Testicular aging involves mitochondrial dysfunction as well as an increase in UCP2 levels and proton leak

To address the possibility that mitochondria are involved in the age‐related loss of testicular function, we characterized mitochondrial bioenergetics in rat testis. A peak of mitochondrial functionality was detected in adult animals, with a decrease in both young and older animals. In the latter group a decrease in mitochondrial function was matched with an increase in proton leak and expression and activity of uncoupling protein 2 (UCP2), suggesting that proton leak may be involved in managing age‐dependent mitochondrial dysfunction.