The binding of [3H]dolichol by plasma high density lipoproteins.

Radioactive dolichol was rapidly taken up by a plasma protein fraction following the intravenous injection of detergent suspended [3H]dolichol into rats. The half-life of labeled dolichol in the plasma was found to be approx. 13 h. Density gradient centrifugation or gel filtration of samples of human or rat plasma incubated with [3H]dolichol suspensions also showed that the labeled material became associated with the same plasma protein fractions as in the in vivo studies. Evidence was obtained to indicate that dolichol is specifically associated with the high density lipoprotein fraction of plasma. The possible role of high density lipoproteins as a vehicle for dolichol transport and the problems involved in the binding of this long moleculare are discussed.