Özet:
Aim: Our objective in this study was to investigate ultrastructure of endothelial and muscle cells of human umbilical vessels.
Material and Methods: Ten umbilical cords were used for this study. These cords represented periods of gestation from sixteen
weeks to full-term. The specimens were fixed in 5 % buffered glutaraldehyde for four hours at 4oC. The sections were postfixed for
two hours in a solution of 1% osmium tetroxide prepared with Millonig phosphate buffer. Sections were dehydrated in ethanol and
propylene oxide and then embedded in araldite. They were stained with uranyl acetate, examined electron microscopically.
Results: Rod- shaped bodies were observed in the arterial endothelium in the early stage as described by Weibel-Palade. Large
numbers of mitochondria and increased lipid and vacuoli structures and increased Weibel-Palade bodies were also noted in fullterm. the muscle cells of the umbilical vein were characterized by prominent crystalized structures of mitochondria at sixteen
weeks.These structures were degenerated at full-term, and myelin figures were observed.
Conclusion: The endothelial and muscle cells of the umbilical vessels from early stage to full-term showed morphological changes.