Radioimmunoassay for beta-endorphin (1-18), a novel pituitary peptide derived from proopiomelanocortin.
A specific radioimmunoassay was developed for beta-endorphin (1-18). The content of beta-endorphin (1-18) immunoreactivity in rat tissues was as follows: posterior pituitary 260 ng/fragment, anterior pituitary 1.46 ng/mg, hypothalamus 11.9 pg/mg. The levels were undetectable (less than 3 pg/mg) in extrahypothalamic brain, pancreas, small intestine, prostata and testis. Gel filtration and reverse-phase HPLC studies indicated that most of rat anterior pituitary immunoreactivity is due to native beta-endorphin (1-18), whereas the bulk of posterior pituitary immunoreactivity corresponds to more hydrophobic material, probably N-acetyl-beta-endorphin (1-18). Thus, beta-endorphin (1-18) is a quantitatively important novel pituitary peptide derived from proopiomelanocortin. The posterior pituitary is an especially rich source of (N-acetyl)-beta-endorphin (1-18).
D000818:Animals; D001923:Brain Chemistry; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000032:analysis*; D008297:Male; D010446:Peptide Fragments / Q000032:analysis*; D010902:Pituitary Gland / Q000032:analysis*; D011333:Pro-Opiomelanocortin / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D001615:beta-Endorphin
D004723:Endorphins; D010446:Peptide Fragments; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin; C042186:beta-endorphin (1-18)