Age Differences in the Cortisone Induced Changes of the Mice Hepatic Cells

Part 3. Ultramicromeasuring Studies on Mitochondrial Cristae

Abstract

Age differences in the cortisone induced changes of mouse hepatic cell mitochondria were studied electronmicroscopically, using female mice of SM strain of different ages.
In the young and old mice, the mitochondria decreased in number and increased in size by cortisone treatment, more markedly in the old. In the middle aged, though the mitochondria were decreased in number, they did not significantly increase in their size.
Before treatment, mitochondrial cristae were arranged most compactly in the old aged. After treatment, mitochondrial cristae became more compact accompanied with the decrease in number of mitochondria. The increase of the length of the cristae and its recovery were most remarkable in the young aged. In the middle aged, mitochondrial cristae were sparcely arranged during the course of the experiment.
In the old aged mice, each mitochondrion with compactly arranged cristae seems to function more actively to compensate for the numerical loss of cells and their mitochondria.