The excretion of AsS and total vitamin C into urine after oral administration of AsS to humans was investigated. When 10 mmol of AsS was administered to the subjects, the excretion of AsS into urine continued for 60 hr in males and 48 hr in females. The average amount excreted per hour was less than 5mg. These results differed from those for AsA and DAsA orally administered to humans. The determination of vitamin C after oral administration of AsS to the subjects consisting of ten males and six females showed no vitamin C effect in humans, similarly to the case with the guinea pig and the rhesus monkey.

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The effect of dietary composition on the kinetic constants of intestinal lactase was studied using rats depleted of protein by feeding protein-free diet from the weanling stage to 34 days of age and sub-sequently allowed to recover on diets containing 11.5 or 17% of protein calories (P%) and different levels of lactose (L%;1, 15, 27 and 37%). After four days of refeeding, rats were decapitated and lactase activity was determined at different substrate concentrations by the method of Dahlqvist using homogenate of intestinal mucosa. Maximum velocity (Vmax) and Michaelis constant (Kr) were calculated according to Eisenthal and Cornish-Bowden. At both levels of P%, Vmax tended to increase with the dietary lactose concentration. With diets containing 37% lactose, at P% 11 Vmax was about 6000 of that at P% 17.0. Km tended to increase with L% in groups given the 17.0% protein calorie diets, but no difference was observed between groups fed at the lower level of protein. These results can be explained on the basis of interactions between dietary protein at different concentrations and inducer substrate which results in changes in isoenzyme patterns.

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Mechanisms of the adverse effects of dietary Tween 20, Tween 60, Span 20, sodium taurocholate (NaTC), sodium deoxycholate (DOG), sodium laurylbenzene sulfonate (LBS) and sodium dodecyl sulfate (SDS), and of the ameliorating effect of the concurrent feeding of dietary fiber were investigated along with releases of the hydrolase activities, which were localized in the brush border membrane of rat small intestine, during a jejunum perfusion in vivo. The releases of sucrase, maltase and alkaline phosphatase activities from the jejunum with Ringer bicarbonate solution (RBS) perfusion for 150 min proceeded at a constant rate after RBS perfusion for the first 30 min. The detergents were perfused after RBS perfusion for 60 min. In Tween 20-or 60-RBS perfusion at the 2% level, the released sucrase activity gradually increased, reaching a level 3 times that with RBS perfusion 90 min after the beginning of Tween 20-or Tween 60-RBS perfusion. With NaTC-or DOC-RBS perfusion at the 0.500 or 0.2% level respectively, the released sucrase activity reached a level 3 to 4 times that with RBS perfusion within 30 min of the beginning of NaTC-or DOC-RBS perfusion, but that with Span 20-RBS perfusion at the 2% level was slightly lower compared with that with RBS perfusion. On the other hand, with SDS- or LBS-RBS perfusion at the 0.5% level, the released alkaline phosphatase activity rapidly reached a level 3 to 4 times as high as that with RBS perfusion. The inclusion of Gobo dietary fiber at the 0.04% level with Tween 20-RBS perfusion completely eliminated the releasing effect of Tween 20 on sucrase activity. These results suggest that the primary cause of the adverse effects of the feeding of these detergents is the exfoliating or releasing effect thereof on the brush border membrane, together with the inhibitory effect of some of these detergents on intestinal disaccharidase activities, and that the dietary fiber prevents the exfoliating or releasing effects of several detergents on the brush border membrane.

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Weanling rats (weaned 12 days after birth) were fed on nicotinic acid-deficient and on nicotinic acid-supplemented diet separately for 7 and 21 days. The yield of myelin in the brain of rat fed on the nicotinic acid-deficient diet was lower than that in the case of receipt of the nicotinic acid-supplemented diet at 19, 26 and 33 days of age. Despite the changing yield of myelin, the proportion of protein and total lipids, and the percentage composition of lipid were not changed between the groups fed on the nicotinic acid-deficient and the nicotinic acid-supplemented diet. Moreover, the ratio of long chain fatty acid (C_{20_23}/C_{14_18}) was markedly decreased in the nicotinic acid-deficient rats. These findings imply that nicotinic acid may play an important role in myelination associated with the synthesis of cerebrosides which contain high levels of long chain fatty acid.

