title: Radioimmunoassay for orexin A.
abstract: A radioimmunoassay for orexin A has been developed. Anti-orexin A antiserum was raised in New Zealand white rabbits immunized with a conjugate of synthetic orexin A with bovine serum albumin. This antibody did not crossreact with orexin B, hypothalamic hormones, pituitary hormones, neuropeptides or gut hormones. Radioiodination of orexin A was performed with the chloramin T method, followed by purification of radioiodinated material on Sephadex G-25 column. Orexin A was extracted from tissues using acid-acetone. The assay was performed with a double antibody system. The dilution curve of acid-acetone-extracts of rat hypothalamus in the radioimmunoassay system was parallel to the standard curve. The recovery of tissue orexin A was about 80%,and the intra-assay and inter-assay variations were 5.2% and 7.8%, respectively. Orexin A was found in the hypothalamus, cerebrum and testis. These data suggest that this assay system is suitable for the measurement of tissue orexin A and that orexin A is found in the central nervous system and testis.
authors.affiliation: Fourth Department of Internal Medicine, Aichi Medical University, Aichi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mitsuma
authors.forename: Y
authors.initials: Y
authors.lastname: Hirooka
authors.forename: M
authors.initials: M
authors.lastname: Kayama
authors.forename: Y
authors.initials: Y
authors.lastname: Mori
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoi
authors.forename: N
authors.initials: N
authors.lastname: Rhue
authors.forename: J
authors.initials: J
authors.lastname: Ping
authors.forename: M
authors.initials: M
authors.lastname: Izumi
authors.forename: R
authors.initials: R
authors.lastname: Ikai
authors.forename: K
authors.initials: K
authors.lastname: Adachi
authors.forename: T
authors.initials: T
authors.lastname: Nogimori
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002352:Carrier Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange; D007106:Immune Sera; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009479:Neuropeptides / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D000068797:Orexins; D011817:Rabbits; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results
chemical_list: D002352:Carrier Proteins; D007106:Immune Sera; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins