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Journal of equine science2014; 25(2); 45-52; doi: 10.1294/jes.25.45

Histopathological characteristics of endometrosis in thoroughbred mares in Japan: results from 50 necropsy cases.

Abstract: Uteri from 50 necropsied nonpregnant Japanese Thoroughbred brood mares (1-30 years of age) were investigated to clarify the histopathological characteristics of endometrosis in Japanese Thoroughbred mares and the distribution pattern of endometrosis lesions in the uterus as a whole. Endometrosis was observed in all animals over 6 years of age and in all of the 21 mares aged over 12 years of age. The affected mares showed elastofibrosis of arteries, veins and lymphatic vessels in the uterine wall, atrophy of the uterine smooth muscle layers and hyperplasia of collagen fibers among the smooth muscle fascicles of the myometrium, in addition to pathomorphologic features of endometrosis such as stromal endometrial fibrosis accompanied by endometrial atrophy, periglandular fibrosis and reduction of uterine glands. The severity of the histopathological changes increased with advancing age. Lymphatic vessels with elastofibrosis showed marked lymph congestion, leading to lymphatic edema. With increasing age, the extent of the distribution of these lesions tended to expand from focal to diffuse involvement of the entire uterus. Based on these findings, we speculate that aging plays a role in the pathogenesis of endometrosis; circulatory disturbances due to intrauterine angiosis or angiopathy, particularly reduction of the arterial blood supply and disturbance of venous drainage, resulting in a reduction of lymphatic drainage (lymphatic edema), are closely related to the onset and progression of endometrial fibrosis and myometrial atrophy with fibroplasia may result in myometrial hypofunction during the peri-implantation or puerperal period.
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Publication Date: 2014-06-25 PubMed ID: 25013358PubMed Central: PMC4090358DOI: 10.1294/jes.25.45Google Scholar: Lookup
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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 study investigates the histopathological features of endometrosis in Japanese Thoroughbred mares. This condition was found in all examined animals over the age of 6, and its severity increased with age. The study suggests that age-related circulatory disturbances contribute significantly to the onset and advancement of endometrosis.

Research Context

  • The study focuses on examining the histopathological characteristics of endometrosis in nonpregnant Thoroughbred mares in Japan. Endometrosis, a disorder characterized by fibrotic changes in the endometrium (the inner lining of the uterus), is associated with suboptimal fertility in horses.
  • The evaluation was carried out using the uteri of 50 mares, aged from 1 to 30 years, which were necropsied (autopsied).

Main Findings

  • Endometrosis was observed in every animal aged over six years and all 21 mares more than 12 years old.
  • Pathological changes in affected mares included a series of alterations in the uterus. These included elastofibrosis of the arteries, veins, and lymphatic vessels, hyperplasia of collagen fibers in the myometrium (muscle layer of the uterus), stromal endometrial fibrosis along with endometrial atrophy, periglandular fibrosis, and reduction in uterine glands.
  • Lymphatic vessels affected by elastofibrosis showed significant lymph congestion, leading to lymphatic edema.
  • Severity of changes increased as mares got older. In elder mares, lesions expanded from focal to a more diffuse presence affecting the entire uterus.

Conclusions and Speculations

  • The research points to aging as a major role player in the onset of endometrosis.
  • Furthermore, circulatory disturbances are found to be intimately associated with the onset and progression of the condition. Particularly, reduction in arterial blood supply and disturbances of venous drainage, leading to constraints in lymphatic drainage (lymphatic edema) could be crucial.
  • The study suggests that these changes could lead to endometrial fibrosis and myometrial atrophy. This may ultimately result in myometrial hypofunction during the peri-implantation or puerperal period, possibly explaining reduced fertility observed in mares diagnosed with endometrosis.

Cite This Article

APA
Hanada M, Maeda Y, Oikawa MA. (2014). Histopathological characteristics of endometrosis in thoroughbred mares in Japan: results from 50 necropsy cases. J Equine Sci, 25(2), 45-52. https://doi.org/10.1294/jes.25.45

Publication

Journal of equine science
ISSN: 1340-3516
NlmUniqueID: 9503751
Country: Japan
Language: English
Volume: 25
Issue: 2
Pages: 45-52

Researcher Affiliations

Hanada, Michiko
  • Faculty of Animal Health Technology, Department of Animal Health Technology, Yamazaki Gakuen University, Tokyo 150-0046, Japan.
Maeda, Yousuke
  • Laboratory of Large Animal Medicine, School of Veterinary Medicine, Kitasato University, Aomori 034-8628, Japan ; Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Florida 32610, USA.
Oikawa, Masa-Aki
  • Misawa Air Base Veterinary Clinic, US Army Public Health Command-Japan, APO, AP96319, Japan ; Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.