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To determine the effect of a certain diet on the intestinal flora of chicks, the cecal flora of chicks fed on a low protein or low lysine diet was examined. The cecal flora of chicks fed on the low protein diet was similar to that of chicks fed on a normal protein diet, but the total count of bacteria, Eubacterium and Enterobacteriaceae in the cecal content of chicks fed on the low lysine diet containing a formulated amino acid mixture minus lysine was significantly lower than that of chicks fed on the control diet. The total count of Lactobacillus in the cecum was remarkably reduced by feeding the amino acid diet, especially the low lysine diet. Levels of most free amino acids in the cecal contents of the low protein group were significantly lower than those of the control. Lysine, leucine, phenyl-alanine, methionine, histidine, glycine and tyrosine of the cecal contents in the low lysine group were significantly lower than those of the control group.

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Fatty acids of winged bean seed oil were examined by gas chromatography-mass spectrometry of their pyrrolidide derivatives. Oleic and linoleic acids were determined to be the major unsaturated fatty acids in the oil. Long chain saturated fatty acids, such as behenic and lignoceric acids, were found in relatively high amounts as compared with other edible seed oils. The fatty acids that could not be separated by gas liquid chromatography were identified as linolenic acid and arachidic acid respectively on mass spectrometric analysis. Parinaric acid, previously reported by Cerny et at., was not detected and this supposed fraction was instead found to be eicosenoic acid. Erucic acid, suspected of having an adverse effect on myocardial lesions in rats, was detected but only in small quantity. The identifications of these unsaturated fatty acids were further confirmed by deducing the location of the double bonds in their moieties. From these findings, winged bean seed oil can be suggested as being a food source of favorable quality.

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The effect of different dietary purines on the metabolism of serum and urinary uric acid, allantoin, creatinine, urea nitrogen and urea was examined in the rat. Experimental diets were synthetic and they were given ad libitum during a 6-day experimental period. The results were compared with the renal morphological changes.
The results obtained were as follows: Hypoxanthine, inosine, guanosine and guanine were readily converted to uric acid and allantoin, whereas adenine was metabolized quite differently from other purines. In partic-ular, the intake of adenine exhibited a decrease of the uric acid excreted in the urine. Furthermore, an increase of creatinine, urea nitrogen and urea in the serum as well as a reduction in their urine excretion were observed in rats fed on the adenine diet. Adenine produced a nephrotoxic condition as reflected in the histological changes.
From these observations, it is concluded that although the administered purines are closely related structurally, they are metabolized in so many different ways that some of the metabolites, particularly of adenine, may cause a potential nephrotoxicity.

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The effects of aging on enzyme qualities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were investigated. The Ouchterlony double-diffusion pattern showed that the enzymes from livers of rats of different ages are immunologically similar to each other. In addition, immunochemical titration demon-strated that the changes in the levels of activity of rats of different age are accompanied by proportionate changes in the quantity of the enzyme protein. The K_ms of the enzymes for substrates were not altered by aging. It is suggested that the age-dependent impairments of the enzyme induction (Iritani, N., Fukuda, H., and Fukuda, E. (1981) Biochim. Biophys. Acta, 665, 639) can be ascribed to decreases in the rise of enzyme protein quantities.

