Radioimmunoassay for orexin A.
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.
Mitsuma
T
T
Fourth Department of Internal Medicine, Aichi Medical University, Aichi, Japan.
Hirooka
Y
Y
Kayama
M
M
Mori
Y
Y
Yokoi
Y
Y
Rhue
N
N
Ping
J
J
Izumi
M
M
Ikai
R
R
Adachi
K
K
Nogimori
T
T
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
D002352:Carrier Proteins; D007106:Immune Sera; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins