Lack of age-dependent changes in rat heart mitochondria

The effects of aging on the composition and function of cardiac mitochondria from rats exhibiting significant decreases in synaptic brain mitochondria composition and function have been studied. Cytochrome content and cytochrome absorbance wavelength maxima do not change in heart mitochondria. Respiratory activities, respiratory control ratios, ADP/O ratios, and H+/O ratios do not change with increasing age. Unlike in brain synaptic tissue, energy output of the heart does not decrease with age.