[Transport of steroid hormones by serum lipoproteins]

Binding and distribution of glucocorticoids as well as of some of their precursors in lipoprotein fractions of human and rat blood serum were studied. Binding of the corticosteroids with blood serum lipoproteins was shown by ultracentrifugation and gel filtration. The binding of corticosteroids with lipoproteins was accompanied by alterations in the apoprotein conformation, detected by means of quenching of tryptophane fluorescence. The data obtained suggest that the lipoproteins are involved in transport of corticosteroids.