Endocrine Abstracts

Orexins mediate a variety of physiological processes including feeding behaviour, the circadian pathway and cortisol secretion. Steroidogenesis is regulated by a variety of neuropeptides and one of the key rate-limiting steps is cholesterol transport across the mitochondrial membrane by the steroidogenic acute regulatory (StAR) protein. StAR expression can be regulated through several different signalling pathways. Despite the clear link between orexins and steroid production,...

Orexin-A and orexin-B orchestrate their diverse central and peripheral effects via two G-protein coupled receptors, OX1R and OX2R, which activate multiple G-proteins. They are involved in a host of physiological processes including, steroidogenesis, appetite control and energy regulation. Whilst some signalling mechanisms have been proposed for individual recombinant orexin receptors in generic mammalian cell types, it is clear that the peripheral effects of orexin are spatial...