VITAMINS

The mutual effects of six kinds of commercial polyphosphates and of materials, exist in foods, to oxidation of ascorbic acid and sodium ascorbate solutions (1 mM) in the presence of 32μg% Cu^<2+>, were investigated. The mutual effects of their coexistence were as follows. That is, better, than the only material in foods, (peptone, glycine), worse, than the only material in foods, (sodium chloride, saccharin sodium), extremely bad (soluble starch, sodium benzoate), slight (sorbitol, sucrose), and the others (sodium glutamate, sodium dehydroacetate).

View full abstract

The inhibitory effect of hypocholesteraemic agents, 1-{2-[4'-(trifluoromethyl)-4-biphenyloxy] ethyl} pyrrolidine (Boxidine) and trans-1,4-bis-(2-chlorobenzylaminomethyl)-cyclohexane dihydrochloride (AY-9944), was studied on the Δ^<5,7>-sterol-Δ^7-reductase in rat liver. (1) Oral administration of Boxidine or AY-9944 resulted in the decrease of serum cholesterol and Δ^<5,7>-sterol-Δ^7-reductase activity. (2) Δ^<5,7>-Sterol-Δ^7-reductase was inhibited by Boxidine and AY-9944 also in vitro. (3) It was required, microsomes, cytoplasmic fraction (or sterol carrier protein=SCP) and NADPH to observe the enzymatic activity. Microsomes were affected by Boxidine and AY-9944. However, the binding of 7-dehydrocholesterol (7-DHC) to SCP was not influenced by these drugs, although vitamin D_3 decreased the Δ^<5,7>-sterol-Δ^7-reductase activity through the inhibition of the binding of 7-DHC to SCP. From these results, the possibility of Boxidine and AY-9944 was discussed in terms of tools for the study of the conversion of 7-DHC to vitamin D_3 in biological system.

View full abstract

When riboflavin 2', 3', 4', 5'-tetranicotinate (B_2-Nic) was added to rat liver homogenate previously irradiated with ultraviolet light, thiobarbituric acid value of the homogenate was decreased. This decrease depended on the concentration of B_2-Nic added and accompanied with the decrease in the amount of B_2-Nic. The presently observed effect of B_2-Nic was found to be ascribable to riboflavin part of B_2-Nic. Accordingly, it is considered that riboflavin part of B_2-Nic reacts with lipoperoxide, resulting in the mutual decomposition.

View full abstract

Show abstractHide abstract

Male DD mice were used. The dorsolateral area of mice was irradiated with ultraviolet (wavelength : 2,537 A) from a distance of 25 cm for 20 min and the creamy paste containing vehicle only (control group A) or the creamy paste containing vitamin E (experimental group D) was applied to the exposed area 7 times successively (1 min, 6,16,28,38,58 and 60h after the ultraviolet irradiation). Then, 12h after the last application of the creamy paste (72h after the ultraviolet irradiation) tissues were excised for light and electron microscopic observations. The results obtained are summarized as follows : 1) Light microscopic findings. It was found that pathological findings showing cellular damages in the epidermis such as intracellular edema, intercellular edema, parakeratosis etc. were most prominent in the group A and very slight or none in the group D. 2) Electron microscopic findings. Cytoplasmic alterations such as widening of the intercellular space, disappearance or disintegration of desmosomes, appearance of a large number of perinuclear vacuolation, swelling of some mitochondria, cytoplasmic damages, a decrease in number of keratohyalin granules, a slight decrease in the number of free ribosomes and an increase in the number of keratinosomes in the cytoplasm were prominent in the group A. In addition, in the group A a number of keratinosomes with lamellar patterns were observed in the intercellular space in the granular and parokeratotic layers, and furthermore the characteristic remnants such as nuclei, lipid-like granules, keratinosomes etc. were prominent in the parakeratotic layer. On the other hand, in the group D a slight thickening of the stratum corneum was sometimes observed, but the remnant of the nuclei etc. was rarely found, and by and large the organelles in the irradiated epidermal cells were close to normal except for a slight increase in number of keratinosomes. From the results obtained in the present investigation, it was concluded that vitamin E is effective in either protection or restoration of epidermal cellular damages due to ultraviolet irradiation, thus possesses an antiinflammatory action. The proposed mechanism of an antiinflammatory action of vitamin E was briefly discussed.

View full abstract

Download PDF (17527K)

Register with J-STAGE for free!