Maintenance on L-deprenyl prolongs life in aged male rats.

The effect of l-deprenyl on longevity was examined in male Fischer rats. Subcutaneous injections of either l-deprenyl (0.25 mg/kg) or saline were given every other day starting at 23 to 25 months of age. The deprenyl-treated animals showed a significant increase in both mean and maximum survival. The differences were largest in the longest surviving animals, suggesting that an earlier onset for treatment may be beneficial. Analysis of body weights ruled out deprenyl-induced dietary restriction as an explanation for the group differences in survival. To the contrary, after about four months of treatment, the animals of l-deprenyl showed a slower rate of decrease in body weight than the controls.