Description

Orexin B is a hypothalamic neuropeptide that regulates feeding behavior, wakefulness, and behavior under situations of high motivational relevance. It is an agonist of orexin (OX) receptors with IC₅₀ values of 420 and 36 nM for human recombinant OX₁ and OX₂ receptors, respectively, expressed in CHO cells. It induces transient increases in intracellular calcium in CHO cells stably expressing OX₁ and OX₂ (EC₅₀s = 2,500 and 60 nM, respectively) and in primary rat ventral tegmental area (VTA) dopaminergic neurons. Orexin B stimulates arachidonic acid release from CHO cells expressing human recombinant OX₁ (EC₅₀ = 4.17 nM). It also stimulates food intake in freely feeding mice and goldfish when administered at intracerebroventricular doses of 30 nmol and 10 ng/g, respectively.

Uses

Orexin B, human is an endogenous agonist at Orexin receptor with Kis of 420 and 36 nM for OX1 and OX2, respectively.

Biochem/physiol Actions

Orexins/Hypocretins, Orexin A/ hypocretin-1 and Orexin B/ hypocretin-2, are excitatory neuropeptides that mediate there effects via two receptors, OX-1 and OX-2. Orexins are involved in food intake, obesity regulation, energy homeostasis and differentiation.

in vivo

storage

-20°C (desiccate)

References

[1] Smart D, et al. Orexins: a new family of neuropeptides. Br J Anaesth. 1999 Nov;83(5):695-7. DOI:10.1093/bja/83.5.695
[2] Sakurai T, et al. Orexins and orexin receptors: a family of hypothalamic neuropeptides and G protein-coupled receptors that regulate feeding behavior. Cell. 1998 Feb 20;92(4):573-85. DOI:10.1016/s0092-8674(00)80949-6