Role of matrix metalloproteases 2, 9 (MMP-2, -9), orphanin FQ and others peptides in vascular tone of human umbilical cord at term

Umbilical cord is the structure that connects the fetus to the placenta. Umbilical cord at term is made of three vessels surrounded by the Wharton’s jelly, a mucous connective tissue rich in glycosaminoglycans, proteoglycans and different types of collagens and other microfibrils, which are responsible for its elasticity and its mechanical properties.Umbilical cord seems to lack any capillaries or lymphatics and umbilical vessels are unique in lacking any innervation; thus endothelial cells may play the major role in the local control of the blood flow. Objectives. In this paper we investigated in human umbilical cord at term the expression of some peptides involved in the regulation of the vascular tone, and the expression of some enzymes responsible for the remodelling of the extracellular matrix. Materials and methods. Through immunohistochemistry we investigated the expression of Matrix metallopeptidase 2 and 9 (MMP-2, MMP-9), Orphanin FQ (OFQ), Oxytocin (Ox), Atrial natriuretic factor (ANF), Endothelial nitric oxide synthase (eNOS) and Inducible nitric oxide synthase (iNOS) in human umbilical cord. Results. We identified the expression of all these proteins and their localization in the different territories of umbilical cord.