Changes of [3H]spiroperidol binding in the renal artery of aged rabbits.

Using mature (12 months), old (70 months) rabbits and 3H-labeled spiroperidol, the characteristics of renal artery dopamine receptors were studied. In old age the dissociation constant of [3H]spiroperidol was unchanged, while maximum specific binding was reduced more than 45%. The present data seem to indicate an impairment of peripheral dopaminergic function in ageing.