BETA-ENDORPHIN IN HUMAN-PLASMA - BASAL AND PATHOLOGICALLY ELEVATED LEVELS

β-Endorphin-like immunoreactivity was measured in plasma of normal human subjects and in plasma of patients with pathologically elevated ACTH levels. The antiserum used displayed the same avidity for human β-endorphin and human β-lipotropin (detection limit for both peptides 1-2 fmoles/tube). Gel chromatography of the immunoreactive components in plasma of normal subjects indicated the presence of both β-lipotropin (2.1 -10.1 fmoles/ml) and β-endorphin (3.5-6.4 fmoles/ml). A close correlation between immunoreactive β-endorphin and ACTH was found in plasma of patients suffering from Addison's disease, Cushing's disease and exhibiting Nelson's syndrome. Elevated levels of β-endorphin-like immunoreactivity in plasma of these patients were due to both β-lipotropin and β-endorphin. © 1979.