Ultrastructure of Aging Human Umbilical Artery and Vein

Abstract

Qualitative and quantitative changes in the human umbilical artery and vein were observed in 15 human specimens at different stages of development. Features such as intimal thickening and cellular lipid accumulation were found in umbilical vasculature. Cellular origin and quantification of lipid-containing cells were determined by electron microscopy. Within 1 month after birth, lipid-containing cells originating from macrophages were observed in the umbilical artery, while those originating from smooth muscle cells were observed in both the umbilical artery and vein. Lipid droplet formation appeared to be independent and different in macrophages and smooth muscle cells; the former cells were stimulated to produce lipid droplets primarily by plasma insudation and the latter cells primarily by hypoxia. These findings indicate that ultrastructural changes observed in closing umbilical vasculature may closely parallel and serve as a model for atherosclerotic changes which occur in mature vessels.

Ultrastructure of Human Umbilical Artery and Vein

“…It was reported that sparse collagen fibers were found, but almost no elastic fibers in the media layer was observed (9). Our study also confirmed this.…”

“…An important feature of the umbilical arteries media layer at this time was the increase in rough endoplasmic reticulum content. However, in a previous study a decrease in the amount of rough endoplasmic reticulum and glycogen was reported in the arterial media layer at twenty-five week (9). The important finding of our research was the increase in rough endoplasmic reticulum content and the amount of glycogen in the venous media layer at twenty-five week.…”

“…The mitochondria structures had become quite enlarged and Weibel-Palade bodies were observed. Takagi et al (9) have shown that cells contained some bodies like lysosome, large amounts of rough endoplasmic reticulum and a few glycogen granules in the venous endothelium at the eighteen week stage. In this study, Weibel-Palade bodies were found in the periphery of cells.…”

“…Golgi apparatus was well-developed and Weibel-Palade bodies were quite numerous in venous endothelium (4,8). The basal membrane of vein was better defined than that of the arteries (7,9). Generally, in the studies that have been done, the development of the endothelial cells of the umbilical vessels was observed, but the media layer was not considered.…”

Relevance of Hypercholesterolemia to Fetal and Pediatric Atherosclerosis

“…Dire consequences also follow spontaneous rupture of a venous varix. Postnatally, umbilical arteries were found to contain lipid in SMCs W. E. Stehbens and macrophages, although anorexia and reduced £ow could contribute to these changes [58,59]. Impaired umbilical artery £ow whether from degeneration, trauma, or increased placental vascular resistance may contribute to retarded fetal development.…”