Pathomorphological changes and immunolocalization of matrix metalloproteinases in the placenta of cows during afterbirth retention

For the first time, using histochemical and immunohistochemical methods, epithelialized defects with signs of dystrophy in the crypts of caruncles in cows with afterbirth retention were established. The number of diplocaryocytes per unit area in the placenta of a cow during normal delivery was three times higher than the number of cells in cows with afterbirth retention. In the stroma of the villi of the allantochorion of the cotyledons, an increase in the number of collagen fibers and an increase in the number of fibroblasts, which are larger than in normal childbirth, have been established. In samples obtained from cows with afterbirth retention in the stroma of defragmented maternal crypts, the distribution of MMP was established, and immunopositive cells were fixed around the vessels, with active production of MMP-1 and MMP-3. Decreases in MMP-2 and MMP-9 in placentomas were observed in the allantochorion villi of the fetal part of the placenta. Thus, MMP-2 and МMP-9 are localized in the cotyledon and can affect the timely release of allantochorion villi from the crypts of the caruncles, ensuring the separation of fetal membranes from the maternal placenta in cattle.