Huntington disease and Tourette syndrome. II. Uptake of glutamic acid and other amino acids by fibroblasts.
Injection of kainic acid, a rigid analog of the excitatory neurotransmitter glutamic acid (glu), into the neostriatum of rats produces a condition that mimics Huntington disease (HD) in at least 12 different morphological and biochemical parameters. These results suggested that one of the possible basic mechanisms in HD is a defect in the presynaptic of glial uptake of glu, resulting in chronic hyperstimulation and death of a specific set of neurons. To test this hypothesis, the uptake of glu was studied in 12 carefully matched sets of control-HD pairs and two lines of Tourette syndrome fibroblasts. Although the first six sets suggested a glutamate transport defect in HD cells, examination of 12 sets indicated that there were no significant differences between control and HD cells. The fibroblasts showed both a high and low affinity uptake of glutamic acid. Sodium dependent uptake of L-glutamate (L-glu) minus D-glutamate (D-glu) at 100, 1,000, and 10,000 Micrometers glutamate was normal in HD and Tourette syndrome cells.
D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000378:metabolism*; D001693:Biological Transport, Active; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D006801:Humans; D006816:Huntington Disease / Q000378:metabolism*; D007700:Kinetics; D012867:Skin; D012964:Sodium / Q000378:metabolism; D013237:Stereoisomerism; D005879:Tourette Syndrome / Q000378:metabolism*
D000596:Amino Acids; D005971:Glutamates; D012964:Sodium