VITAMINS

Rats maintained on a folate-free diet showed macrocytic anemia, leukopenia and increase of hypersegmented neutrophil after 2 weeks. These hematological changes became more prominent at the 4th and 6th weeks. Increase in body weight was delayed remarkably at both weeks. Folate contents in plasma, red blood cell and liver were estimated at the 2nd and 4th weeks. Low plasma and liver folate levels were observed at 2nd week and they were declined at 4th week. In red cell folate level, no decline was observed at 4th week although the value was significantly lower than that of controls. After 6th week, tetrahydrofolic acid was injected intraperitoneally 0.1 mg/g twice a week. The hematological examinations after 2 weeks showed increase of red cells and leukocytes and disappearance of hypersegmented neutrophils. Body weight was also increased through tetrahydrofolic acid.

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The successful separation of α, β+γ and δ-tocopherol was obtained by gel filtration through a column of Sephadex LH-20 using chloroform as an eluting solvent. The values of partition coefficient KD of tocopherols and their acetylated products were determined. It was observed that β, γ and δ-tocopherol showed a marked retardation on Sephadex LH-20 due to the presence of hydroxyl group and that the separation of tocopherols were affected by the structures rather than on the molecular size of the substances.

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The effect of six kinds of commercial polyphosphates to oxidation of ascorbic acid and sodium ascorbate (1mM) solutions in the presence of 32μg% Cu^<2+>, was investigated. The stabilizing abilities of these polyphosphates were grouped into three classes, that is, extremely excellent, moderate, and almost ineffective. Consequently, the use of the polyphosphates, sold on the market nowadays, to prevent oxidation of ascorbic acid should be paid attention to these phenomena.

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The uptake of ^3H-pyridoxol (^3H-POL) by rat intestinal tissues was investigated at a range of 0.1〜4μM concentrations of the vitamin by the everted intestinal ring method. On incubation at 37℃ for 5 min the intracellular concentration of the total radioactive materials was increased proportionally to the external ^3H-POL concentration. On the other hand, incubation at 37℃ for 60 min resulted in an intracellular accumulation of the radioactive materials against the concentration gradient. The ratio of intracellular to extracellular concentration of the labeled compounds was high at low external concentrations and diminished as the external concentration increased but was constantly higher than unity. By lowering the temperature of incubation to 0℃ or addition of 4-deoxypyridoxol (DOPOL) the uptake was appreciably inhibited. The inhibition by DOPOL was much more remarkable in the uptake during 60 min incubation than that during 5 min incubation. It was also found that a certain uptake could occur, independent of the inhibition, even at an infinitive deoxypyridoxol concentration. ^8H-POL taken up into the intracellular space was metabolized rapidly to pyridoxol phosphate (POLP), pyridoxal phosphate (PALP) and pyridoxamine phosphate (PAMP) to be accumulated. The addition of DOPOL led to a marked inhibition of B_6 phosphorylation and increase of free POL. From these results it is concluded that ^3H-POL enters the intracellular space physicochemically and is accumulated by the metabolic conversions to POLP, PALP and PAMP, which seem to be a concentrative accumulation.

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