A Δ<sup>4</sup>-3-Keto Pathway for Testosterone Synthesis in the Human Spermatozoa

Gunasegaram, R.; Chew, Peter; Loganath, A.; Peh, K. L.; Ratnam, S. S.

doi:10.3109/01485019808987927

Cited by 17 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is important to mention that the human spermatozoa produce oestrogens (Gunasegaram et al 1995) and indeed they express a functional aromatase that is still active after ejaculation ; together with the presence of ERs (Aquila et al 2004;Luconi et al 2004;Solakidi et al 2005), these data open new considerations about the role of oestrogens all along the male genital tract and likely also regarding sperm mobility and fertilization ability. Indeed, Fraser et al (2006) have demonstrated that either oestradiol or a phytoestrogen (genistein) improves the capacitation and acrosome loss of human spermatozoa.…”

Section: For Reviews)mentioning

confidence: 99%

“…In humans, Leydig cells (Payne et al 1976) and Sertoli cells produce oestrogens (Foucault et al 1992;see Carreau 1996see Carreau , 2007 for reviews) and spermatozoa can metabolize pregnenolone into oestrogens (Gunasegaram et al 1995). Taking into account the presence of aromatase in rodent testis and the probable role of oestrogens in spermatogenesis (see Carreau et al 1999 andHess 2003 for reviews), we have checked the expression of aromatase in motile and immotile spermatozoa from healthy donors and studied the relevance of this protein to sperm quality (motility and survival).…”

Section: Aromatase and Oestrogen Receptors In Human Testicular Cells mentioning

confidence: 99%

See 1 more Smart Citation

Aromatase, oestrogens and human male reproduction

Carreau

Wołczyński

Galeraud-Denis

2010

Phil. Trans. R. Soc. B

103

View full text Add to dashboard Cite

In most mammalian species aromatase is encoded by a single gene (Cyp19), which contains 18 exons, nine of them being translated. In man, the presence of a biologically active aromatase and oestrogen receptors (ERa and ERb) has been reported in Leydig cells, and also in immature germ cells and ejaculated spermatozoa. Concerning aromatase, the amount of transcript and enzymatic activity are decreased in immotile compared with motile sperm. We have amplified aromatase mRNA by real-time polymerase chain reaction in spermatozoa from asthenospermic, teratospermic and asthenoteratospermic men and recorded, respectively, 44, 52 and 67 per cent decreases of the amount of transcripts compared with fertile donors. A high degree of correlation (r ¼ 20.64) between the abnormal spermatozoa (especially microcephaly and acrosome malformations) and aromatase/GAPDH transcript ratio has been observed. Idiopathic infertility is a wide health problem and no treatment is currently available. In humans, even if the role of oestrogens in spermatogenesis is still a matter of debate, the observations of decreased sperm number and motility in men genetically deficient in aromatase, together with our data and those reported in the literature, may suggest a role for aromatase/oestrogens not only during the development and maintenance of spermatogenesis but also in the final maturation of spermatozoa.

show abstract

Section: For Reviews)mentioning

confidence: 99%

Section: Aromatase and Oestrogen Receptors In Human Testicular Cells mentioning

confidence: 99%

Aromatase, oestrogens and human male reproduction

Carreau

Wołczyński

Galeraud-Denis

2010

Phil. Trans. R. Soc. B

103

View full text Add to dashboard Cite

show abstract

“…These include the hydrolysis of major sterol sulfates such as cholesteryl and demosterol sulfates [ 5 ] , cholesterol derived from the uptake of lipoproteins by endocytotic processes, intake of precursor steroids via specific membrane receptors [ 11 and synthesis de novo [8]. Specifically, we asked whether de novo synthesis and metabolism of We have also characterized in the sperm a A4-3-keto route of testosterone formation with pregnenolone as substrate [7]. In the present study we provide evidence of testosterone biosynthesis by a A5-3p-hydroxy pathway.…”

Section: Resultsmentioning

confidence: 99%

Characterization of a Δ⁵-3β-Hydroxy Pathway of Testosterone Synthesis in the Human Spermatozoa

Gunasegaram

Loganath

Peh

et al. 1997

Archives of Andrology

Self Cite

View full text Add to dashboard Cite

“…30). It has also been claimed that spermatozoa can convert pregnenolone into estrogens (31). After obtaining data on the expression of aromatase in male germ cells of the rat, we decided to check for the presence of aromatase in ejaculated spermatozoa from healthy donors.…”

Section: Aromatase In Primate Testesmentioning

confidence: 99%

Estrogens and male reproduction: a new concept

Carreau

Silandre

Bourguiba

et al. 2007

Braz J Med Biol Res

View full text Add to dashboard Cite

The mammalian testis serves two main functions: production of spermatozoa and synthesis of steroids; among them estrogens are the end products obtained from the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase. The aromatase is encoded by a single gene (cyp19) in humans which contains 18 exons, 9 of them being translated. In rats, the aromatase activity is mainly located in Sertoli cells of immature rats and then in Leydig cells of adult rats. We have demonstrated that germ cells represent an important source of estrogens: the amount of P450arom transcript is 3-fold higher in pachytene spermatocytes compared to gonocytes or round spermatids; conversely, aromatase activity is more intense in haploid cells. Male germ cells of mice, bank voles, bears, and monkeys express aromatase. In humans, we have shown the presence of a biologically active aromatase and of estrogen receptors (α and ß) in ejaculated spermatozoa and in immature germ cells in addition to Leydig cells. Moreover, we have demonstrated that the amount of P450arom transcripts is 30% lower in immotile than in motile spermatozoa. Alterations of spermatogenesis in terms of number and motility of spermatozoa have been described in men genetically deficient in aromatase. These last observations, together with our data showing a significant decrease of aromatase in immotile spermatozoa, suggest that aromatase could be involved in the acquisition of sperm motility. Thus, taking into account the widespread localization of aromatase and estrogen receptors in testicular cells, it is obvious that, besides gonadotrophins and androgens, estrogens produced locally should be considered to be physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis.

show abstract

A Δ⁴-3-Keto Pathway for Testosterone Synthesis in the Human Spermatozoa

Cited by 17 publications

References 17 publications

Aromatase, oestrogens and human male reproduction

Aromatase, oestrogens and human male reproduction

Characterization of a Δ⁵-3β-Hydroxy Pathway of Testosterone Synthesis in the Human Spermatozoa

Estrogens and male reproduction: a new concept

Contact Info

Product

Resources

About

A Δ4-3-Keto Pathway for Testosterone Synthesis in the Human Spermatozoa

Cited by 17 publications

References 17 publications

Aromatase, oestrogens and human male reproduction

Aromatase, oestrogens and human male reproduction

Characterization of a Δ5-3β-Hydroxy Pathway of Testosterone Synthesis in the Human Spermatozoa

Estrogens and male reproduction: a new concept

Contact Info

Product

Resources

About

A Δ⁴-3-Keto Pathway for Testosterone Synthesis in the Human Spermatozoa

Characterization of a Δ⁵-3β-Hydroxy Pathway of Testosterone Synthesis in the Human Spermatozoa