The expression and distribution of matrix metalloproteinases (MMP) 2 and 9 were evaluated in helth endometrium and in chronic endometrites of mares by means of immunohistochemistry method. Sixty endometrial biopsies were utilized. Expression of MMP-2 was observed in vascular wall, stromal cells, and glandular epithelium. More intense immune reaction was seen in glandular epithelial cells in category III endometritis and in vascular wall in category I endometrium. MMP-9 immune reaction was diffuse and was seen in luminal and glandular epithelium; vascular wall region; and stromal, endotelial, and inflammatory cells. There was a decreased of the immunohistochemical marking in vascular wall region as increased the degree of endometrial injury, as well as reducing the intensity of reaction in this compartment. There was no relation in immunohistochemistry expression of metalloproteinases with the type of endometritis
equine; endometrium; inflammation; fibrosis; metalloproteinases