References

This article includes 28 references
  1. . Proceedings of the John P. Hughes International Workshop on Equine Endometritis. Davis, California, August 1992.. Equine Vet J 1993 May;25(3):184-93.
    pubmed: 8508744doi: 10.1111/j.2042-3306.1993.tb02940.xgoogle scholar: lookup
  2. Dybdal N.O., Daels P.F., Couto M.A., Hughes J.P., Kennedy P.C.. Investigation of the reliability of a single endometrial biopsy sample, with a note on the correlation between uterine cysts and biopsies grade.. J. Reprod. Fertil. Suppl. 1999;44:697.
  3. Flores J.M., Rodoriguez A., Sanchez J., Gomez-Cuetara C., Ramiro F.. Endometrosis in mares: incidence of histopathological alterations.. Reprod. Domest. Anim. 1995;30:61–65.
  4. Grüninger B, Schoon HA, Schoon D, Menger S, Klug E. Incidence and morphology of endometrial angiopathies in mares in relationship to age and parity.. J Comp Pathol 1998 Oct;119(3):293-309.
    pubmed: 9807730doi: 10.1016/s0021-9975(98)80051-0google scholar: lookup
  5. Hoffmann C, Bazer FW, Klug J, Aupperle H, Ellenberger C, Schoon HA. Immunohistochemical and histochemical identification of proteins and carbohydrates in the equine endometrium Expression patterns for mares suffering from endometrosis.. Theriogenology 2009 Jan 15;71(2):264-74.
    pubmed: 18762329doi: 10.1016/j.theriogenology.2008.07.008google scholar: lookup
  6. Hoffmann C, Ellenberger C, Mattos RC, Aupperle H, Dhein S, Stief B, Schoon HA. The equine endometrosis: new insights into the pathogenesis.. Anim Reprod Sci 2009 Apr;111(2-4):261-78.
    pubmed: 18468817doi: 10.1016/j.anireprosci.2008.03.019google scholar: lookup
  7. Inoue Y., Ito K., Terada T., Nishimura N., Hatozoe T., Sato K.. Degenerative changes in the endometrial vasculature of the mare detected by videoendoscopic examination.. Proc. Am. Assoc. Equine Pract. 2000;46:325–329.
  8. Kamiya S, Daigo M. Relationship between glycosaminoglycans and pregnancy-induced sclerosis in bovine uterine arteries.. Nihon Juigaku Zasshi 1988 Oct;50(5):1055-9.
    pubmed: 3199613doi: 10.1292/jvms1939.50.1055google scholar: lookup
  9. Keller A., Neves A.P., Aupperle H., Steiger K., Garbade P., Schoon H.-A., Klug E., Mattos R.C.. Repetitive experimental bacterial infections do not affect the degree of uterine degeneration in the mare.. Anim. Reprod. Sci. 2006;94:276–279.
  10. Kenney RM, Ganjam VK. Selected pathological changes of the mare uterus and ovary.. J Reprod Fertil Suppl 1975 Oct;(23):335-9.
    pubmed: 1060802
  11. Kenney RM. Cyclic and pathologic changes of the mare endometrium as detected by biopsy, with a note on early embryonic death.. J Am Vet Med Assoc 1978 Feb 1;172(3):241-62.
    pubmed: 621166
  12. Kenney R.M., Doig P.A.. Equine endometrial biopsy.. 1986;pp. 723–729. In: Current Therapy in Theriogenology. (Morrow, D.A. ed.), W.B. Saunders, Philadelphia..
  13. Lehmann J, Ellenberger C, Hoffmann C, Bazer FW, Klug J, Allen WR, Sieme H, Schoon HA. Morpho-functional studies regarding the fertility prognosis of mares suffering from equine endometrosis.. Theriogenology 2011 Oct 15;76(7):1326-36.
    pubmed: 21855986doi: 10.1016/j.theriogenology.2011.06.001google scholar: lookup
