The in Vivo and in Vitro Biosynthesis of Lung Tissue Glycopeptides

The biosynthesis of lung tissue glycopeptides in normal and vitamin A-deficient conditions was studied. Parallel to the change in the differentiative pattern in vitamin A deficiency there was a drastic decrease in the incorporation of glucosamine tagged with carbon 14 (14C) into a fucosecontaining glycopeptide. An anaplastic benzo[a]pyrene-induced tumor of the lung, transplanted in hamsters treated with excess retinoic acid, showed an increased glucosamine 14C incorporation into glycoproteins when incubated in vitro. Normal lung tissue was not affected by excess retinoic acid in its glycoprotein biosynthetic capacity.