Methyl glyoxal bis guanylhydrazone abolition of the toxic action of spermidine on cells in culture.

Spermidine inhibits many cells in culture because amine oxidase in the serum converts spermidine to toxic products. Methyl glyoxal bis guanylhydrazone (Methyl GAG) inhibits cells in culture because it is a specific inhibitor of S-adenosylmethionine decarboxylase, preventing the conversion of putrescine to spermidine. When both spermidine and methyl GAG were added together, no inhibition was observed. The effect could be explained by the finding that methyl GAG was a powerful non-competitive inhibitor of the enzymatic oxidation of spermidine to acrolein.