Immunoreactive orexin-A in human plasma.
Orexin-A and orexin-B are newly discovered neuropeptides which are implicated in feeding behavior and arousal state. We studied immunoreactive(IR)-orexin-A concentrations in human plasma by radioimmunoassay. IR-orexin-A concentrations in plasma obtained from 17 healthy subjects in the morning were 1.94 +/- 0.24 pmol/liter (mean +/- SEM). IR-orexin-A levels in the plasma obtained at night were not significantly different from those obtained in the morning in 9 female subjects. The HPLC analysis of the plasma extract showed two immunoreactive peaks; one peak eluting in an identical position to synthetic orexin-A, and one eluting earlier. This study has shown for the first time the presence of orexin-A in human plasma.
Arihara
Z
Z
Second Department of Internal Medicine, Tohoku University School of Medicine, Sendai, 980-8574, Miyagi, Japan.
Takahashi
K
K
Murakami
O
O
Totsune
K
K
Sone
M
M
Satoh
F
F
Ito
S
S
Mouri
T
T
D000328:Adult; D002352:Carrier Proteins / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000097:blood*; D000068797:Orexins; D011863:Radioimmunoassay
D002352:Carrier Proteins; C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins