Glyceraldehyde-3-phosphate dehydrogenase mRNA. Activity and amount in dystrophic hamster muscle.

The activity and amount of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in muscle of young dystrophic hamsters was reduced to approximately half the level found in control animals. No changes in brain or liver enzyme activity were found. Several other glycolytic enzyme activities and creatine kinase activity in muscle were unchanged, except for modest decreases in aldolase and pyruvate kinase. To assess the synthesis of glyceraldehyde-3-phosphate dehydrogenase, the poly(A)+ RNA was isolated from muscle polysomes of dystrophic and control animals and its activity was assessed in an mRNA-dependent translation system. The translatability of the mRNA for GAPDH found in the dystrophic muscle preparations also was half of that found in the control muscle preparations. Decreases were also found in the translatability of mRNA for tropomyosin.