Effects of 6-mercaptopurine on developing muscle cells in vitro

Treating differentiating muscle cells in vitro with 6-MP has resulted in a number of myopathic changes, some of which resemble the changes seen in 6-MP-treated neonatal rats. 6-MP treatment was cytotoxic to myotubes, but not myoblasts. The degenerative changes observed in 6-MP-treated myotubes were quite similar to those described in the neonatal rats by Alleva and his colleagues (1981). The results of this investigation demonstrate that differentiating muscle grown in vitro can be used to investigate tissue-specific toxicity, although the mechanism by which 6-MP results in selective toxicity in myotubes remains to be elucidated.