Alteration of acetylcholine metabolism in the brain of zucker fatty rat.

The cerebral metabolism of acetylcholine (ACh) and [(3)H]quinuclidinyl benzilate([(3)H]QNB) binding to particulate fraction from the brain were examined using Zucker fatty rat. In all regions of the brain of fatty rat, ACh content showed a lower level than that of lean rat. Choline acetyltransferase activities in the striatum and medulla oblongata of fatty rat were significantly higher than those in lean rat, whereas the activities of acetylcholinesterase in the same brain regions of fatty rat were found to be significantly lower than those in lean rat. The [(3)H]QNB binding to particulate fraction obtained from the striatum of fatty rat was also found to be lower than that in lean rat. These results strongly suggest that the brain of Zucker fatty rat has impairments in the functions of cerebral cholinergic system.