Phenylhydrazine administered to rats at a dose of 4 mg/100g body weight per day for 3 days, diminished the total ascorbic acid level in liver, kidney and spleen tissues. The total ascorbic acid level in blood was, however, elevated after phenylhydrazine treatment. The other effects of phenylhydrazine treatment were a reduction in the activities of Dglucuronoreductase, L-gulonooxidase, dehydroascorbatase and uronolactonase in liver. The dehydroascorbatase activity in kidney was also diminished after phenylhydrazine treatment. The changes in the activities of liver enzymes were found to be accompanied by a diminution in the level of reduced ascorbic acid and an elevation in the dehydroascorbic acid level. It was concluded that the biosynthesis of L-ascorbic acid from both Dglucuronolactone and L-gulonolactone as substrates, was reduced in phenylhydrazine-treated rats. The degradation of L-ascorbic acid by both liver and kidney was diminished by the phenylhydrazine treatment. It was further concluded that phenylhydrazine-treated rats tried to conserve the level of substrate for the synthesis of L-ascorbic acid, by reducing the hydrolytic cleavage of D-glucuronolactone. The elevated blood ascorbic acid level under the same condition was ascribed to the diminished catabolism of L-ascorbic acid.

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The influences of dietary a-tocopherol, in combination with three different levels of linoleate (low, moderate or high levels), on the concentrations of plasma and liver lipids in rats were examined. Male Wistar rats were fed diets ad libitum for 2 weeks. dl-α-Tocopheryl acetate was added to the diets in 0, 20 or 200mg tocopherol/100g diet. The following results were obtained.
(1) Higher dietary levels of α-tocopherol tended to cause higher plasma lipid levels in proportion to the amounts added. This phenomenon is most remarkable in rats fed a diet containing cholesterol and low linoleate (0.8% of calorie).
(2) The concentrations of plasma lipids were influenced significantly than those of liver lipids by the levels of a-tocopherol under the conditions of this experiment.

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As one of the attempts to find clues on precursors or intermediates of the vitamin B₆ biosynthetic pathway, the resting cell system of Flavobacterium sp. 238-7, a bacterium producing a high amount of the vitamin, was employed. Among various compounds tested as an additive to the reaction mixture, L-glutamate and nucleoside derivatives increased the formation of vitamin B₆, respectively. The possible mech anism of the participation of these compounds in vitamin B₆ biosynthesis is discussed. The identification of vitamin B₆ formed in the reaction mixture was done using column chromatography.

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In vitro effect of cadmium on vitamin D-stimulated calcium transport in the rat was studied using the everted gut sac technique. Calcium transport was significantly inhibited by the addition of cadmium to the mucosal incubation medium. Furthermore, the kinetic analysis of in hibitory effect of cadmium on calcium transport revealed that the type of inhibition was competitive. The apparent “Km” and “V_max” value for calcium was 1.0 mM, and 2.86 μmoles ml^-1 ⋅hr^-1, respectively. An apparent “K_i” for cadmium was 0.02mM

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Following a previous report on physicochemical properties, the enzymological properties of a homogeneously purified preparation of pantothenate synthetase were described. The optimum pH was 10.0 and optimum temperature 30°C. The lyophilized enzyme was very stable on standing at -20°C. K⁺ or NH₄⁺ and Mg²⁺ or Mn²⁺ were required as activators; other cations examined were inhibitive to various extents and the enzyme required ATP as the energy supplier. Some co-amino acids exerted strong inhibition, and the enzyme was inhibited by some chelating agents but was not affected by SH compounds and SH inhibitors. Apparent Km for pantoate was 6.3×10^-5M, for β-alanine 1.5×10^-4 M, and for ATP 1.0×10^-4M, According to the method of CLELAND, the enzyme reaction proceeds by a Bi Uni Uni Bi Ping Pong mechanism and a scheme showing the order of binding of substrates and releasing of products is presented.

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Many mice treated with a high single dose of PL died in convulsions. The convulsions were very similar to those induced with some anti B₆ in several ways: (1) a long latent period occurs before convulsions; (2) PLP levels in brain decrease; (3) GABA levels in brain, especially in synaptosomal fraction, decrease. The possibility that a deranged GABA metabolism in nerve ending may be a major cause of the convulsions is discussed.

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The action of two types of ascorbate-related reductones on nucleic acids was investigated by comparison with that of ascorbic acid (AsA). Amino reductone (ScA) and thiol reductone (MHC) caused strandscissions in nucleic acids. This was confirmed by the fact that reductones lowered the viscosity of DNA solution and shifted the peaks of DNA and RNA to the low molecular side in centrifugal profile. Cue²⁺ strengthened their action as in the case of enediol reductones. The breaking activity of thiol reductone is relatively weak compared with those of amino and enediol reductones, The preferential degradation of apurinic acid was caused with amino and thiol reductones, suggesting that pyrimidine clusters in nucleic acids were susceptible to breakage.

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Disaccharidases activities in 20-day-old chick embryonic intestine were induced by the addition of sucrose, maltose, fructose and glucose to the culture medium. However, maltitol, which cannot be digested by intestinal enzymes, showed no effect on the induction of disaccharidase activity.
Kinetic study of the enzymes demonstrated that the maximum velocity (V_max) and the Michaelis constant (Km) of sucrose induced disaccharidases activities of the explants showed changes similar to those observed in the chick of same developmental stage in vivo. Namely, V_max values of sucrase and maltase were increased. Km values of sucrase did not change, but that of maltase showed a significant decrease during development.

