A decrease in neural sialyltransferase activity in Alzheimer's disease.

The activities of both a particulate and soluble form of the sialyltransferase enzyme have been examined in post-mortem brain samples from Alzheimer's disease patients and age-matched controls. There was a considerable decrease in the activity of both the soluble and membrane-bound forms of the enzyme in the frontal and temporal cortical lobes, although no change was observed in the hippocampus. There was, however, no change in activity of the Golgi marker enzyme thiamine pyrophosphatase. Therefore, it is suggested that the decrease in sialyltransferase enzyme activity may be a specific biochemical event associated with the AD-like neurodegeneration.