bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of an adequate-protein diet after a low-protein diet on protein catabolism in growing rats
Authors: Horie Yoshimitsu , Ashida Kiyoshi 
Published: May 2005

1. Metabolic alterations related to protein catabolism were studied in rats in transitional states induced by changing from a low-protein (LP) (50 g casein/kg) diet to a high-protein (HP) (250 g casein/kg) diet.2. Twenty-four hours after the diet was changed, the rats showed a more rapid increase in live-weight gain than controls that had been fed on the HP diet throughout. On the 5th day after the diet change, their increase in body-weight had returned almost to the control rate. Food and therefore nitrogen intakes on the 1st and 5th days after the change in diet were the same as those of the controls. It seems likely therefore that the initial high rate of live-weight gain is an indication of a metabolic adaptation which occurred on the LP diet and which did not fully return to normal until the 5th day after the change of diet.3. N balance was higher 24 h after the change in diet than in the controls, owing to a reduction in total urinary N and in urea excretion, but when measured on the 5th day it was similar in both groups.4. Carcass N determination showed that, after 7 d on the LP diet total-, trichloroacetic acid (TCA)-soluble- and TCA-insoluble-N contents (in terms of mg/g rat) were all slightly lower than control values but they had almost returned to normal 5 d after the diet change. There was a significant increase in the TCA-soluble-N content after 24 h on the HP diet to a value greater than the control value.5. Proteolysis was measured in vitro by incubation of liver slices and diaphragms under anaerobic conditions. With liver slices it was significantly lower 24 h after the diet change than in control rats. On the 5th day it was significantly higher than 24 h after the diet change but had not quite reached the control level. In the diaphragm, proteolysis was also lower 1 d after the diet change, and had not increased at all by the 5th day.6. Ureogenesis in the liver was reduced significantly 24 h after the diet change and it had almost returned to the control level on the 5th day. On the other hand, arginase (L-arginine amidinohydrolase;EC3·5·3·1) activity was significantly lower 24 h after the diet change and did return completely to the control level on the 5th day.7. These results show that the initial increased N balance and reduced N excretion were due to enzymic adaptation to the LP diet, the reduced N excretion being attributable to reduction in hepatic urea production.
Degradation of riboflavin by alimentary bacteria of the ruminant and man: production of 7,8-dimethyl-10-carboxymethylisoalloxazine
Authors: West D. W. , Oiven E. C. 
Published: May 2005

1. A new product of the bacterial degradation of riboflavin has been isolated from fermentations in vitro of mixtures of either rumen bacteria or caecal bacteria with excess of the vitamin.2. This product has been identified as 7,8-dimethyl-10-carboxymethylisoalloxazine and has also been shown to occur in the urine of ruminants and man.3. The bacterial formation of this compound is compared with the bacterial formation of other isoalloxazines previously identified in similar incubation mixtures, and is discussed in relation to the factors influencing the mode of degradation of riboflavin.
Metabolism of riboflavin:reduction of 7,s-dimethyl-10-formylmethylisoalloxazine by an enzyme in liver
Authors: West D. W. , Owen E. C. 
Published: May 2005

1. The riboflavin metabolite, 7,8-dimethyl-10-formylmethylisoalloxazine, has been shown to be reduced to the corresponding alcohol, 7,8-dimethyl-10-(2′-hydroxyethyl)isoalloxazine, by an enzyme present in the soluble fraction of liver and kidney.2. The enzyme is present in these organs in a number of species but is especially prevalent in the tissues of ruminants. It appears to be different from the normal hepatic alcohol dehydrogenase in that it uses NADPH rather than NADH as cofactor.
Notes on a deamination method proposed for determining ‘chemically available lysine’ of proteins
Authors: Allison R. M. , Laird W. M. , Synge R. L. M. 
Published: May 2005

1. Details of a chemical method, using acetic acid and sodium nitrite, for determining ‘available lysine’ in plant materials are given. An analytical procedure was used which distinguished lysine from ornithine; the latter was liable to arise in the course of the deamination and hydrolysis procedure.2. The experimentally determined ‘available lysine’ contents of various samples of leaf-protein concentrates showed significant positive correlations with previously reported values for their biological value and true digestibility. ‘Available lysine’correlated significantly with total lysine liberated by direct acid hydrolysis.
Relationships between copper, zinc and iron in the plasma, soft tissues and skeleton of the rat during Cu deficiency
Authors: Alfaro Begona , Heaton F. W. 
Published: May 2005