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Anserine and carnosine in the muscle of growing rats were measured to explore the effect of dietary methionine. Carnosine was reduced in the gastrocnemius muscle of rats fed on a methionine-free diet. After refeeding on methionine for one week, carnosine in the muscle approached to the normal level. In contrast, anserine increased in the muscle of rats fed on a methionine-free diet. Anserine also increased in the gastrocnemius muscle of rats fed on a methionine-excess diet, whereas carnosine did not vary. N^π-Methylhistidine was detected in the muscle of rats fed on a methionine-excess diet. Moreover, N^π-methylhistidine and Nt methylhistidine in the urine increased in the rats fed on both methionine excess and methionine-free diets. Carnosine in the gastrocnemius muscle was not affected by a ethionine diet nor by a orotic acid diet which induced fatty liver. However, anserine increased in the muscle of rats fed on a ethionine diet.

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Serum cholesterol, triglyceride, phospholipid, total lipid and weight to height ratio were studied in 172 individuals from Bangkok, mainly university staff, and in 247 individuals from rural areas of northeast Thailand. Total lipid and phospholipid levels were statistically significant higher and triglyceride lower in the Bangkok group compared with the group from the rural areas. A cholesterol level did not differ significantly between the groups. The results are discussed in respect of a possible difference in the nutritional status between the individuals from the urban and rural area.

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Hematological changes due to protein deprivation were studied in 34 young Japanese men who were given a standard diet with an N intake of 200 mg/kg for one week and then low-protein diets with maintenance (45±2 kcal/kg) or excess (57±2 kcal/kg) energy and N intakes of about 44 to 99mg/kg of whole egg or about 50 to 121mg/kg of polished rice for three weeks. In the period of the low-protein diet the concentrations of most individual free plasma essential amino acids (EAA) decreased significantly in general, and thus the total FAA concentration decreased significantly. Lowering of the valine concentration and elevation of the alanine concentration were the highest changes. The total non essential amino acid (NEAA) concentration increased significantly in men fed a low-rice-protein diet, but not in those fed a low-egg-protein diet. Consequently, in the former group the ratio of essential to nonessential amino acids fell significantly from 0.96 in the control period to 0.61-0.74 in the period of consuming the low-protein diet. The effect of protein deprivation on the plasma EAA concentration was also larger with egg protein than with rice protein, and the total FAA concentration of men fed egg protein changed significantly and in parallel with the N intake over the range of 44 to 99mg/kg. The decreases in serine and threonine and increase in alanine tended to be more when energy intake was over the maintenance level. The concentration of plasma proteins and especially albumin decreased significantly during the period of consuming the low-protein diet. The interrelation of plasma-free amino acids, the amino acid pool in tissues and dietary N and energy intakes is briefly discussed.

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The possibility that there is some common factor in protein deprivation and splenectomy affecting the properties of red cells was examined by measuring the lipid contents of the plasma and red cells, the surface area and spherical index of red cells, and the lecithin cholesterol acyltransferase (LCAT) activity of the plasma in intact and splenectomized rats on diets with various levels of protein.
Results showed that splenectomy markedly reduced the osmotic fragility and increased the lipid content and surface area of the red cells of all dietary groups, and that decrease in the protein content of the diet gradually reduced the osmotic fragility and increased the lipid content of the red cells. A significant linear correlation was observed between osmotic fragility and the lipid content of red cells. LCAT did not influence the cholesterol level in red cell membranes because its activity in the plasma was not affected by either splenectomy or the protein content of the diet. A protein-free diet induced normocytic anemia, but increased the lipid content and reduced the osmotic fragility of red cells. Therefore, the effect of cholesterol in increasing the surface area of red cells was not proportional in the red cells of rats on a protein-free diet.
The present studies suggest that the mechanism of accumulation of cholesterol in red cells is different in protein deprivation and splenectomy. That is, in protein deprivation, increase in red cell cholesterol may result from decreased esterification of cholesterol in the plasma becaase of the low concentration of the substrate of LCAT, high density lipoprotein; and in splenectomized rats, the cholesterol level of the cells may not be reduced because the red cells are not exposed to the red pulp of the spleen where the pH is very low. These possibilities are supported by the finding that the osmotic fragility of the red cells decreased most and the lipid content of the cells increased most in splenectomized rats on a protein-free diet.

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It has been known that the intestinal epithelial cell is characterized by a rapid cell turnover and by a gradient of differentiation from crypt to villas. The present study was undertaken to clarity the effect of diet on the migration and the maturation of the intestinal epithelial cells. The transit time from the crypt to the extrusion zone at the villus tip was determined with tritiated thymidine. To study the maturation of the cells the distribution of the terminal digestive enzymes, maltase [EC 3. 2. 1. 20] and leucylnaphthylamidase [EC 3. 4. 1. 1], along the villus and crypt was analyzed quantitatively. And total activities of the same enzymes were assayed also in the mucosal homogenates. It was observed that the decrease in the migrating speed of villus cells was brought by energy restriction and the decrease in the migrating speed was associated with an increase of the enzyme activities in the upper zone of villus. And the result was that the intestinal epithelial cells which decrease in migrating speed by dietary restriction become more mature on the upper villus than those with unrestricted control.

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