Distribution Pattern of Connective Tissue Fibers in Placentomes of Buffalo (Bubalus bubalis)

Abstract

Ongoing pregnancy in ruminants requires a strong structural connective tissue framework and production of extracellular matrix that provides mechanical stability and compensates the higher demand for uterine tensile strength during gestation. It has been postulated that failure of collagen breakdown seems to be related to retention of fetal membranes, hence the present study was undertaken to elucidate the distribution patterns of connective tissue fibers in placentomes of buffalo throughout the gestation. On the maternal side at 3 cm CVRL (42 days) sub-epithelial collagen and reticular fibers were observed in the developing primary crypts. From 17 cm CVRL (105 days) onwards the collagen content of the septa started decreasing and were present only at the tip while the reticular fibers showed more compact arrangement throughout the septal length. On the fetal side sparse arrangement of collagen and reticular fibers were observed in the chorionic plate, primary and secondary villi at 13 cm CVRL (87 days) with more compact arrangement afterwards. At late pregnancy there was extensive ramification of villi with fine terminal branches and more compact arrangement of connective tissue fibers. The results suggested that in the maternal caruncles the collagen content decreased and reticular content increased with pregnancy while in the fetal cotyledons both the collagen and reticular fiber contents increased and showed more compact arrangement that provided mechanical stability throughout gestation.