  14. Ludwig S., Schoon D., Aupperle H., von Reiswitz A., Schoon H.-A.. Angiopathies in the equine endometrial biopsy-a marker for extrauterine vascular lesions?. Pferdeheilkunde 2001;17:608–614.
  15. Ludwig S., Blaich U., Schoon D., Aupperle H., Schoon H.-A., Bartmann C.-P., Klug E.. Functional pathology of the uterine blood flow in the mare-pathohistologic and Doppler sonographic investigations.. Theriogenology 2002;58:511–513.
  16. Miyakoshi D., Shikichi M., Ito K., Iwata K., Okai K., Sato F., Nambo Y.. Factors influencing the frequency of pregnancy loss among thoroughbred mares in Hidaka, Japan.. J. Equine Vet. Sci. 2012;32:552–557.
  17. Nambo Y, Oikawa M, Yoshihara T, Kuwano A, Katayama Y. Age-related morphometrical changes of arteries of uterine wall in mares.. Zentralbl Veterinarmed A 1995 Aug;42(6):383-7.
    pubmed: 7495170doi: 10.1111/j.1439-0442.1995.tb00390.xgoogle scholar: lookup
  18. Oikawa M, Katayama Y, Yoshihara T, Kaneko M, Yoshikawa T. Microscopical characteristics of uterine wall arteries in barren aged mares.. J Comp Pathol 1993 May;108(4):411-5.
    pubmed: 8366209doi: 10.1016/s0021-9975(08)80214-9google scholar: lookup
  19. Ricketts SW, Alonso S. The effect of age and parity on the development of equine chronic endometrial disease.. Equine Vet J 1991 May;23(3):189-92.
    pubmed: 1884699doi: 10.1111/j.2042-3306.1991.tb02752.xgoogle scholar: lookup
  20. Rooney J.R., Robertson J.L.. Rupture of the uterine, ovarian, iliac arteries.. 1996;pp. 237–238. In: Equine Pathology. (Rooney, J.R. and Robertson, J.L. eds.), Iowa State University Press, Ames..
  21. Schoon D., Schoon H.-A., Klug E.. Angioses in the equine endometrium-pathogenesis and clinical correlations.. Pferdeheilkunde 1999;15:541–546.
  22. Schoon H.-A., Schoon D.. The category I mare (Kenney and Doig 1986): expected foaling rate 80–90%—fact or fiction?. Pferdeheilkunde 2003;19:698–701.
  23. Troedsson MH, Liu IK. Uterine clearance of non-antigenic markers (51Cr) in response to a bacterial challenge in mares potentially susceptible and resistant to chronic uterine infections.. J Reprod Fertil Suppl 1991;44:283-8.
    pubmed: 1795272
  24. Troedsson MH, Wiström AO, Liu IK, Ing M, Pascoe J, Thurmond M. Registration of myometrial activity using multiple site electromyography in cyclic mares.. J Reprod Fertil 1993 Nov;99(2):299-306.
    pubmed: 8107010doi: 10.1530/jrf.0.0990299google scholar: lookup
  25. Ueno T, Nambo Y, Tajima Y, Umemura T. Pathology of lethal peripartum broad ligament haematoma in 31 Thoroughbred mares.. Equine Vet J 2010 Sep;42(6):529-33.
    pubmed: 20716193doi: 10.1111/j.2042-3306.2010.00090.xgoogle scholar: lookup
  26. Vanderwall D.K., Woods G.L.. Age-related subfertility in the mare.. Proc. Am. Assoc. Equine Pract. 1991;36:85–89.
  27. Waelchli RO, Winder NC. Distribution of histological lesions in the equine endometrium.. Vet Rec 1989 Mar 18;124(11):271-3.
    pubmed: 2711593doi: 10.1136/vr.124.11.271google scholar: lookup
  28. Walter I, Handler J, Reifinger M, Aurich C. Association of endometriosis in horses with differentiation of periglandular myofibroblasts and changes of extracellular matrix proteins.. Reproduction 2001 Apr;121(4):581-6.
    pubmed: 11277878

