Alkaline phosphatase in stallion semen: characterization and clinical applications.
Abstract: Significant amounts of alkaline phosphatase (AP) activity have been found in semen plasma from numerous species. In species in which the majority of semen plasma AP (SPAP) activity originates from the epididymis and testicle, SPAP activity can be used clinically as a marker to differentiate testicular origin azoospermia or oligospermia from ejaculatory failure. Information on SPAP activity in stallions to date has been limited. In this study, a standard clinical chemistry analyzer was used to determine AP activity in pre-ejaculatory fluid and ejaculates from groups of normal stallions. Additionally, accessory glands, epididymides, testicles and other components of the urogenital tract of normal stallions were assayed to determine which tissues contain SPAP activity. The results indicated that levels of AP activity are low in pre-ejaculatory fluid, but significantly higher in ejaculatory fluid from normal stallions. Spermatozoa were not a significant source of SPAP activity. High levels of SPAP activity were found in the testes and epididymides. These findings suggest that SPAP activity is a candidate for a sperm-independent marker for ejaculation in the stallion. Finally, AP activity was determined in ejaculatory fluid from a stallion with bilaterally blocked ampullae, both before and after relief of the blockage. While the blockage was present, AP activity in ejaculatory fluid was low. However, following relief of the blockage, AP activity in ejaculatory fluid rose dramatically, thus suggesting that AP activity will be useful as an inexpensive, simple clinical assay for differentiating ejaculatory failure or excurrent duct blockages from testicular origin azoospermia and oligospermia.
Publication Date: 2003-03-07 PubMed ID: 12620574DOI: 10.1016/s0093-691x(02)00956-1Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Animal Science
- Clinical Findings
- Clinical Pathology
- Clinical Study
- Diagnosis
- Diagnostic Technique
- Disease Diagnosis
- Equid Semen
- Equine Health
- Equine Science
- Horse Breeds
- Phosphatase
- Reproduction
- Spermatogenesis
- Stallion
- Testes
- Veterinary Care
- Veterinary Medicine
- Veterinary Practice
- Veterinary Research
- Veterinary Science
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research is about the detection of Alkaline Phosphatase (AP) in stallion semen, its characteristics, and potential clinical applications. It suggests that AP activity in semen could be used to determine issues related to ejaculatory failure or blockages in the reproductive tract.
Characterization of Alkaline Phosphatase in Stallion Semen
- The study measured the activity of Alkaline Phosphatase (AP), an enzyme found in the semen plasma of many species, in the semen of stallions.
- By using a common clinical chemistry analyzer, the researchers measured AP activity in both pre-ejaculatory fluid and ejaculates from a group of healthy stallions.
- It was observed that AP activity was invariably low in pre-ejaculatory fluid but notably higher in ejaculatory fluid.
- The researchers also found that spermatozoa (sperm cells) were not a significant source of AP in semen plasma (SPAP).
Source of Alkaline Phosphatase Activity
- Various components of the stallion’s urogenital tract, such as the accessory glands, testicles, and epididymides, were also examined to identify which tissues contribute to SPAP activity.
- High levels of SPAP activity were particularly observed in the testes and epididymides, indicating that these locations may be the main source of AP in the semen.
- The colleted results suggest SPAP activity as a potential sperm-independent signal of ejaculation in the stallion.
Potential Clinical Uses of Alkaline Phosphatase Activity
- The study examined an exceptional case of a stallion with a bilateral blockage in the ampullae, a widened section of each vas deferens where it joins the urethra, both before and after mitigating the blockage.
- This showed that the AP activity in the ejaculatory fluid was low while the blockage was present but significantly increased once the blockage was relieved.
- These findings suggest that the AP activity in the semen could be a reliably cheap and easy clinical test to differentiate between ejaculatory failure or blockage in the excurrent ducts and azoospermia (absence of sperm in semen) or oligospermia (low sperm count), that originate from the testicles.
In conclusion, this study affirms the significant presence of Alkaline Phosphatase in stallion semen and its potential as a clinical marker relating to the ejaculatory function and health of their reproductive tract.
Cite This Article
APA
Turner RM, McDonnell SM.
(2003).
Alkaline phosphatase in stallion semen: characterization and clinical applications.
