title: Modulation of lectin-stimulated lymphocyte agglutination and mitogenesis by estrogen metabolites: effects on early events of lymphocyte activation.
abstract: Pharmacological doses of estrogens such as 17-beta estradiol (17-beta E) and diethylstilbestrol (DES) suppress cell-mediated immunity in vivo. In this report, we investigated the direct in vitro effects of 17-beta E and its major metabolites on lymphocyte proliferation in response to the T cell lectin phytohemagglutinin (PHA). PHA-induced lymphocyte agglutination, an early event indicative of active, cytoskeletal-dependent membrane alterations, was monitored in conjunction with blastogenesis. Without exception, the effects of individual estrogen metabolites on the PHA-induced agglutination occurring within minutes were accompanied, at every concentration of compound, by equivalent effects on the blastogenic response of activated cells measured after several days. This observation suggested a role for estrogens in modulating lymphocyte activation at the cell surface rather than through cytosolic receptor-mediated events. As suggested by previous studies with quinone metabolites of benzene, the catechol estrogen metabolite 2-OH estrone (2-OH E) was significantly more potent than the parent compound at suppressing lymphocyte proliferation in vitro and in vivo.
mesh_terms: D000371:Agglutination / Q000187:drug effects*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D004229:Dithiothreitol / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006873:Hydroquinones / Q000494:pharmacology; D006894:Hydroxyestrones / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000187:drug effects*; D051379:Mice; D008938:Mitosis / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013053:Spectrophotometry
chemical_list: D004967:Estrogens; D006873:Hydroquinones; D006894:Hydroxyestrones; D010835:Phytohemagglutinins; D004958:Estradiol; D004229:Dithiothreitol; C031927:hydroquinone