[Phospholipid turnover in the liver mitochondria of rats on a diet with a varying fat and protein ratio].

Using the method of pulse introduction of labeled precursors the authors studied metabolism of rat liver mitochondrial phospholipids. The animals received high-protein diets (36% protein) containing 20% (diet II) and 36% (diet III) of fat as compared with the control (I) diet (18% protein and 20% fat). It appeared that the increase of protein in the diet (diet II) led to a reduction in the efficacy of 14C-palmitic acid incorporation into mitochondrial phospholipids, to a fall in the rate of metabolism of mitochondrial phospholipids and to a rise of their half-life within mitochondrial membranes, with the half-life of phospholipids labeled with 14C-palmitic acid in the fatty acid part being increased to a far greater degree as compared with that of phospholipids labeled with 3H-glycerin in the polar part of the molecules. However, in the presence of a high protein quota in the diet the fat/protein ratio agreed with the control level (diet III), whereas the metabolism of mitochondrial phospholipids remained close to the control values.