Cultured fibroblasts in Huntington's disease. I. Effects of L-glutamic acid.

Huntington's disease (HD) is associated with a defect in the CNS that may involve the "glutamine cycle." There is conflicting evidence that other cell types also manifest the abnormality. Thirty HD, 20 "at-risk," and 20 normal cell lines were used in studies of viability, plating efficiency, cell growth "glutamine rescue," and tritiated thymidine and tritiated leucine incorporation in the presence of O to 30mM L-glutamic acid. Cell viability, plating efficiency, and growth were decreased, with increasing glutamic acid concentrations. Tritiated thymidine and tritiated leucine incorporation was slightly affected by glutamic acid. Glutamine rescue was significantly more effective in normal cells than in HD cells. Fibroblasts in HD are a little more sensitive to L-glutamic acid than normal cells.