1. The effect of dietary copper deficiency on the distribution of Cu, zinc and iron between plasma, various soft tissues and bone was investigated in weanling male rats.2. The concentration of Cu decreased in plasma, liver, kidney and femur, and the concentration in plasma correlated with that in all three organs. The total amount of Cu in the liver was reduced over the whole depletion period and a net loss from kidney also occurred over a shorter period, indicating that liver and, to a lesser extent, kidney both provide a mobilizable reserve of Cu.3. Animals in galvanized cages developed Cu deficiency more rapidly than similar rats in stainless-steel cages owing to Zn aggravating the depletion. Zn accumulated in the liver and femur of Cu deficient rats, particularly when they were housed in galvanized cages.4. Cu-deficient animals accumulated Fe in the liver, but had reduced concentrations in plasma, kidney and spleen. The hypertrophy of the heart and bone-marrow observed in Cu-deficient rats appeared to be secondary to the anaemia resulting from this impaired mobilization of hepatic Fe.
Short-term effects of feeding rats with glucose syrup fractions and dextrose
Authors: Birch G. G. , Etheridge I. J. , Green L. F. 
Published: May 2005

1. Young female Wistar rats were fed for 18 d on diets containing dextrose, 43 dextrose equivalent (DE) glucose syrup, fractions of 43 DE glucose syrup of high and low molecular weight or sucrose.2. All rats gained weight and showed no gross external abnormalities or significant dental caries scores.3. The concentrations of cholesterol, triglycerides, free fatty acids and glucose were determined in samples of liver and serum. Generally, these values tended to increase with increasing molecular weight of dietary carbohydrate in the order dextrose, glucose syrup fraction of low molecular weight, and glucose syrup fraction of high molecular weight.4. Rats given the high-molecular weight glucose syrup fraction were found to have caecums twice the normal size.
Lesions produced by copper deficiency in neonate and older rats
Authors: Hall G. A. , Howell J. McC. 
Published: May 2005

1. Three groups of rats of different mean weights were given a diet of milk treated with hydrogen sulphide and supplemented with copper-free minerals and vitamins. Also divided into three groups of similar weights were rats given the same diet supplemented with 500 μg Cu/week and stock rats which were given a commercial diet.2. In a second experiment eight adult female rats were given the Cu-deficient diet for 2 weeks before mating and during pregnancy, and in a third experiment were mated and immediately after mating were given the Cu-deficient diet or the Cu-supplemented diet.3. Cu deficiency reduced the growth rate of younger rats but had a much less marked effect on the weight of more mature rats. Achromotrichia appeared at 5 weeks; diarrhoea, with the faeces frequently containing undigested blood, and subcutaneous oedema were terminal changes. Deaths occurred in the youngest group of rats after 9 weeks and later in heavier, older rats.4. Histological changes were seen in livers, spleens, testes and epididymes but not in blood vessels or bones.5. Pups were not born to mothers given the deficient diet before mating, and the pups from mothers given the deficient diet only during pregnancy were born dead or showed congenital abnormalities.6. Foetal and liver Cu concentrations for the various groups of animals are given.7. Maintenance of the foetus appears to be the biological process most susceptible to Cu deficiency in the rat.
The composition of chinchilla milk
Authors: Volcani R. , Zisling Kivka , Sklan D. , Nitzan Zafrira 
Published: May 2005

1. The composition of the milk ofChinchilla chinchilla chinchillawas determined throughout lactation in twenty-eight chinchillas. The amino acid pattern of the protein and the fatty acid composition of the milk were determined, and the effect of three different diets on the milk composition was studied.2. The milk contained (g/kg): 64–80 protein, 108–156 fat, 17 lactose and 10 ash.3. Paper and polyacrilamide gel electrophoresis showed four additional protein fractions that are not apparent in bovine milk protein.
The effect of a low-fat maternal diet on neonatal rats
Authors: Sinclair A. J. , Crawford M. A. 
Published: May 2005

