Glutamate dehydrogenase and its isozyme activity in olivopontocerebellar atrophy

Evaluation of glutamate dehydrogenase (GDH) in 12 patients with olivopontocerebellar atrophy showed deficiency of the enzyme in the group as well as in each patient. The activity of total GDH was 77.7% of that in controls. We also demonstrated two components of this enzyme differentiated by their thermostabilities. The activity of the heat-labile component was remarkably reduced in patients although that of the heat-stable component showed the same magnitude as in controls. These data suggest that GDH deficiency is mainly caused by its heat-labile component deficiency, which might be related to the pathogenesis of this disease.