Orexin-A

Orexin-A (Hypocretin-1)

Orexin-A, also known as Hypocretin-1, is a synthetic 33-amino acid neuropeptide identical in sequence to the endogenous orexin-A produced by a discrete population of neurons in the lateral hypothalamus. It is one of two orexin peptides (alongside Orexin-B/Hypocretin-2) that act as endogenous ligands for the orexin receptors OX1R and OX2R. Orexin-A has been extensively studied in preclinical research for its roles in arousal, wakefulness, energy homeostasis, reward processing, and autonomic regulation, and is a key research tool in the neuroscience of sleep-wake disorders and narcolepsy.

Mechanism of Action

Orexin-A binds with high affinity to both OX1R and OX2R — G-protein-coupled receptors (Gq/11 and Gi/o) expressed throughout the brain, including the locus coeruleus, dorsal raphe, tuberomammillary nucleus, and basal forebrain. OX1R and OX2R activation promotes the release of noradrenaline, serotonin, histamine, and acetylcholine from wake-promoting nuclei, stabilising the arousal state and suppressing transitions to sleep. Orexin-A also modulates dopaminergic reward circuitry in the ventral tegmental area and nucleus accumbens, and regulates food intake and energy expenditure through hypothalamic circuits.

Research Applications

• OX1R and OX2R pharmacology and orexin receptor signalling studies
• Arousal, wakefulness, and sleep-wake transition research
• Narcolepsy and orexin deficiency preclinical modelling
• Dopaminergic reward circuitry and addiction neuroscience investigation
• Energy homeostasis, appetite regulation, and autonomic function research

Specifications

• Molecular Formula: C₁₅₂H₂₄₃N₄₇O₄₄S₄
• Molecular Weight: 3561.1 g/mol
• CAS Number: 205640-90-0
• Purity: ≥98%
• Form: Lyophilised powder
• Storage: -20°C
• Shelf Life: 24 months

This product is intended for legitimate laboratory and analytical research use only. Not for diagnostic, therapeutic, or consumer use.