Kish S J, Chang L J, Dixon L M, Robitaille Y, DiStefano L
Human Neurochemical Pathology Lab, Clarke Institute of Psychiatry, Toronto, Ontario, Canada.
Metab Brain Dis. 1994 Mar;9(1):97-103. doi: 10.1007/BF01996077.
We measured the levels of three glutamate metabolizing enzymes, namely, glutamate dehydrogenase (GDH), aspartate aminotransferase (AAT), and glutamine synthetase (GS) in cerebellar and occipital cortices of nine patients with dominantly-inherited olivopontocerebellar atrophy (OPCA; spinocerebellar ataxia type I). As compared with the controls, mean GDH activities in cerebellar cortex of the OPCA patients were normal whereas levels of AAT (-17%) and the glial enzyme GS (-27%) were significantly reduced. No statistically significant changes were observed in occipital cortex, a morphologically unaffected brain area. We suggest that the decreased GS levels could reflect impaired capacity of astrocytes to metabolize glutamate which might contribute to the degenerative processes in OPCA cerebellum.
