Age-related changes in endogenous steroids of human fetal testis during early and midpregnancy.

The steroidogenic activity of human fetal testes during early and midgestation was monitored by analyzing 58 individual fetal testes (aged 6-20 weeks of pregnancy) for endogenous pregnenolone (P5), progesterone, 17-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone (T) and estradiol. A clear increase in testicular steroid concentrations, especially in those of T and other 3-keto-4-ene steroids, occurred between 8-11 weeks of gestation and reached maximum between 11-14 weeks. The three steroids present in highest concentrations were P5, androstenedione, and T (maximum concentrations, 1.9-2.7 ng/mg wet tissue). The levels of all of the C-19 steroids measured decreased clearly between weeks 14-20 of gestation, whereas those of the C-21 steroids, P5, progesterone, and 17-hydroxyprogesterone, remained relatively high. Our results suggest that the metabolic reactions converting P5 to androgens are activated in the human fetal testis within a short time range between 8-11 weeks of gestation. The increased androgen production is possibly a consequence of increased 3 beta-hydroxysteroid dehydrogenase activity. Testicular androgen production decreases in the beginning of the second trimester of pregnancy, most likely due to a blockade in the C-21 steroid side-chain cleavage.

[1]  G. Erickson,et al.  Direct inhibitory effect of enclomiphene citrate and estradiol on testis functions in hypophysectomized rats. , 1980, Biology of reproduction.

[2]  K. Catt,et al.  Estrogen dependence of a gonadotropin-induced steroidogenic lesion in rat testicular Leydig cells. , 1980, The Journal of clinical investigation.

[3]  M. H. Melner,et al.  The direct effect of 17 beta-estradiol on LH-stimulated testosterone production in hypophysectomized rats. , 1980, Journal of steroid biochemistry.

[4]  W. H. Moger.  Temporal changes in testicular estradiol and testosterone concentrations, cytoplasmic estradiol binding, and desensitization after human chorionic gonadotropin administration to the immature rat. , 1980, Endocrinology.

[5]  J. Raeside,et al.  Development of testosterone secretion in the fetal pig testis. , 1979, Biology of reproduction.

[6]  K. Kouvalainen,et al.  Serum steroids and pituitary hormones in infants with particular reference to testicular activity. , 1979, The Journal of clinical endocrinology and metabolism.

[7]  P. Kellokumpu-Lehtinen,et al.  Early cytodifferentiation of human prostatic urethra and Leydig cells , 1979, The Anatomical record.

[8]  K. Catt,et al.  Direct inhibitory effect of estrogen on Leydig cell function of hypophysectomized rats. , 1978, Endocrinology.

[9]  K. Catt,et al.  Regulation of luteinizing hormone receptors and steroidogenesis in gonadotropin-desensitized leydig cells. , 1978, The Journal of biological chemistry.

[10]  G. Hammond,et al.  The Radioimmunoassay of Testosterone, 5α-Dihydrotestosterone and Their Precursors in the Human Testis , 1978 .

[11]  J. Wilson,et al.  Studies on the regulation of testosterone synthesis in the fetal rabbit testis. , 1978, Endocrinology.

[12]  G. Hammond,et al.  Automation of radioimmunoassays for some sex steroids with use of both iodinated and tritiated ligands. , 1977, Clinical chemistry.

[13]  A. Ruokonen,et al.  The simultaneous radioimmunoassay of seven steroids in human spermatic and peripheral venous blood. , 1977, The Journal of clinical endocrinology and metabolism.

[14]  I. Huhtaniemi,et al.  HCG binding and stimulation of testosterone biosynthesis in the human fetal testis. , 1977, The Journal of clinical endocrinology and metabolism.

[15]  S. Takagi,et al.  Sex differences in fetal gonadotropins and androgens. , 1977, Journal of steroid biochemistry.

[16]  R. Picon.  Testosterone secretion by foetal rat testes in vitro. , 1976, The Journal of endocrinology.

[17]  J. Clements,et al.  Studies on human sexual development. III. Fetal pituitary and serum, and amniotic fluid concentrations of LH, CG, and FSH. , 1976, The Journal of clinical endocrinology and metabolism.

[18]  D. Apter,et al.  Simultaneous determination of five sex hormones in human serum by radioimmunoassay after chromatography on Lipidex-5000. , 1976, Clinical chemistry.

[19]  I. Huhtaniemi.  Metabolism of pregnenolone and pregnenolone sulphate in human foetal liver tissue in vitro. , 1974, Acta endocrinologica.

[20]  B. Murphy,et al.  Androgens in the human fetus , 1974 .

[21]  O. Jänne,et al.  Assay of testosterone, progesterone and 17alpha-hydroxyprogesterone in human plasma by radioimmunoassay after separation on hydroxyalkoxypropyl sephadex. , 1974, Journal of steroid biochemistry.

[22]  I. Huhtaniemi.  Endogenous neutral steroids in the lung tissue of early and mid-term human foetuses and in vitro studies on their formation. , 1974, Acta endocrinologica.

[23]  J. Wilson,et al.  Testosterone formation and metabolism during male sexual differentiation in the human embryo. , 1974, The Journal of clinical endocrinology and metabolism.

[24]  I. Huhtaniemi.  Formation of neutral steroids from endogenous precursors in minced human fetal adrenals in vitro. , 1974, Steroids.

[25]  J. Winter,et al.  Studies on human sexual development. I. Fetal gonadal and adrenal sex steroids. , 1973, The Journal of clinical endocrinology and metabolism.

[26]  J. Perchellet,et al.  Studies on sex differentiation in mammals. , 1973, Recent progress in hormone research.

[27]  T. Shepard,et al.  Weight standards for organs from early human fetuses , 1971, The Anatomical record.

[28]  I. Huhtaniemi,et al.  Presence of testosterone and other neutral steroids in human fetal testes. , 1970, Biochemical and biophysical research communications.

[29]  P. Hall,et al.  The action of human chorionic gonadotrophin in vivo upon microsomal enzymes of immature rat testis. , 1967, Biochimica et biophysica acta.

[30]  L. Samuels,et al.  THE INFLUENCE O F CHORIONIC GONADOTROPIN ON THE 3β-OL DEHYDROGENASE ACTIVITY OF TESTES AND ADRENALS1 , 1956 .