1. Rats were raised on a low-fat diet containing 6 g fat/kg. Females of the second generation were bred and only 11% of their pups survived to weaning age compared with a 66% survival for control pups. Pups were killed 8–12 h after birth and their tissues were analysed.2. Pups in the low-fat group had smaller body, brain and liver weights than control pups; the lipid contents of body, brain and liver were also significantly less.3. In the liver triglycerides from the control group the C20and C22polyenoic fatty acids constituted 33% of the total fatty acids. The liver triglyceride concentration in the low-fat group was lower and the concentration of the long-chain polyenoic fatty acids in this fraction was 20% of the control value. The milk fatty acids from the low-fat group contained only 33% as much of the C18to C22polyenoic fatty acids compared with the control group.4. In the brain lipids from the low-fat group, changes in the fatty acid composition were less marked than in the liver lipids. In these experiments there were only small amounts of 20:3ω9 in the tissue lipids; the ratio to 20:4ω6 was less than 1.5. These changes are discussed in relation to the influence of dietary lipids on tissue growth especially of lipid-rich tissues such as the brain.
The metabolism of some folates in the rat
Authors: Beavon J. R. G. , Blair J. A. 
Published: May 2005

1. A number of folates labelled with 14C were administered orally to rats, at various doses, and urinary, faecal and hepatic folates examined.2. 10-Formylpteroylmonoglutamic acid (10CHO—PGA) entered the folate pool very slowly, and is thought to be relatively ineffective in nutrition.3. 10-Formyl[2-14C]tetrahydrofolic acid (10CHO—[2-14C]THF) entered the folate pool very rapidly. 5-Methyl[2-14C]tetrahydrofolate (5CH3—[2-14C]THF) was the major urinary folate.4. 5-Formyl[2-14C]tetrahydrofolic acid (5CHO—[2-14C]THF) entered the folate pool only to a small extent. 5CHO—[2-14C]THF, given intravenously, produced no urinary 5CH3—[2-14C]THF in the first 6 h.5. 10-Methylidyne[2-14C]tetrahydrofolic acid was metabolized to an extent which was dependant on the dose. At doses of 3 and 30 μg/kg body-weight, 5CH3—[2-14C]THF represented 5·4 and 20% respectively of urinary folates and for 10CHO—[2-14]PGA, the values were 16% of total urinary folates after the higher dose, and 78·5% after the lower dose.6. Results obtained for the metabolism of 5CH3—THF varied depending on the position of the labelling: 514CH3–THF gave no labelled urinary folate, the methyl group being lost rapidly. When 5CH3—[2-14C]THF was given, it appeared as the major urinary folate.7. Folates found in the liver after oral administration of labelled folates were identified by thin-layer chromatography; only folate monoglutamates were identified.
Ascorbic acid and long-term anticonvulsant therapy in children
Authors: Dawson K. P. , Duncan Anne 
Published: May 2005

1. Forty-eight children, who were long-term hospital patients, were investigated to assess their leucocyte ascorbic acid status.2. Twenty-nine children had been receiving long-term anticonvulsant therapy, and these children did not have a significantly lower level of ascorbic acid than the untreated group, which did not have epilepsy.3. The ascorbic acid levels of all subjects were low and seventeen had levels between 7·3 and 16·0 μg/108 white blood cells.
The effect of different feeds, including those containing soya-bean products, on the passage of digesta from the abomasum of the preruminant calf
Authors: Smith R. H. , Sissons J. W. 
Published: May 2005

