Myofibroblasts In The Connective Tissue Of Human Umbilical Cord

ObjectUsing Immunohistochemistry (IHC) and transmission electron microscopy (TEM) to confirm the presence of myofibroblasts in the connective tissue of human umbilical cord.Methods:Tissue of umbilical cord was obtained from 14 cases of normal full term pregnancy. The expressions of actin, vimentin and desmin of spindle-shaped cells were immunohistochemistry studied and the fine structure of these cells was observed under transmission electron microscopy.ResultsPlenty of spindle-shaped cells were found in the fibroblast layer of umbilical cord. Immunohistochemically, most of these cells expressed actin, vimintin and desmin. Under the TEM, they displayed thefollowing characteristics of myofibroblast: 1. abundance of rough endoplasmic reticulum and mitochondria appearing in the both sides of the nucleus; 2. bundles of 5nm intracytoplasmic microfilaments with dense bodies, which were similar to those of smooth muscles cells; 3. irregular shaped nuclear with infoldings and glycogen accumulations; 4. cell to cell attachments with intercellular junctions, such as desmosomes, gap junctions. 5. incomplete basement membrane.ConclusionSince the myofibroblasts in human umbilical cord connective tissue have following biological functions: 1. to generate intracellular contractile force and to transmit this force to the surrounding tissue, which makes the umbilical cord as a whole body to contract, flex and elongate in order to adopt to baby's grow, motion, and increase of amnion fluid; 2. to synthetize collogen type III, which is the major elastic component of umbilical cord, we conclude that the myofibroblast may function as an elastic element of umbilical cord.