Ultrastructural features of human galactosaemic fibroblasts: effects of different nutritional environments.

The ultrastructural characteristics of galactosaemic human fibroblasts exposed to media with various sugars were compared. Considerations of known biochemical pathways suggested that cells without the galactokinase enzyme and exposed to galactose would be functionally equivalent to cells in a medium without any sugar source. We found the ultrastructural characteristics of such cells to be consistent with that hypothesis. In addition, we unexpectedly found that homozygous galactosaemic fibroblasts, exposed to medium with glucose as the energy source, showed evidence of degeneration, such as autophagic vacuoles. Degenerative changes were not found in fibroblasts heterozygous for the galactokinase enzyme exposed to glucose. The implications and uses of these findings are discussed.