Ontogeny of 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) in human testis as studied by immunocytochemistry.
The enzyme complex 3 beta-hydroxy-5-ene-steroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) is involved in the biosynthesis of all classes of active steroids, including androgens. To correlate possible changes in 3 beta-HSD with the well-known variations in testosterone secretion during development, the authors localized this enzyme by immunocytochemistry during fetal and postnatal periods of development in the human testis. In the fetal testis, 3 beta-HSD was detected in Leydig cells during the second and third trimester of gestation. In 8-month-old and 11-year-old boys, however, no immunoreaction could be detected in the testis. In pubertal boys, Leydig cells appeared well developed and immunopositive. Since the fluctuations in 3 beta-HSD immunoreactivity are similar to those already observed for androgen secretion, activation of 3 beta-HSD by trophic hormones may play an important role in androgen production during fetal and postnatal development.
Dupont
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MRC Group in Molecular Endocrinology, CHUL Research Center and Laval University, Québec, Canada.
Luu-The
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Labrie
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F
Pelletier
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G
D000293:Adolescent; D000375:Aging / Q000378:metabolism; D002648:Child; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D007985:Leydig Cells / Q000201:enzymology; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism*; D011375:Progesterone Reductase / Q000378:metabolism*; D013251:Steroid Isomerases / Q000378:metabolism*; D013737:Testis / Q000196:embryology / Q000201:enzymology*
C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D009097:Multienzyme Complexes; D011375:Progesterone Reductase; D013251:Steroid Isomerases