Factors affecting protein and glycoprotein synthesis by rat kidney mitochondria in vitro

Incorporation of 14C-labeled leucine and mannose were used as indices of protein and glycoprotein synthesis by isolated rat kidney mitochondria. Uninephrectomy, certain salts including NaCl and heavy metals, detergents such as digitonin and lysophosphatidylcholine, and various antibiotics were studied for their effect in this in vitro assay system. Amino acid incorporation by mitochondria into macromolecules was adversely affected by a number of the conditions studied while carbohydrate incorporation was less frequently influenced. The number of variables capable of influencing the assays system indicate that caution must be used in the interpretation of in vitro enzyme reactions especially in the study of experimental nephropathies. Alterations in mitochondrial macromolecular synthesis may be a feature of various types of renal injury though the importance of mitochondrial biosynthetic activity to the overall cell response remains to be established.