Morphological evidence of endogenous lipid production in swine ductus vasculature

Specimens of ductus arteriosus and venosus from 2-month-old and 6-month-old swine were examined by electron microscope. The purpose of the study was to observe the effects of vessel closure and hypoxia on medial vascular smooth muscle cells. At 6 months of age, smooth muscle cells from the medial layer of ductus arteriosus showed signs of considerable cellular degeneration and contained lipid vacuoles which were often surrounded by granular endoplasmic reticulum. Specimens from the portal side of ductus venosus showed initial stages of smooth muscle cell degeneration and lipid vacuolization, while samples from the hepatic side of ductus venosus were nearly normal. This study contains the first reported morphological evidence of organelles in vascular smooth muscle cells which are responsible for endogenous lipid droplet production.