1. The effects of cyanamide on alcohol dehydrogenase and aldehyde dehydrogenase were studied. 2. Cyanamide did not affect the activity of alcohol dehydrogenase. 3. Cyanamide inhibited aldehyde dehydrogenase noncompetitively to acetaldehyde as well as to the coenzyme. The authors wish to thank Dr. K. Yagi for his guidance and valuable criticisms.