1. The effects of various factors on rates of flow and composition of digesta leaving the abomasum of preruminant calves were studied. The possible relation of some of these effects to the development of serum antibodies to certain dietary constituents has also been examined. Two situations were distinguished: (a) unsensitized responses, shown by calves receiving milk protein or soya-bean products for the first one or two occasions; (b) sensitized responses, shown by calves receiving certain soya-bean products, after a number of these feeds had been given.2. For unsensitized calves, the rate of flow of total digesta from the abomasum was greater in the first few hours after a feed consisting of a mineral solution was given, than after cow's milk was given. This difference was apparently due to differences in the composition of digesta entering the duodenum. Total digesta flows after giving synthetic milk feeds, prepared from different protein sources, were similar to those after cow's milk was given.3. For sensitized calves, rates of flow of total digesta from the abomasum were greatly affected by the nature of the protein source used in the diet. Soya-bean flour (heated or unheated) generally caused inhibition of flow for some hours after feeding; a soya-bean protein isolate (isoelectric) had a similar but smaller effect, but a soya-bean concentrate (prepared by alcohol extraction of a soya-bean flour) and milk protein had little or no effect. The inhibition, believed to be a sign of more general disorders, appeared to be caused by a factor entering the duodenum which induced a change in the way in which the calf responded, probably as the result of a gastrointestinal allergy.4. Calves given soya-bean flour or a soya-bean protein isolate (isoelectric) in their diets for several weeks, showed respectively high and low titres of serum antibodies to an antigen prepared from soya-bean flour. Calves given alcohol-extracted soya-bean concentrate had no similar antibodies.5. In addition to variations in total digesta flow, dietary nitrogen compounds were held up in the abomasum to different extents after different feeds. After a whole-milk feed or a synthetic feed prepared from casein, a slow, steady release of N occurred over at least 9 h. N hold-up after giving soya-bean-containing feeds was slight for the soya-bean flour, but extremely marked for the soya-bean protein isolate (isoelectric). The latter hold-up was followed after several hours by a rapid outflow of N from the abomasum.
The absorption of iron, with or without supplements of single amino acids and of ascorbic acid, in healthy and Fe-deficient children
Authors: El-Hawary M. F. S. , El-Shobaki F. A. , Kholeif T. , Sakr R. , El-Bassoussy M. 
Published: May 2005

1. Studies were done on the effect of ascorbic acid and five amino acids (histidine, cystine, cysteine, valine and glutamic acid) on intestinal iron absorption in a group of ninety Egyptian infants and young children, of which fifty-seven were healthy controls and thirty-three were suffering from Fe-deficiency anaemia.2. Supplements tested promoted Fe absorption in healthy controls in the following order: valine > histidine > ascorbic acid. Cysteine, glutamic acid and cystine were found to have no significant effect.3. Supplementation with valine, ascorbic acid and histidine also increased intestinal Fe absorption in anaemic subjects, but to a lesser extent than in controls.4. Supplementation of haematinic therapy with these compounds is recommended. Their use is also suggested to improve the availability of the Fe content of everyday diets.
An abnormality of the bone marrow associated with vitamin E deficiency in sheep
Authors: Kimber R. J. , Allen Shirley H. 
Published: May 2005

1. Sheep fed on a maintenance ration of wheaten-hay chaff or of wheaten-hay chaff–lucerne-hay chaff (1:1, w/w) became deficient or incipiently deficient in vitamin E.2. Degenerative changes were observed in bone marrow and muscle, and liver function was impaired in some animals. These abnormalities were not influenced by the vitamin B12status of the animals or by a shortage of cobalt in the rumen.3. Plasma ascorbic acid levels may not have been optimum, and folic acid may not have been fully utilized by some sheep.4. Liver function responded fairly rapidly to α-tocopheryl acetate, but skeletal muscle had not returned to normal after 28 weeks of treatment. A variable trend towards normal cellularity was found in bone marrow following supplementation with α-tocopheryl acetate.5. A secondary deficiency or, alternatively, inefficient excretion or metabolism of a toxic material, may occur in vitamin E deficiency as a result of degenerative changes in the absorptive or excretory areas of the intestinal tract and be responsible for the bone marrow abnormality.
Effect of different regimens of early malnutrition on behavioural development and adult avoidance learning in Swiss white mice
Authors: Bush Maureen , Leathwood P. D. 
Published: May 2005

1. The effects of perinatal malnutrition on behavioural development and adult shuttle-box avoidance performance were studied in Swiss white mice.2. Mice were malnourished (a) from the 7th day of gestation until birth, (b) from birth until weaning, or (c) during both gestation and the sucking period.3. Pups born of protein-restricted mothers had reduced birth weights, retarded development and poor adult avoidance performance, even if reared from birth by well-nourished mothers.4. Postnatal malnutrition, induced either by restricting maternal diet or by rearing in large litters, retarded development during the second half of lactation and lowered subsequent adult avoidance performance.
Effects of ingestion of organic selenium in adapted and non-adapted rats
Authors: Jaffe W. G. , Mondragon Cristina 
Published: May 2005

