Pathogenesis of endometrial gestational angiosclerosis in mares - an electron microscopic investigation.

The gestational changes of the uterine vessels of various species have been described as „gestational sclerosis“ in the beginning of the last century (Pankow 1906, Ahlborn 1920). Further investigations of endometrial blood vessels of the mare began in the 1990 s (Schoon et al. 1994, Kriesten 1995, Gruninger et al. 1998, Schoon et al. 1999). During the 11 months of gestation of the mare, the endometrium accommodates analogously to the demands of highly increased vascular and glandular activity (Rossdale 1997). After foaling, the endometrium in general has a pre-gravid histological appearance by Day 14 post partum (Blanchard and Varner 1993, Steiger et al. 2002). The goal of this study was to describe the gestational changes of endometrial vessels of the mare and to specify the influence of pregnancy on the vessels. In order to obtain further information on the pathogenesis of endometrial angiosclerosis, the puerperal involution of the endometrial vessels was specifically considered.