Effect of aging on striatal dopamine receptor subtype recovery following N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline blockade and relation to motor function in Wistar rats.

Recovery of D1- and D2-dopamine receptors in Wistar rat corpora striata were assessed following N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ blockade). Absolute recovery declines during senescence approximately 25 and 40% for the D1- and D2-subtypes, respectively. Net biosynthetic reductions are comparable to the overall age-related decreases in receptor concentrations for this rat strain. EEDQ administration also induces catalepsy behavior and impairs ability of animals to remain on an inclined screen. Recovery of inclined screen performance is also reduced with age, but is not strictly proportional to recovery of receptor concentrations.