title: Heterogeneity of human luteinizing hormone in pituitary tumor homogenates and cell incubates.
abstract: Incubation media of pituitary cells and homogenates of pituitary tumors were studied by isoelectric focusing followed by radioimmunoassay. Almost all LH-immunoreactive components detected had been observed in earlier studies on highly purified preparations. In one pituitary tumor homogenate, intact LH (LHi) was detected. The majority of LHi-components present in this tumor were relatively acidic (LH Type I) components. The corresponding beta-subunit population was in agreement with the one earlier observed for Type I LH. In all other tumor homogenates only alpha- and beta-subunits could be detected. In incubation media of pituitary cells from patients with no known endocrine disease nor a pituitary tumor highly acidic populations of alpha-subunits were detected. In only one of the incubation media significant amounts of LHi and free beta-subunits were observed. In an incubation medium of a TSH-producing pituitary tumor significant amounts of intact LH, free alpha- and beta-subunits were detected. The cell contents of this tumor contained components with lower pl-values than the medium. In general a good correlation is observed between the population of LH-components in material from individual identifiable pituitary glands and in highly purified preparations from large numbers of anonymous pituitary glands.
authors.affiliation: National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
authors.forename: L A
authors.initials: LA
authors.lastname: van Ginkel
authors.forename: H H
authors.initials: HH
authors.lastname: Somers
authors.forename: J G
authors.initials: JG
authors.lastname: Loeber
mesh_terms: D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D005260:Female; D006801:Humans; D007525:Isoelectric Focusing; D007986:Luteinizing Hormone / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D009924:Organ Culture Techniques; D010902:Pituitary Gland / Q000737:chemistry*; D010911:Pituitary Neoplasms / Q000737:chemistry* / Q000378:metabolism; D011863:Radioimmunoassay; D013972:Thyrotropin / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
chemical_list: D017077:Culture Media, Conditioned; D007986:Luteinizing Hormone; D013972:Thyrotropin