Chromatographic Separation and Microbiologic Assay of Vitamin B6 in Tissues from Normal and Vitamin B6-depleted Rats

Abstract

The Toepfer and Lehman assay for pyridoxine, pyridoxal and pyridoxamine was studied to determine optimal conditions of acid hydrolysis, sample size and volume of resin bed in order to apply it to animal tissues. Subsequent studies of B₆ vitamer content and transaminase activity in tissues obtained from vitamin B₆-deficient, ad libitum-fed control and pair-fed control rats showed that (a) total vitamer content of the tissues from the vitamin B₆-depleted rats was lower than that of the pair-fed and ad libitum controls; (b) highest levels of the total vitamer content were observed in the heart and muscle of the ad libitum controls; (c) total vitamer content of liver, kidney and brain of the ad libitum controls was intermediate between that of the pair-fed and deficient group; (d) similar total results were obtained when total vitamin B₆ was determined without chromatographic separation; (e) pyridoxine was noted in the lowest concentration in the rat tissues; (f) in all tissues except muscle, pyridoxamine was the vitamer found in highest concentrations, whereas pyridoxal was highest in muscle; (g) the values for tissue transaminase activity and vitamin B₆ content of liver and kidney of the pair-fed groups were higher than those for the ad libitum controls; and (h) the vitamin B₆ content of the brain of the pair-fed groups was higher than that for the ad libitum controls, but no difference was observed in the transaminase activity.