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The Ca²⁺-binding properties and amino acid compositions of two calcium-binding proteins (mCaBP-3 and mCaBP-4) purified fromff bovine milk were studied. mCaBP-3 was identified as a Cat +-bound type and mCaBP-4 as a Ca²⁺-free type by means of ion-exchange chromatog-raphy on a DEAE-5ephadex A-25 column. In polyacrylamide gel disc electrophoresis, both mCaBP-3 and mCaBP-4 had the same mobility of Rf=0.73 and the addition of 5 mM CaCl₂ to the electrode buffer decreased the mobility from R f=0.73 to R f=0.49. mCaBP-3 and mCaBP-4 con-sisted of 120 and 122 amino acid residues, respectively. The molecular weights were 13, 758 and 13, 967, respectively. The amino acid com-positions of the two milk CaBPs very closely resembled each other. Both milk CaBPs were rich in aspartic acid, glutamic acid, leucine and lysine, but did not contain trimethylated lysine and amino sugar. An interesting feature is that each milk CaBP contained eight cysteine sulfone and three tryptophan residues per molecule. From these results, it is suggested thal mCaBP-3 and mCaBP-4 are identical protein and that mCaBP-3 is formed from mCaBP-4 by means of a conformational change by binding of Cat + Thus, mCaBP-3 is a holoprotein and mCaBP-4 is an apoprotein. Furthermore, it is suggested that milk CaBP is different from calmodulin, troponin C and vitamin D-dependent calcium-binding protein.

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Thirteen Fischer strain rats were divided randomly into 3 groups soon after became pregnant and fed a 10%, 18%, or 36% casein diet throughout pregnancy and lactation. At weaning, female pups from the dams were divided into 3 further groups which were fed throughout life 10%, 18%, or 36% casein diet. The animals were weighed regularly and given a full autopsy after death. DNA was determined in the cerebrum and cerebellum of progeny at 7, 15 and 50 weeks of age respectively. The level of protein intake of the dams did not affect the litter-size, but did affect the body weight of pups at weaning. When fed a high protein diet after weaning, pups from dams fed a low protein diet weighed less throughout life than those from dams fed a high protein diet. A similar effect of protein intake was observed on the tail length. Pups of dams fed a low protein diet ate a larger amount of diet per unit body weight after weaning than those of dams fed at a high level of protein. Pups at 7, 15, and 50 weeks of age respectively from dams fed 1000 casein diet had a lighter cerebrum and cerebellum than pups of the same ages from dams fed respectively 18% and 36% casein diet. They also had less total DNA in the cerebrum and cerebellum than the latter. At the ages of 1 and 2 years respectively, the survival rates of rats fed the same diet as their mothers tended to be greater than those of rats fed diet different from that of their mothers. They also tended to live longer than the latter: 4 of 60 rats lived for over 1, 000 days, and 3 of these were fed the same diet as that of their mothers. Lesions observed at death did not differ in different groups. However, the incidence of lesions of the kidney and the number of tumors seemed to be greater in groups fed a high protein diet.

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The effects of diets, each with an excess of one essential amino acid, on the maintenance of pregnancy and fetal growth were investigated in rats. Rats were fed on 6% casein diet containing 5%, threonine, methionine, valine, isoleucine, leucine, tyrosine, phenylalanine, tryptophan, or lysine from day 1 to day 14 or 21 of pregnancy. Excess methionine and leucine diets resulted in complete and 80% loss of fetuses, respectively. This fetal wastage was prevented by daily injection of 0.5μg of estrone and 4 mg of progesterone. Judging from the total food consumptions and body weight gains during pregnancy, methionine had the most severe effects, followed in order by leucine, tryptophan, valine, lysine, isoleucine, threonine, phenylalanine, and tyrosine. The weights of fetuses in the excess amino acid groups were significantly lower than those in the respective pair-fed controls. Excess aromatic amino acids caused growth retardation of fetal brain, although the levels of free tyrosine and phenylalanine in fetal brain were not high. The concentrations of free methionine and threonine were markedly elevated in the maternal plasma when these amino acids were fed in excess, but those of other amino acids were not increased appreciably by excess amounts in the diet. Changes in the maternal plasma levels of individual amino acids other than those in excess in the diet were small. On the contrary, the levels of not only the excess amino acids but also of other amino acids in fetal brains were appreciably elevated by these diets. These findings suggest that the blood-brain barrier is immature and that the synthesis of proteins in fetal brain is impaired by excess amino acids in the mothers. The importance of experiments on diets with excess of single amino acids in pregnant animals is discussed in connection with studies on inborn errors of amino acid metabolism.

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