beta-Lipotropin is the major opioid-like peptide of human pituitary and rat pars distalis: lack of significant beta-endorphin.

摘要: Abstract beta-Lipotropin is the predominant opioid peptide of human pituitary and rat pars distalis present in concentrations essentially equimolar with corticotropin. When freshly, obtained nonfrozen anterior pituitaries were homogenized 0.2 M HCl, approximately 98% immunoreactivity detected utilizing an antiserum that crossreacts equally beta-lipotropin beta-endorphin coeluted 125I-labeled upon molecular sieve chromatography. The remainder activity eluted synthetic beta-endorphin. Similar results for pituitary. HCl homogenization thawed tissue or fresh acetic acid yielded substantially greater decreased beta-lipotropin. In subjects, acute stimulation using either insulin-induced hypoglycemia vasopressin administration was associated increased plasma corticotropin levels. At time peak concentrations, no significant levels detectable. These data indicate lack amounts Additionally, there appears to be specific intrapituitary conversion