title: [Kinetics of the testicular steroidogenic response to stimulation with placental gonadotropin in the prepuberal boy].
abstract: The kinetics of the plasma level responses of steroid hormones to a single injection of human chorionic gonadotrophin (hCG) (100 Ul/kg) was studied for one week in 7 prepubertal boys. Plasma testosterone levels progressively increased up to 8.22 +/- 1.33 nmol/l, usually at the 100th hour. The kinetics of dihydrotestosterone was quite similar. On the other and, progesterone, 17 alpha-hydroxyprogesterone and delta 4-androstenedione did not change significantly; 17 beta-estradiol slightly increased 5 to 7 days later. This profile of response is deeply different from those observed in adults, in whom are observed an early response (24 hrs) of 17 alpha-hydroxyprogesterone and estradiol and a two-phase response of testosterone. These results show that the hCG-induced steroidogenic desensitization is present only in patients previously exposed to a certain level of gonadotrophic stimulation (endogenous or exogenous).
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis / Q000097:blood; D006801:Humans; D007223:Infant; D007700:Kinetics; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D011627:Puberty; D013737:Testis / Q000201:enzymology; D013739:Testosterone / Q000096:biosynthesis / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D012739:Gonadal Steroid Hormones; D013739:Testosterone; D004958:Estradiol
vernacular_title: Cinétique de la réponse stéroïdogénique testiculaire à la stimulation par l'hormone gonadotrophique placentaire chez le garçon impubère.