Uptake of dolichol by Vero cells.

Characterization and kinetics of dolichol uptake by a Vero cell line are reported. Vero cells incorporate dolichol in a time- and dose-dependent manner. Optimal uptake is found at 37 degrees C and at a pH of 7.4. In contrast to cholesterol, an inhibitory effect on the dolichol incorporation is found for farnesol, geraniol, and retinol. Long chain polyprenols were slightly stimulatory. The translocation seems not to be highly energy dependent. The lack of substantial inhibition by chloroquine does not plead for a receptor-mediated endocytosis. Incorporated dolichol was distributed over both membranes and supernatant fractions, paralleling the distribution of the lysosomal marker beta-N-acetylhexosaminidase. The incorporated dolichol is subject to a fast efflux process, which is potentiated by the presence of lipid acceptors in the extracellular medium.