Theriogenology, 60(1), 1-10.
https://doi.org/10.1016/s0093-691x(02)00956-1 Publication
Researcher Affiliations
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA 19348-1692, USA. rmturner@vet.upenn.edu
MeSH Terms
- Alkaline Phosphatase / metabolism
- Animals
- Constriction, Pathologic / enzymology
- Constriction, Pathologic / veterinary
- Ejaculation
- Ejaculatory Ducts / pathology
- Genitalia, Male / enzymology
- Horse Diseases / enzymology
- Horses / physiology
- Male
- Oligospermia / enzymology
- Oligospermia / veterinary
- Semen / enzymology
- Sperm Count
Citations
This article has been cited 13 times.- Goericke-Pesch S, Reifarth L, Behrens Mathiesen C, Schuler G, Umbach AK, Körber H. Chronic Immune-Mediated Orchitis Is the Major Cause of Acquired Non-obstructive Azoospermia in Dogs. Front Vet Sci 2022;9:865967.
- Cecchini Gualandi S, Giangaspero B, Di Palma T, Macchia G, Carluccio A, Boni R. Oxidative profile and protease regulator potential to predict sperm functionality in donkey (Equus asinus). Sci Rep 2021 Oct 15;11(1):20551.
- Ebel F, Ulloa O, Strobel P, Ramírez-Reveco A. Semen Quality and Freezability Analyses in the Ejaculates of Two Poitou Donkeys in the Southern Hemisphere. Front Vet Sci 2021;8:662887.
- Bucci D, Spinaci M, Galeati G, Tamanini C. Different approaches for assessing sperm function. Anim Reprod 2020 May 22;16(1):72-80.
- Alamaary MS, Haron AW, Hiew MWH, Ali M. Effects of cysteine and ascorbic acid in freezing extender on sperm characteristics and level of enzymes in post-thawed stallion semen. Vet Med Sci 2020 Nov;6(4):666-672.
- Alboghobeish S, Mahdavinia M, Zeidooni L, Samimi A, Oroojan AA, Alizadeh S, Dehghani MA, Ahangarpour A, Khorsandi L. Efficiency of naringin against reproductive toxicity and testicular damages induced by bisphenol A in rats. Iran J Basic Med Sci 2019 Mar;22(3):315-523.
- Talluri TR, Mal G, Ravi SK. Biochemical components of seminal plasma and their correlation to the fresh seminal characteristics in Marwari stallions and Poitou jacks. Vet World 2017 Feb;10(2):214-220.
- Kiso WK, Selvaraj V, Nagashima J, Asano A, Brown JL, Schmitt DL, Leszyk J, Travis AJ, Pukazhenthi BS. Lactotransferrin in Asian elephant (Elephas maximus) seminal plasma correlates with semen quality. PLoS One 2013;8(8):e71033.
- Clements KM, Shipley CF, Coleman DA, Ehrhart EJ, Haschek WM, Clark SG. Azoospermia in an 8-month-old boar due to bilateral obstruction at the testis/epididymis interface. Can Vet J 2010 Oct;51(10):1130-4.
- Gray GA, Dascanio JJ, Kasimanickam R, Sponenberg DP. Bilateral epidiymal cysts in an alpaca male used for breeding. Can Vet J 2007 Jul;48(7):741-4.
- Dissanayake WMN, Gamage MAGNDMA, Heo JM, Yi YJ. Control of alkaline phosphatase activity and pH stability by taurine in liquid boar semen. J Anim Sci Technol 2025 Nov;67(6):1228-1241.
- Ömür AD, Uçak G, Kara A, Erbaş E, Akarsu SA, Özkanlar S, Celep NA. Evaluating the Potential Adverse Effects of Favipiravir on Biochemical, Histopathological, and Spermatological Parameters in Male Rats' Testicular Tissue. J Biochem Mol Toxicol 2025 Jun;39(6):e70331.
- Bucci R, Parrillo S, Probo M, Varasano V, Romano A, Carluccio A. Case Report: Reproductive evaluation of a Murgese stallion with obstructive azoospermia, accumulation of hyaline material in the ampullae ducts, and corpora amylacea in vesicular glands. Front Vet Sci 2025;12:1571637.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
