Decrease of Choline Acetyltransferase Activity of Rat Cortex Capillaries with Aging

Abstract

Choline acetyltransferase (ChAT) activity was estimated in brain cortex capillaries isolated from 3-, 12-, 18-, and 24-month-old rats. Maximum enzymatic activity was found at 12 months (55 +/- 0.3 pmol X mg-1 protein X min-1; mean +/- SEM) and then it decreased to reach a minimum at 24 months (34 +/- 3.1 pmol X mg-1 protein X min-1). A less marked decrease of enzymatic activity was also found in cortex homogenate and in a synaptosomal fraction obtained from the same groups of rats. Loss of ChAT of brain capillaries with aging could be related to a general phenomenon of cortical cholinergic deficit in that condition.

Choline Acetyltransferase Activity in the Rat Brain Cortex Homogenate, Synaptosomes, and Capillaries After Lesioning the Nucleus Basalis Magnocellularis

“…ChAT activity has been found also in microvessels and capillaries isolated from the rat (Goldstein et al, 1975;Santos-Benito and GonzAlez, 1985) and bovine (Estrada et al, 1983) cerebral cortex. The latter authors suggest that capillary ChAT activity may be located in nerve terminals which end in the basement membrane of cerebral capillaries.…”