Age-dependent changes in the mechanisms regulating dopamine uptake in the central nervous system.

Na+-dependent binding of 3H-Cocaine is located on dopaminergic terminals and is related to the dopamine uptake system. Studies on senescent rats indicate a decrease in 3H-Cocaine binding density in the striatum. In the same tissue an increase in the Km for dopamine uptake is observed. These changes might be relevant in the age-dependent alterations in dopaminergic function.