Porcine Uterine and Placental Extracellular Matrix Molecules Throughout Pregnancy

the molecules that constitute the extracellular matrix are important in several functions related to tissue support and cell-cell, cell-extracellular matrix interaction. among the macromolecules that constitute the mentioned matrix we find osteopontin, fibrinogen and collagen. the present study was undertaken to analyze the rol of osteopontin, fibrinogen and collagen in uterine-placental interface during normal porcine gestation. uterine and placental tissues from crossbred gilts of 30 (n=5), 60 (n=5), 70 (n=5) and 114 (at term, n=5) days of gestation were used. macroscopic analysis of the embryos/fetuses allowed us to determine their gestational age by means of the crown-rump lenght. haematoxylin-eosin and masson's trichrome dyes along with light microscopy were used to structure analysis of every selected period of gestation. a spacial and temporal study of osteopontin and fibrinogen was performed through immunohistochemical technique. determination of collagen fibers was carried out through picrosirius red technique and polarizing microscopy. results were expressed as semi-quantitative. higher expression of osteopontin was observed at early periods of gestation, mainly in uterine and placental villi, endometrial gland epithelium and histotroph. fibrinogen expressed abundantly in fetal mesenchyme in every period analyzed and in fetal and maternal vessels at day 70. negative expression of collagen fibers was observed in villi, however increasing expression of thick fibers throughout pregnancy was detected in uterine stroma and myometrium. these results confirm the importance of osteopontin, fibrinogen and collagen in the support of uterine and placental structures and in the suitable maintenance of pregnancy.