Effects of L-glutamate on viabilities of cultured diploid skin fibroblasts and lymphocytes. Increased toxicity not observed in Huntington's disease.

The toxicity of L-glutamic acid toward cultured fibroblasts and lymphocytes from age-matched, sex-matched controls, patients with Huntington's disease (HD) and patients with other diseases has been studied. In an initial non-blinded study, L-glutamic acid (15 mM) exerted a significant toxic effect on HD fibroblasts, decreasing viability by approximately 60% after 48 h exposure. The magnitude of the toxic effect on HD fibroblasts as a group was significantly different from the mean effect on the normal control group (P less than 0.003) and non-HD control group (P less than 0.004). However, there was variability in the sensitivity of a given fibroblast culture to L-glutamate. This toxic effect was also seen in several normal control and non-HD control fibroblasts. In a second blinded study using cultured fibroblasts from HD patients and age-matched, sex-matched controls, we were unable to distinguish between HD and control cultures. No difference in L-glutamate toxicity was observed between control and HD lymphocytes in short-term cultures. We conclude that the toxicity of L-glutamate is not specific for HD cells and that this experimental approach will be of little value in identifying cells from patients with HD.