Delayed loss of striatal dopamine receptors during aging of dietarily restricted rats.

Dietary restriction by feeding every other day retards the normal age-associated loss of dopamine receptors from the corpus striatum of the rat. Ad libitum fed animals lose about 40% of the receptors labeled by [3H]spiperone between 3 and 24 months, while the loss is only about 20% over the same period in restricted rats. Ultimately, by 30 months of age, values for restricted animals drop to those of 24-month-old ad libitum-fed rats. The mean lifespan of restricted rats, however, is about 40% longer than the 22-24 months characteristic of ad libitum-fed counterparts. The effect of restriction appears to be chronic rather than acute since ad libitum-fed rats which are restricted for 2 weeks prior to sacrifice possess receptor levels comparable to 24-month-old rats maintained on ad libitum feeding for their entire lifetime.