Lipoprotein uptake by vascular smooth muscle cells of the rat cultured in 5% or 20% oxygen.

Freshly dispersed aortic smooth muscle cells of the rat were grown in either 5% or 20% oxygen. Cells proliferated more rapidly in 5% than in 20% oxygen although at confluency the protein content per cell was 20% less in the 5% than in the 20% oxygen environment. By electron microscopy, cell morphology was the same in both environments. Uptake of low-density and high-density homologous lipoprotein was unaffected by oxygen tension. Other studies, however, showed that induction of receptors for lipoprotein binding behaved variably in the low compared to the high oxygen condition. These differences were not associated with differences in lipid synthesis in the two conditions.