Immunocytochemical localization of cytochrome P450 aromatase in the testis of prepubertal, pubertal, and postpubertal horses.
Abstract: The large amount of testicular estrogens produced by the stallion is unique compared to the amounts found in other domestic species. Although the cellular locale of the cytochrome P450 aromatase (P450arom) enzyme that converts C19 androgens to C18 estrogens has been identified in the Leydig cell of adult equine testis, the location in the immature equine testis is not known. The goal of this work was to localize the enzyme in colts and stallions during sexual development. Testes were obtained from prepubertal (n=7), pubertal (n=6), and postpubertal (n=8) colts and stallions during both the breeding and non-breeding seasons. Tissue was fixed and prepared for immunocytochemistry (ICC), carried out with an antiserum against human placental P450arom. In prepubertal colts, there was distinct immunopositive staining of a similar degree within both the Leydig cell and the seminiferous tubule. Horses in the pubertal group had strong Leydig cell immunopositive staining and a slight degree of positive staining within the seminiferous tubules. Postpubertal stallions exhibited definitive immunopositive staining within Leydig cells but not within the seminiferous tubules. Therefore, P450arom is present within the Leydig cell throughout sexual development. In contrast, the presence of P450arom within the seminiferous tubule based upon ICC appeared to be gone by adulthood, suggesting that an age-dependent shift in the locale of this enzyme as the stallion matures.
Publication Date: 2003-12-10 PubMed ID: 14662129DOI: 10.1016/s0093-691x(03)00237-1Google Scholar: Lookup
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- Journal Article
Summary
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This research article investigates the localization of the enzyme cytochrome P450 aromatase in the testes of horses at different stages of sexual maturity. The enzyme is known to be responsible for converting androgens to estrogens, with its presence in adult horse testes previously identified. The study aims to locate the enzyme in both immature and maturing horses, with results suggesting a shift in enzyme localization with age.
Objective of the Research
- The research sought to determine the presence and location of the enzyme cytochrome P450 aromatase in the testes of horses during various stages of sexual development.
- The focus was on prepubertal, pubertal, and postpubertal horses, sampled during both breeding and non-breeding seasons.
- The enzyme’s known function is the conversion of androgens to estrogens. It had been previously identified in adult horse testes but its location in immature horse testes remained unclear.
Methodology
- Testes were collected from a total of 21 horses: 7 prepubertal, 6 pubertal, and 8 postpubertal.
- The tissues were then prepared for immunocytochemistry (ICC), a technique used to visualize specific proteins in cells, using an antiserum against human placental P450arom.
Findings
- In prepubertal colts, both the Leydig cell and the seminiferous tubule showed distinct and similar degrees of immunopositive staining, indicating the presence of P450arom.
- The pubertal group showed strong presence of the enzyme within the Leydig cells, and a slight degree of presence within the seminiferous tubules.
- Postpubertal stallions exhibited definite presence of the enzyme within the Leydig cells, but not within the seminiferous tubules.
- The results suggest that although the P450arom enzyme is consistently present within the Leydig cells throughout sexual development, its presence within the seminiferous tubule seems to cease by the postpubertal stage.
Conclusion and Implications
- The research inferred an age-dependent shift in the localization of the enzyme cytochrome P450 aromatase in the testes of horses, having implications for our understanding of hormone production and regulation in these animals.
- This knowledge could potentially enhance current understanding of sexual maturation in horses, which in turn might help improve breeding management and other related sectors.
Cite This Article
APA
Hess MF, Roser JF.
(2003).
Immunocytochemical localization of cytochrome P450 aromatase in the testis of prepubertal, pubertal, and postpubertal horses.
Theriogenology, 61(2-3), 293-299.
https://doi.org/10.1016/s0093-691x(03)00237-1 Publication
Researcher Affiliations
- Department of Animal Science, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
MeSH Terms
- Animals
- Aromatase / analysis
- Horses / growth & development
- Immunohistochemistry
- Leydig Cells / enzymology
- Male
- Seminiferous Tubules / enzymology
- Sexual Maturation
- Testis / enzymology
- Testis / growth & development
Citations
This article has been cited 9 times.- Han M, Liang C, Liu Y, He X, Chu M. Integrated Transcriptome Analysis Reveals the Crucial mRNAs and miRNAs Related to Fecundity in the Hypothalamus of Yunshang Black Goats during the Luteal Phase. Animals (Basel) 2022 Dec 2;12(23).
- Shakeel M, Yoon M. Functions of somatic cells for spermatogenesis in stallions. J Anim Sci Technol 2022 Jul;64(4):654-670.
- Zhang Y, Chen X, Zhou Z, Tian X, Yang P, Fu K. CYP19A1 May Influence Lambing Traits in Goats by Regulating the Biological Function of Granulosa Cells. Animals (Basel) 2022 Jul 27;12(15).
- Ellerbrock RE, Podico G, Scoggin KE, Ball BA, Carossino M, Canisso IF. Steroidogenic Enzyme and Steroid Receptor Expression in the Equine Accessory Sex Glands. Animals (Basel) 2021 Aug 6;11(8).
- Nurliani A, Sasaki M, Budipitojo T, Tsubota T, Suzuki M, Kitamura N. An immunohistochemical study on testicular steroidogenesis in the Sunda porcupine (Hystrix javanica). J Vet Med Sci 2019 Sep 3;81(9):1285-1290.
- Cooke PS, Nanjappa MK, Ko C, Prins GS, Hess RA. Estrogens in Male Physiology. Physiol Rev 2017 Jul 1;97(3):995-1043.
- Li Q, Zhang F, Zhang S, Sheng X, Han X, Weng Q, Yuan Z. Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt). Eur J Histochem 2015 Feb 17;59(1):2456.
- Dhakal P, Tsunoda N, Nakai R, Nagaoka K, Nambo Y, Sato F, Taniyama H, Taya K. Post-Natal Dynamic Changes in Circulating Follicle-Stimulating Hormone, Luteinizing Hormone, Immunoreactive Inhibin, Progesterone, Testosterone and Estradiol-17β in Thoroughbred Colts until 6 Months of Age. J Equine Sci 2011;22(1):9-15.
- Carreau S, Hess RA. Oestrogens and spermatogenesis. Philos Trans R Soc Lond B Biol Sci 2010 May 27;365(1546):1517-35.
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