Orexin (HCRT)

Neuropeptides that play a significant role in the regulation of food intake and sleep-wakefulness, possibly by coordinating the intricate behavioral and physiological responses of these complementary homeostatic functions. A wider role in the homeostatic regulation of energy metabolism, autonomic function, hormonal balance and the regulation of body fluids, is also proposed.

Orexin-A binds to both OX1R and OX2R with a high affinity, whereas orexin-B binds only to OX2R with a similar high affinity. .