Morpho-functional studies regarding the pathogenesis of the equine endometrosis with special emphasis on uterine secretions - preliminary results

The aim of the study was to investigate potential etiologic factors (e.g. endometritis) for the equine endometrosis as well as to determine possible effects by seasonal, cyclical and pregnancy-associated influences. Additionally, immunohistochemical methods were established to characterize the glandular secretion pattern of mares suffering from endometrosis compared to healthy control mares. For the histomorphological and immunohistochemical examinations 952 endometrial biopsies from 620 mares were used. The endometrosis can be divided in a destructive and a non destructive form, which can be either active or inactive. However, concerning quality and quantity there were no seasonal, cyclical or pregnancy-associated influences detectable. While the uterine secretion pattern of uteroglobin, calbindin, uteroferrin, uterocalin and glycogen follows a typical cycle-dependent staining intensity in the intact endometrium, the glandular epithelia within the fibrotic foci failed to. The latter revealed a distinct variety concerning the distribution and the staining intensity. These results indicate that subsequent disturbances of the uterine micro-environment are important factors leading to reduced fertility in mares suffering from endometrosis.