The effect of diabetes on renal lysine utilization

Current evidence indicates that a hydroxylysine-rich glycoprotein may be of importance in the structural organization and accumulation of glomerular basement membrane in the diabetic state. To further evaluate the role of insulin deficiency in renal glycoprotein synthesis, the effect of experimental diabetes on the incorporation and hydroxylation of 14C-lysine by cell-free systems prepared from rat renal cortex was examined. Microsomal protein synthesis was increased in diabetic preparations, but the rise in renal cortical collagen synthesis relative to total protein synthesis was greater. These changes were not duplicated by the addition of a mixture of unlabeled amino acids or hydroxylation cofactors to incubations with preparations from normal animals.