Acetylcholinesterase and butyrylcholinesterase in frontal cortex and cerebrospinal fluid of demented and non-demented patients with Parkinson's disease.

The molecular forms of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were studied in frontal cortex (grey and white matter), postmortem, and in cerebrospinal fluid (CSF) of demented patients with Parkinson's disease compared to controls and non-demented parkinsonians. In the frontal cortex, AChE activity decreased significantly in both demented and non-demented parkinsonian subjects compared to controls; the 10S form of the enzyme was significantly lower in demented parkinsonians than in the non-demented subjects. The decrease in AChE activity was correlated with a decrease in choline acetyltransferase activity thought to reflect lesion of cholinergic neurones in the substantia innominata which innervate the cerebral cortex. BChE activity decreased only in the non-demented parkinsonians; in the demented subjects, BChE activity was at control levels. Similar results were obtained with grey and white matter, although absolute levels of the two enzymes were different in the two types of tissue, suggesting that the enzymes were affected in the cholinergic neurones before transport to cortical nerve terminals. No decreases in AChE or BChE activity were observed in the CSF of the patients studied. On the contrary, AChE and BChE levels were significantly higher in demented parkinsonian patients compared to the non-demented subjects.