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© 1991 American Academy of Neurology Dihydropteridine reductase activityLack of association with serum aluminum levels and cognitive functioning in patients with end-stage renal diseaseDepartments of Neurology (Dr. Bolla and L. Wieler) and Nephrology (Dr. Briefel), Francis Scott Key Medical Center, and the Department of Psychiatry and Behavioral Sciences (Dr. Bolla), the Johns Hopkins University School of Medicine, Baltimore, MD; and the Laboratory of Neurochemistry (Drs. Milstien and Kaufman), the National Institute of Mental Health, Bethesda, MD. Although increased levels of aluminum (Al) are present in patients with dialysis encephalopathy (DE), it is unclear if the association is causal. The enzyme dihydropteridine reductase (DHPR) plays a critical role in neurotransmitter formation and its activity. Elevated levels of Al are reported to decrease DHPR activity, which would alter neurotransmitter metabolism, thus producing DE. We examined the association between erythrocyte DHPR activity and Al levels, attention/psychomotor skills, and depression in a group of 21 patients with end-stage renal disease. DHPR activity was not related to Al level, mental status, psychomotor ability, or depression score. After administration of deferoxamine (an Al chelating agent), Al level increased significantly but DHPR activity remained the same. Our results suggest that the mechanism for the development for DE does not involve alterations of neurotransmitter metabolism caused by Al-mediated reductions in DHPR activity. Address correspondence and reprint requests to Dr. Karen I. Bolla, Johns Hopkins University School of Medicine, Department of Neurology, Francis Scott Key Medical Center, 4940 Eastern Avenue, Baltimore, MD 21224. Supported by a grant from the National Institutes of Environmental Health 1R29ES04427. Received March 12, 1991. Accepted for publication in final form May 7, 1991.
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