Ergothioneine Depletion in Rabbit Erythrocytes and Its Effect on Methemoglobin Formation and Reversion

Recent studies on methemoglobin (MHb) formation and reduction in nitrite—treated rabbit erythrocytes revealed an acceleration in both the appearance and reversion of MHb in red cells of animals raised on a purified diet. Liver paste added to this diet retarded the MHb formation rate but various crude supplements such as liver, yeast, wheat germ, and kale failed to alter the MHb reversion rate. Supplements of ergothioneine, glutathione, and vit. B12 have since been tested and it has been found that the ergothioneine retards MHb formation or reduction to a rate characteristic of corpuscles of animals raised on a stock diet. Moreover, the blood ergothioneine level varies inversely with the MHb rates, being low in rabbits on the purified diet and high in those fed the stock diet or treated with ergothioneine.procedure. Fifty male New Zealand strain albino rabbits weighing 1600-1800 g were placed on the purified diet designated as No. 672, while 12 animals were put on the stock diet composed of Purina rabbit pellets. Diet 672 contained sucrose, casein, cellophane, Wesson oil, O. M. salt mixture and vitamins as described previously. After 5 months the test rabbits were separated into 5 equal groups. Equal blood samples of the individuals in each group were pooled, and the rate of MHb formation was determined in the washed substrate—free erythrocytes following addition of a standard dose of NaNO2. This test and the determination of the rate of reversion of MHb after addition of a standard NaNO2 dose to corpuscles suspended in a medium containing lactate as substrate were carried out according to the procedure already outlined. Supplements of vit. B12, ergothioneine and glutathione, were then given three groups (Table I).