The inhibitory effect of liver catalase by 3-amino-s-triazole (3-AT) in vivo was observed commonly in mouse, rat, guinea pig and rabbit. The normal value of liver catalase activity is shown in the following order; guinea pig>rat≅mouse>rabbit and the inhibitory effect by 3-AT was found to be rabbit>mouse>rat>guinea pig, which was considered to be approximately in a reverse order.
Then, the related compounds to 3-AT in the chemical structure, such as 3-ureido-s-triazole (3-UT), 3, 5-diamino-s-triazole (3, 5-DAT), 4-amino-s-triazole hydrochloride (4-AT), Nitron, 5-amino-1, 2, 3, 4-tetrazole (5-ATT) and 2-amino-1, 3, 4-thiadiazole (2-ATD) were examined in its inhibitory effects. The strongest effect was found in the original compound, 3-AT, after which 3-UT and Nitron followed. Any inhibitory effect has not been observed in the rest of four compounds.