Psychiatry related information on HCRT

• Orexin-A has recently been identified as a new hypothalamic peptide working as a mediator in the regulation of feeding behavior and sleep control [1].

High impact information on HCRT

• These peptides, termed orexin-A and -B, have no significant structural similarities to known families of regulatory peptides. prepro-orexin mRNA and immunoreactive orexin-A are localized in neurons within and around the lateral and posterior hypothalamus in the adult rat brain [2].
• These findings suggest that orexin-A activates tyrosine hydroxylase and then stimulates catecholamine synthesis, probably via activation of the OX(1)R-protein kinase C pathway in adrenal medullary cells [1].
• To determine the role of orexin-A in peripheral metabolic processes, we examined direct effects of orexin-A on catecholamine synthesis and secretion in cultured bovine adrenal medullary cells [1].
• 4 beta-Phorbol-12 beta-myristate-13 alpha-acetate, an activator of protein kinase C, did not enhance the stimulatory effects of orexin-A on tyrosine hydroxylase activity, while H-7 and staurosporine, inhibitors of protein kinase C, nullified the effects of orexin-A [1].
• Orexin-A (100 pM) potentiated the stimulatory effects of acetylcholine (0.3 mM) on 14C-catecholamine synthesis [1].

Biological context of HCRT

• 2. Our aim was to elucidate whether central injection of mammalian orexin-A or -B stimulates food intake in the chick [3].
• Intracerebroventricular administered orexin-A stimulates food intake and energy expenditure [4].

Anatomical context of HCRT

• Orexin-A is a neuropeptide consisting of 33 amino acids with two intrachain disulfide bonds, namely Cys6-Cys12 and Cys7-Cys14, and is a potent stimulator of food consumption and gastric acid secretion [5].
• Orexin A was found in the hypothalamus, cerebrum and testis [6].

Associations of HCRT with chemical compounds

• The ability of the stimulation of gastric acid output was less in three alanine-substituted orexin-A, [Ala(6,12)]orexin-A, [Ala(7,14)]orexin-A, and [Ala(6,7,12,14)]orexin-A, than orexin-A [5].
• Radioiodination of orexin A was performed with the chloramin T method, followed by purification of radioiodinated material on Sephadex G-25 column [6].

Other interactions of HCRT

• Orexin-A significantly increased tyrosine hydroxylase activity, which was evident at 1 pM and maximal at 100 pM [1].

Analytical, diagnostic and therapeutic context of HCRT

• Radioimmunoassay for orexin A [6].

References