Age affects dopamine receptor changes during chronic administration of fluphenazine

The effects of age on the alteration of brain dopaminergic receptors (spiperone binding) during chronic administration of fluphenazine was studied in young (7-month) and old (25-month) rats. Compared to age-matched saline controls, the old fluphenazine rats showed an earlier on-set and quantitatively greater decrease in specific binding of spiperone and increase in the KD of spiperone binding than young rats. Young rats showed an increase in the Bmax of spiperone binding at 6-weeks which was not shown by old rats.