscular fat (marbling) is positively correla ted with the palatability of beef and, therefore, investigations into the m echanisms underlying fat accretion in this depot are underway. Studying the relationship between leptin and lipid metabolizing enzymes may provide us with clues on the mechanisms governing site-specific fat accretion in farm animals.