Abstract
It is generally recognized that INAH (isonicotinic acid hydrazide) competes with vitamin B_6. We investigated on this problem using the activities of several enzymes, such as GOT (glutamic oxaloacetic transaminase) and asmine oxidases, which contain pyridoxal phosphate as cofactor, as objects to be studied. INAH blocks liver GOT activity both in vivo and in vitro, and simultaneously it is presumed that INAH damages liver cells and lets GOT flow out of liver into blood stream. Amine oxidase activities in liver and in brain were not influenced by the addition of INAH in vitro. Ribonucleic acid in liver increases after the administration of pyridoxine and decreases after the administration of INAH. Furthermore, pyridoxine reduces the toxicity of INAH against animals.
