The effect of age on mitochondrial ultrastructure and enzymes.
The ultrastructure of perfused livers and of mitochondrial fractions from 6 months and 30 month-old C57/BL mice were studied. In old mice the liver cell mitochondria were enlarged and rounded with a light "foamy", vacuolated matrix, short cristae and a loss of dense granules. Quantitative studies showed a 60% increase in the mean size and an increased proportion of larger mitochondria in intact 30 month-old perfused livers. Endothelial and Kupffer cell mitochondria were smaller than those of the parenchymal cells. Mitochondria in pellets prepared from 6 and 30 month-old livers were rounded and condensed although there were a few larger and "foamy" mitochondria in the preparations from old mice. Up to 47% of large mitochondria in the old livers were lost during cell fractionation. The levels of cytochrome oxidase and malate dehydrogenase were slightly decreased with age but their cytochemical localization was unchanged.
D000375:Aging; D000818:Animals; D003576:Electron Transport Complex IV / Q000378:metabolism*; D007728:Kupffer Cells / Q000648:ultrastructure; D008099:Liver / Q000166:cytology; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000201:enzymology / Q000648:ultrastructure*
D008291:Malate Dehydrogenase; D003576:Electron Transport Complex IV