EFFECT OF ADMINISTRATION OF AMINO ACIDS, ESPECIALLY OF L-DOPA AND ALPHA-METHYLDOPA, ON COMPOSITION OF CEREBROSPINAL FLUID IN EXTRAPYRAMIDAL SYNDROMES .I. ALTERATIONS OF CEREBROSPINAL FLUID IN PATIENTS WITH PARKINSONS DISEASE AND NORMALS

It was tested whether the administration of L-Dopa used in the treatment of Parkinson's syndrome will abolish alterations in the composition of cerebrospinal fluid known to occur in Parkinson's syndrome. To this test 9 patients with Parkinson's disease received an intravenous dose of 100 mg L-Dopa each while five normal controls received 50 mg each. The administration of this compound caused the serum concentrations of glutamine, arginine and oxaloacetic acid to rise for 2 h in all persons tested; thereafter concentrations fell below the starting levels with normal levels being gradually restored about 6 h later. Cerebrospinal fluid values of glutamine, arginine and oxaloacetic acid showed a slight decrease after 3 h to return to normal values on the 4th day. Cerebrospinal α-ketoglutaric acid as well as the activity of GPT rose, that of GOT dropped; starting levels were reached on the 2nd to 3rd day. In patients with Parkinson's disease though not in the controls the administration of L-Dopa resulted in the restoration to normal of the pathologically elevated concentrations of serine and glycine of cerebrospinal fluid while concurrently the concentrations of either phenylalanine or tyrosine went up. This effect became inapparent on the 3rd day. In addition, cerebrospinal fluid lysine rose after the dose of L-Dopa. There was a close temporary correlation between the duration of the alterations detectable by the analytical biochemical approach and the effect of the agent on the clinical picture. The results of this investigation suggest that in addition to the error of metabolism of aromatic amino acids there might be another one involving the metabolism of serine, whose clarification will further our understanding of Parkinson's syndrome. © 1969 Springer-Verlag.