title: Sex hormone binding globulin and transcortin in human and baboon males.
abstract: TeBG and transcortin were identified in serum from adult male baboons. TeBG values were higher than the TeBG concentration in adult men. The relative competitive abilities of three natural steroids, a synthetic androgen and two synthetic estrogens, for binding sites on TeBG occupied by radioactive DHT were compared. At a 10-fold molar excess, using both baboon and human TeBG, DHT and T were the most effective competitors; E2 was intermediate and DES a very poor one. Using gel filtration, the transcortin concentrations (mg/L) in two baboons were 16.8 and 27.4; the normal range for men is 23--45. The serum transcortin value of a third baboon, determined by equilibrium dialysis, was 0.41 micron/L (21.5 mg/L). Competition studies, using both techniques, showed that progesterone has a slightly higher affinity for baboon transcortin than cortisol and that a synthetic progestin does not bind to transcortin. Plasma binding capacity for synthetic steroids should be tested before they are used for studies on specific tissue receptors contaminated with serum.
mesh_terms: D000818:Animals; D004054:Diethylstilbestrol / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D045166:Estradiol Congeners / Q000378:metabolism; D000882:Haplorhini; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008297:Male; D010215:Papio / Q000097:blood*; D011374:Progesterone / Q000378:metabolism; D012738:Sex Hormone-Binding Globulin / Q000032:analysis* / Q000378:metabolism; D045165:Testosterone Congeners / Q000378:metabolism; D014156:Transcortin / Q000032:analysis*
chemical_list: D045166:Estradiol Congeners; D012738:Sex Hormone-Binding Globulin; D045165:Testosterone Congeners; D013196:Dihydrotestosterone; D011374:Progesterone; D004958:Estradiol; D004054:Diethylstilbestrol; D014156:Transcortin; D006854:Hydrocortisone