Ultrastructural changes in the mitochondria of intestinal epithelium of rodents treated with methylglyoxal-bis(guanylhydrazone).

Ultrastructural studies of rats or mice treated for 24 hr with a toxic dose (100 mg/kg) of methylglyoxal-bis(guanylhydrazone) revealed the presence of damaged mitochondria in the crypt cells of the intestinal epithelium. Mitochondria were severely swollen and electron lucent, and appeared to be similar to those observed previously in a variety of cell types treated in vitro and in vivo with methylglyoxal-bis(guanylhydrazone). Since thymidine incorporation into the intestine was not found to be decreased until after 24 hr, it is concluded that the mitochondrial damage of methylglyoxal-bis(guanylhydrazone) could be responsible for the antiproliferative toxicities of the drug.