Properties of density gradient-separated liver mitochondria from triiodothyronine-treated rats.

Abstract

SummaryTwo populations of liver mitochondria from T3-treated rats, which were separated on sucrose density gradients, and normal rat liver mitochondria were studied. The more dense mitochondrial band from T3-treated rats consistently had the highest in vivo rate of 32P-orthophosphate incorporation into phospholipids and was significantly different from 32P incorporation into the phospholipids of the less dense mitochondrial band at 60 min. No differences in the in vivo rate of 14C-l-leucine incorporation into mitochondrial protein or in the major mitochondrial fatty acids were found among the bands studied. Significant differences in phospholipid:protein ratios were found between the two mitochondrial bands of the T3-treated group. The density differences of the mitochondrial bands might be explained by alterations in the phospholipid:protein ratios since changes in these ratios correlate with mitochondrial densities.The authors thank Dr. Donald Greiff for the use of his ultracentrifuge, and Drs. Roberto ...