[Brain aminoacids in phenothiazin-induced Parkinsonism. Drug-induced parkinsonism in the rat--a model for biochemical studies of the Parkinson-syndrome]

[Biosynthesis of amino acids from glucose in the central nervous system in the Parkinson syndrome]

The incorporation of labelled carbon from glucose U-14C into CSF amino acids was investigated in three patients with Parkinson's disease and in three control persons with comparable age and physical stature. Comparing the specific radioactivities of serum and CSF one can postulate that the labelled amino acids found in the CSF are synthesized mainly by brain tissue. The resorption of glucose into the CNS and therefore the synthesis of amino acids from glucose was more rapid in controls; labelled alanine and glutamine appeared later in the CSF of the patients. As expected, in the controls the specific radioactivity of glutamic acid was found to be higher than that of glutamine, in patients the labelling of glutamine was higher as was that of serine, glycine, aspartic acid and asparagine. From our knowledge concerning the compartmentation of the metabolism of glutamate, we assume that in Parkinsonism the metabolic activity of neurons is reduced but that of astroglia is enhanced.

Incorporation of [U-14 C]glucose into metabolites of brain, liver and blood of rats pretreated with reserpine or phenothiazines

Parkinsonism was induced in rats by using phenothiazines (Butyrylperazin and Thioproperazin). (P-group), or reserpine, (R-group). [U-14 C)D-glucose was administered when the symptoms of Parkinsonism had become fully developed. Concentrations and radioactivities of different metabolites were studied in brain, liver and blood serum. 1. Both types of treatments resulted in a decrease in the synthesis of amino acids from [14C]glucose in the brain. The concentrations of amino acids and the glycogen remained uneffected. Phenothiazines enhanced the conversion of lipids, while reserpine increased their concentration. 2. Reduced de novo synthesis of amino acids was recorded in the liver. Phenothiazines resulted in the storage of glycogen and lipids; reserpine resulted in the storage of lipids and enhanced the conversion of glycogen. 3. Both treatments caused a fall in the amino acid concentration of the blood serum. A rise in the specific radioactivity of blood amino acids was observed in the P-group, while a decrease in specific radioactivity was observed in the R-group. A hyperglycemia was induced in the R-group with reduced specific radioactivity of glucose in both P-and R-groups. A reduction in lipid concentration of blood serum was achieved with an increased specific radioactivity in P-group and decreased radioactivity in R-group. 4. The changes in amino acids common to both treatments are also observed in human Parkinsonism.

A double-blind trial of baclofen against placebo in the treatment of schizophrenia

Twenty male chronic schizophrenic patients participated in a double-blond between-patient study of the GABA-like drug baclofen to evaluate the antipsychotic effect of baclofen. No difference was found between the 10 patients who received baclofen and 10 who received placebo with regard to the number of days before a worsening of their psychiatric condition necessitated treatment with chlorpromazine, the total score for psychotic symptoms before and after treatment for 10 weeks, or the total consumption of chlorpromazine. Discontinuation of baclofen did not exacerbate the psychotic symptoms. Baclofen was superior to placebo in the treatment of anxiety, which is of particular interest in view of the recent theories on the mechanism of action of benzodiazepines. The relationship between the gabergic system and the dopaminergic system with regard to the substantia nigra and the corpus striatum is discussed as well as the suggestion based on animal experiments that baclofen has an antipsychotic effect.

Drug-induced parkinsonism in the rat- a model for biochemical investigation of the parkinson-syndrome. III. The incorporation of D-glucose-14C(U) in amino acids of brain and liver from rats pretreated with reserpine or with phenothiazines

Following treatment with reserpine or alternatively with a combination of phenothiazines (Randolektil, Majeptil) a drug-induced parkinsonoid reaction was provoked in rats. Twenty min before decapitation, 18 muCi d-glucose-14C(U) was administered intravenously. Concentration and radioactivities of glutamic acid (glu), glutamine (gln), serine (ser), and glycine (gly) were assayed in some regions of brain and in liver. Separation was performed by a combination of paper electrophoresis and chromatography or by an automatic amino acid analyzer. 1 After reserpine, the concentrations of serine and glycine were increased ten-fold while their specific activities decreased by the same factor. The interconversion serine-glycine was not affected. The concentration of glutamic acid was reduced while its specific activity remained constant. 2. After phenothiazines, the concentrations of serine and glycine in brain were also increased but their specific activities were decreased to a different degree. This indicates an additional effect on the serine-synthesis from glucose. The interconversion serine-glycine was also altered. The concentration of glutamic acid was decreased but specific activity was constant except in the thalamus region tested. 3. The influence of both treatments on amino acid turnover in liver differed from the observed impairment of brain metabolism. 4. Possible correlations between the changes in amino acid metabolism, catecholamines, and the neurologic parkinsonian symptoms are discussed.

Glycine levels in the degenerated human spinal cord

Tissues from non-degenerated tissue of 18 patients were assayed for glycine concentration in grey and white matter in the thoracic, cervical and lumbar regions. Confirming earlier results, glycine concentration was found to be maximal in the grey matter of the lumbar segments of the lateral column. Analysis of tissue from 11 human spinal cords showing unilateral Wallerian degeneration, 4 cords with amyotrophic sclerosis and 4 cords with bilateral Wallerian degeneration failed to show statistically significant differences when compared with control values. The results argue against a supraspinal origin of glycine and suggest that glycine levels are regulated locally or at a segmental level in the spinal cord in man.