Inhibitory effects of tocopherol derivatives and ascorbic acid on the methemoglobin formation by nitrite ion in the blood of normal and acatalasemic mice

The inhibitory effects of tocopherol derivatives and ascorbic acid on methemoglobin formation by nitrite ion in the bloods of normal and acatalasemic mice were examined. Methemoglobin formation by nitrite ion was inhibited by tocopherol derivatives at final concentrations ranging from 0 to 500μM. Methemoglobin formation in the acatalasemic blood was higher than that in the normal blood at the same concentration of tocopherol derivatives. The inhibitory effects of tocopherol derivatives on the methemoglobin formation in the bloods of both normal and acatalasemic mice were in the descending order of d-α, dl-α, d-β, d-γ and d-δ. This is order coincides with the order of biological activity. Ascorbic acid inhibited methemoglobin formation by nitrite ion at the final concentrations ranging from 0 to 1.2 μM. The inhibitory effect of ascorbic acid was markedly lower than that of tocopherol. Methemoglobin formation in the acatalasemic blood was slightly higher than that in the normal blood at the same concentration of ascorbic acid