Citations

This article has been cited 13 times.
  1. Alpoim-Moreira J, Fernandes C, Rebordão MR, Costa AL, Bliebernicht M, Nunes T, Szóstek-Mioduchowska A, Skarzynski DJ, Ferreira-Dias G. Collagen Type III as a Possible Blood Biomarker of Fibrosis in Equine Endometrium. Animals (Basel) 2022 Jul 21;12(14).
    doi: 10.3390/ani12141854pubmed: 35883401google scholar: lookup
  2. Katila T, Ferreira-Dias G. Evolution of the Concepts of Endometrosis, Post Breeding Endometritis, and Susceptibility of Mares. Animals (Basel) 2022 Mar 19;12(6).
    doi: 10.3390/ani12060779pubmed: 35327176google scholar: lookup
  3. Westendorf J, Wobeser B, Epp T. IIB or not IIB, part 1: retrospective evaluation of Kenney-Doig categorization of equine endometrial biopsies at a veterinary diagnostic laboratory and comparison with published reports. J Vet Diagn Invest 2022 Mar;34(2):206-214.
    doi: 10.1177/10406387211062207pubmed: 34841986google scholar: lookup
  4. Kendziorski JA, Belcher SM. Strain-specific induction of endometrial periglandular fibrosis in mice exposed during adulthood to the endocrine disrupting chemical bisphenol A. Reprod Toxicol 2015 Dec;58:119-30.
    doi: 10.1016/j.reprotox.2015.08.001pubmed: 26307436google scholar: lookup
  5. Sadowska A, Molcan T, Słyszewska M, Skarzynski DJ, Ferreira-Dias G, Szóstek-Mioduchowska A. Transcriptomic Insights into Tumor Necrosis Factor α's Role in the Fibrosis-Related Processes of Equine Endometrial Fibroblasts. Int J Mol Sci 2025 Nov 24;26(23).
    doi: 10.3390/ijms262311344pubmed: 41373504google scholar: lookup
  6. Méndez-Pérez L, Wong YS, Ibáñez BO, Martinez-Hormaza I, Rodríguez-Álvarez L, Castro FO. Bidirectional Interaction Between PGE(2)-Preconditioned Mesenchymal Stem Cells and Myofibroblasts Mediates Anti-Fibrotic Effects: A Proteomic Investigation into Equine Endometrial Fibrosis Reversal. Proteomes 2025 Sep 8;13(3).
    doi: 10.3390/proteomes13030041pubmed: 40981201google scholar: lookup
  7. Matsuno Y, Imakawa K. Biological Aging and Uterine Fibrosis in Cattle: Reproductive Trade-Offs from Enhanced Productivity. Cells 2025 Jun 22;14(13).
    doi: 10.3390/cells14130955pubmed: 40643476google scholar: lookup
  8. Drzewiecka EM, Molcan T, Sadowska A, Piotrowska-Tomala K, Słyszewska M, Dias GF, Skarżyński DJ, Szóstek-Mioduchowska A. The myometrial transcriptome changes in mares with endometrosis. Sci Rep 2025 Jan 25;15(1):3173.
    doi: 10.1038/s41598-025-86742-0pubmed: 39863666google scholar: lookup
  9. Piotrowska-Tomala KK, Szóstek-Mioduchowska AZ, Drzewiecka EM, Jonczyk AW, Wójtowicz A, Wrobel MH, Ferreira-Dias G, Skarzynski DJ. Prostaglandin pathways in equine myometrium regulations: endometrosis progression. Front Vet Sci 2024;11:1479508.
    doi: 10.3389/fvets.2024.1479508pubmed: 39735588google scholar: lookup
  10. Piotrowska-Tomala KK, Szóstek-Mioduchowska A, Jonczyk AW, Drzewiecka EM, Wrobel MH, Hojo T, Ferreira-Dias G, Skarzynski DJ. The effect of lysophosphatidic acid on myometrial contractility and the mRNA transcription of its receptors in the myometrium at different stages of endometrosis in mares. BMC Vet Res 2024 Dec 19;20(1):571.
    doi: 10.1186/s12917-024-04384-2pubmed: 39696406google scholar: lookup
  11. Wang Z, Zeng S, Wang Y, Wang T, Qu H, Zhu Y, Li J. Reproductive Disorders in Donkeys: Current Evidence and Update. Animals (Basel) 2024 Aug 28;14(17).
    doi: 10.3390/ani14172494pubmed: 39272279google scholar: lookup
  12. Zdrojkowski Ł, Pawliński B, Skierbiszewska K, Jasiński T, Domino M. Assessment of Connective Tissue in the Equine Uterus and Cervix: Review of Clinical Impact and Staining Options. Animals (Basel) 2024 Jan 3;14(1).
    doi: 10.3390/ani14010156pubmed: 38200887google scholar: lookup
  13. Szóstek-Mioduchowska A, Wójtowicz A, Sadowska A, Moza Jalali B, Słyszewska M, Łukasik K, Gurgul A, Szmatoła T, Bugno-Poniewierska M, Ferreira-Dias G, Skarzynski DJ. Transcriptomic profiling of mare endometrium at different stages of endometrosis. Sci Rep 2023 Sep 27;13(1):16263.
    doi: 10.1038/s41598-023-43359-5pubmed: 37758834google scholar: lookup
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