title: Digoxin-like immunoreactivity in cord blood plasma extracts is not only due to endogenous corticosteroids.
abstract: Methods for quantitative extraction and enrichment of digoxin-like immunoreactive substances (DLIS) from human cord blood plasma (CBP) using organic solvents combined with a solid state absorbent are presented. Sephadex LH-20 column chromatography is more suitable than sephadex G-25 for DLIS separation and purification from CBP extract. The elution pattern of sephadex LH-20 chromatography of deproteinized and desalted CBP shows two distinct DLIS peaks. The first peak coelutes with the steroids aldosterone, cortisol, progesterone, 17-OH-progesterone, testosterone and estradiol, while the second DLIS peak coelutes with dehydroepiandrosterone sulfate (DHEA-S). The Na+,K(+)-ATPase inhibitory activity peak partially overlaps with the first DLIS peak. Coeluted steroids could account only partially for digoxin-like immunoreactivity in the first DLIS peak; however, they did not contribute to the Na+,K(+)-ATPase inhibitory activity, whereas the second DLIS peak could be ascribed to endogenous DHEA-S.
authors.affiliation: Department of Internal Medicine, Alexandra General Hospital, Athens, Greece.
authors.forename: L
authors.initials: L
authors.lastname: Yiannakou
authors.forename: E
authors.initials: E
authors.lastname: Loucari-Yiannakou
authors.forename: A
authors.initials: A
authors.lastname: Souvatzoglou
mesh_terms: D000305:Adrenal Cortex Hormones / Q000276:immunology; D001798:Blood Proteins / Q000276:immunology / Q000302:isolation & purification*; D002298:Cardenolides; D002850:Chromatography, Gel; D003429:Cross Reactions; D004077:Digoxin; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D012503:Saponins
chemical_list: D000305:Adrenal Cortex Hormones; D001798:Blood Proteins; D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin