Hanada Michiko, Maeda Yousuke, Oikawa Masa-Aki
Faculty of Animal Health Technology, Department of Animal Health Technology, Yamazaki Gakuen University, Tokyo 150-0046, Japan.
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.
J Equine Sci. 2014;25(2):45-52. doi: 10.1294/jes.25.45. Epub 2014 Jun 25.
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.
对50匹经尸检的非妊娠日本纯种繁殖母马（年龄1 - 30岁）的子宫进行研究，以阐明日本纯种母马子宫内膜异位症的组织病理学特征以及子宫内膜异位症病变在整个子宫中的分布模式。在所有6岁以上的动物以及所有21匹12岁以上的母马中均观察到子宫内膜异位症。除子宫内膜异位症的病理形态学特征，如伴有子宫内膜萎缩的基质子宫内膜纤维化、腺周纤维化和子宫腺体减少外，受影响的母马还表现出子宫壁动脉、静脉和淋巴管的弹性纤维增生、子宫平滑肌层萎缩以及子宫肌层平滑肌束间胶原纤维增生。组织病理学变化的严重程度随年龄增长而增加。伴有弹性纤维增生的淋巴管显示明显的淋巴充血，导致淋巴水肿。随着年龄的增加，这些病变的分布范围倾向于从局部扩展到整个子宫的弥漫性累及。基于这些发现，我们推测衰老在子宫内膜异位症的发病机制中起作用；子宫血管生成或血管病变引起的循环障碍，特别是动脉血供减少和静脉引流障碍，导致淋巴引流减少（淋巴水肿），与子宫内膜纤维化的发生和进展密切相关，并且子宫肌层纤维增生可能导致植入期或产褥期子宫肌层功能减退。
