Differential regulation of steroidogenic enzymes metabolizing testosterone or dihydrotestosterone by human chorionic gonadotropin in cultured rat neonatal interstitial cells

1990 ◽  
Vol 122 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Eisuke P. Murono
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
Differential Regulation ◽  
Steroidogenic Enzyme ◽  
Isomerase Activity ◽  
Adult Leydig Cells

Abstract The present studies examined the effects of hCG on steroidogenic enzyme activities involved in the metabolism of testosterone or dihydroststosterone in cultured rat neonatal interstitial cells. 5α-reductase and 17β-hydroxysteroid dehydrogenase activities, which are involved in the conversion of testosterone to dihydrotestosterone and androstenedione, respectively, were low in cultured neonatal interstitial cells, were unresponsive to hCG and declined to undetectable levels during 14 days of culture. However, Δ5-3β-hydroxysteroid dehydrogenase-isomerase activity, which is involved in the biosynthesis of testosterone, and 5α-androstane-3α-hydroxysteroid dehydrogenase and 5α-androstane-3β-hydroxysteroid dehydrogenase activities, which are involved in the conversion of dihydrotestosterone to 5α-androstan-3α, 17β-diol and 5α-androstan-3β, 17β-diol, respectively, were maintained or increased by hCG during the same culture period. These results demonstrate that 5α-reductase and 17β-hydroxysteroid dehydrogenase activities do not play a significant role in regulating testosterone accumulation in fetal/neonatal Leydig cells, and they suggest that these cells are adapted to maintain high testosterone but low dihydrotestosterone levels. The present results demonstrate also that fetal/neonatal Leydig cells differ from immature or adult Leydig cells with respect to the sensitivity of 5α-reductase activity to LH/hCG.

scholarly journals Cyclooxygenase-2 and Prostaglandin F2α in Syrian Hamster Leydig Cells: Inhibitory Role on Luteinizing Hormone/Human Chorionic Gonadotropin-Stimulated Testosterone Production

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4476-4485 ◽  
Author(s):  
Mónica B. Frungieri ◽  
Silvia I. Gonzalez-Calvar ◽  
Fernanda Parborell ◽  
Martin Albrecht ◽  
Artur Mayerhofer ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Syrian Hamster ◽  
Leydig Cells ◽  
Regulatory Protein ◽  
Hydroxysteroid Dehydrogenase ◽  
Steroidogenic Acute Regulatory Protein ◽  
Testosterone Production ◽  
Cox 2 ◽  
Steroidogenic Acute Regulatory

We have previously found that cyclooxygenase-2 (COX-2), a key enzyme in the biosynthesis of prostaglandins (PGs), is present in the testicular interstitial cells of infertile men, whereas it is absent in human testes with no evident morphological changes or abnormalities. To find an animal model for further investigating COX-2 and its role in testicular steroidogenesis, we screened testes from adult species ranging from mice to monkeys. By using immunohistochemical assays, we found COX-2 expression only in Leydig cells of the reproductively active (peripubertal, pubertal, and adult) seasonal breeder Syrian hamster. COX-2 expression in hamster Leydig cells was confirmed by RT-PCR. In contrast, COX-1 expression was not detected in hamster testes. Because COX-2 expression implies PG synthesis, we investigated the effect of various PGs on testosterone production and found that PGF2α stood out because it significantly reduced human chorionic gonadotropin-stimulated testosterone release from isolated hamster Leydig cells in a dose-dependent manner. This mechanism involves a decreased expression of testicular steroidogenic acute regulatory protein and 17β-hydroxysteroid dehydrogenase. Testicular concentration and content of PGF2α in reproductively active hamsters as well as production of PGF2α from isolated hamster Leydig cells were also determined. Moreover, PGF2α receptors were localized in Leydig cells of hamsters and testicular biopsies from patients with Sertoli cell only and germ arrest syndromes. Thus, in this study, we described a COX-2-initiated pathway that via PGF2α production, PGF2α receptors, steroidogenic acute regulatory protein, and 17β-hydroxysteroid dehydrogenase represents a physiological local inhibitory system of human chorionic gonadotropin-stimulated testosterone production in the Syrian hamster testes.

Maturational changes in steroidogenic enzyme activities metabolizing testosterone and dihydrotestosterone in two populations of testicular interstitial cells

1989 ◽  
Vol 121 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Eisuke P. Murono
Keyword(s):  
Enzyme Activities ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
Band 3 ◽  
Steroidogenic Enzyme ◽  
Testicular Interstitial Cells ◽  
Changing Patterns ◽  
Low Levels ◽  
Two Populations

Abstract. The present study examined changes in steroidogenic enzyme activities which metabolize testosterone or dihydrotestosterone between days 21–73 of maturation in Band 2 and Band 3 cells isolated by centrifugation of rat testicular interstitial cells on metrizamide density gradients. 5α-reductase and 17β-hydroxysteroid dehydrogenase activities increased progressively in Band 2 and Band 3 cells between days 21–35 of maturation, then both enzyme activities declined to reach low levels in adult Band 2 and Band 3 cells. The significantly higher activities of both enzymes in Band 3, which contains a greater concentration of Leydig cells at each age, suggest their localization in Leydig cells. 5α-androstane-3α- and 3β-hydroxysteroid dehydrogenase activities increased in both Band 2 and Band 3 cells between days 21–50 of maturation and remained elevated; however, dihydrotestosterone was metabolized primarily to 5α-androstane-3α,17β-diol in Band 2 cells, while 5α-androstane-3β,17β-diol was the major metabolite of dihydrotestosterone in Band 3 cells. These studies suggest that testosterone accumulation during sexual maturation can be influenced by changing patterns of 5α-reductase and 17β-hydroxysteroid dehydrogenase activities which metabolize testosterone, and of 5α-androstane-3α- and 3β-hydroxysteroid dehydrogenase activities which metabolize dihydrotestosterone in both Band 2 and Band 3 cells.

Sign in / Sign up

Export Citation Format

Share Document