Avian beta-endorphin: alterations in immunoreactive forms in plasma and pituitary of embryonic and adult chickens.
1. A heterologous radioimmunoassay for beta-endorphin (beta-endo) was established. Plasma and/or extracts of pituitaries from embryonic (days 14.5 and 17.5 of incubation), newly hatched, and adult chickens were chromatographed on a Sephadex G-75 column with 0.1 M acetic acid. 2. Embryonic plasma had only a single immunoreactive peak that eluted similar to a beta-lipotropin (beta-LPH) standard. In contrast, adult plasma had 2 peaks, co-eluting with beta-LPH (34%) and beta-endo (66%). 3. Chromatography of pituitary extracts demonstrated two immunoreactive peaks in both embryonic and adult birds. Although 70% of immunoreactivity eluted with beta-endo for embryonic birds, 80% eluted with beta-LPH from adults. 4. The smaller proportion of beta-endo in adult pituitaries may reflect a higher rate of secretion of this hormone into the blood.
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles 90033.
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Hylka
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Thommes
D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000097:blood / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011863:Radioimmunoassay; D001615:beta-Endorphin / Q000097:blood / Q000378:metabolism*
D001615:beta-Endorphin