Influence of age on the effects of chronic fluphenazine on receptor binding in rat brain

The effects of age on alterations in brain dopaminergic (spiperone), beta-adrenergic (DHA), alpha-adrenergic (WB-4101), and cholinergic (QNB) binding induced by chronic administration of fluphenazine was studied in the rat. Compared to age-matched saline controls, older-age (25 month) fluphenazine rats showed: (a) a similar percent increase in specific spiperone binding (at 0.1 nM) but a slightly smaller increase in the Bmax of spiperone binding in the striatum than younger fluphenazine-treated rats; (b) a substantially greater increase in the Bmax of DHA binding and a slightly greater increase in Bmax of WB-4101 binding in the cerebral cortex than younger fluphenazine-treated rats. There was no significant interaction of age with the effect of chronic fluphenazine on QNB binding in rat striatum.