1. Rats were given moderate-selenium (4·5 mg/kg) or low-Se (0·5 mg/kg) diets during gestation and lactation. Their young were given diets with high (10 mg/kg), moderate or low Se contents from weaning, and groups of rats were killed at intervals during the 14-week experimental period.2. Compared with young rats which received the low-Se diet, those which received the moderate- or high-Se diets had a high incidence of liver lesions and there were changes in liver Se content, haemoglobin concentration, packed cell volume, prothrombin activity, fibrinogen content, spleen weight, body water and serum glutamic–oxaloacetic and glutamic–pyruvic transaminase (L-aspartate: 2-oxoglutarate aminotransferase; EC 2.6.I.I and L-alanine: 2-oxoglutarate aminotransferase; EC 2.6.I.2 respectively) and alkaline phosphatase (EC 3.I.3.I) activities. In those rats which received the high-Se diet the changes were more pronounced than in those which received the moderate-Se diet.3. In young rats from dams given moderate-Se diets, which were themselves given the moderate-Se diet, the liver Se content decreased continuously, whereas rats given the same diet but from dams which had received the low-Se diet, the liver Se content increased continuously. There was a slight improvement of symptoms of Se toxicity in all groups by the 5th week of the experimental period.4. The results suggest that there was an adaptation to chronic Se intake.
Effects of live weight and energy intake on nitrogen balance and total N requirements of lambs
Authors: Black J. L. , Griffiths D. A. 
Published: May 2005

1. Results of 298 nitrogen balance studies from experiments with male cross-bred lambs, ranging in weight from 3 to 38 kg, which had been either fasted, or fed entirely on liquid diets of varying protein content at various energy intakes up to ad lib. intake, were used to quantitatively describe the effects of the amount and quality of absorbed protein, energy intake and live weight on N balance and total N requirement of lambs.2. When N intake was less than the amount required, N balance was independent of energy intake, but linearly related to absorbed N and metabolic body-weight (live weight0·75). In the fitted relationship, the coefficient of absorbed N was shown to be an estimate of the biological value of absorbed protein and the coefficient of metabolic body-weight was an estimate of the loss of endogenous N in both urine and faeces. For the milk-based diets used in the experiment biological value was 0·72 and the total endogenous N loss in urine and faeces was 148 mg N/kg0·75 per d.3. When N intake was in excess of the amount required, N balance in lambs of a constant live weight increased linearly with metabolizable energy (ME) intake, at a rate that decreased with increasing live weight. Similarly at constant ME intake, N balance was a curvilinear decreasing function of metabolic body-weight. When N balance was expressed per unit metabolic body-weight, it was constant for lambs of all weights when ME intake was about 0·23 MJ/kg0·75 per d, but it decreased linearly with increasing metabolic body-weight for ME intakes above this level.4. N balance of fasted lambs was several times less than predicted by either of the relationships established for fed animals, and was found to be linearly related to metabolic body-weight.5. The effects of energy intake and live weight on the total N requirement of lambs were determined. When total N requirement was expressed per unit of energy intake, it was found to be constant at 0·9 g N/MJ ME for all lambs irrespective of live weight when ME intake was 0·23 MJ/kg0·7 per d. However, as ME intake/unit metabolic body-weight was raised above this level, N requirement/unit ME intake increased for lambs weighing less than c. 23 kg, but decreased for heavier animals.
Vitamin B12 nutrition and metabolism in the baboon (Papio cynocephalus)
Authors: Siddons R. C. , Jacob Fredericka 
Published: May 2005

1. Measurement of the vitamin B12 content of baboon tissues showed that the liver contained the highest concentration, followed by the pituitary, kidney, heart, spleen and pancreas.2. The dietary vitamin B12 requirement of the baboon for the maintenance of satisfactory body stores was between 1 and 2 μg/d.3. Satisfactory liver vitamin B12 stores were invariably associated with serum levels above 125 pg/ml, whereas liver levels were usually low when the serum level was below 50 pg/ml.4. Increased methylmalonic acid (MMA) excretion after a valine load occurred when the liver vitamin B12 level was less than 0·40 μg/g. L- and DL-valine were approximately equally effective as precursors of MMA, whereas sodium propionate, whether given orally or intra-peritoneally, was less effective.5. The distribution of radioactivity along the wall of the intestinal tract after an oral dose of [57Co]cyanocobalamin suggested that the distal half of the small intestine was the main site of vitamin B12 absorption. However, the utilization of vitamin B12 put direct into the middle part of the small intestine was much lower than that of an oral dose.6. The unsaturated vitamin B12-binding capacity of baboon serum was not related to the serum vitamin B12 level. There was a significant difference between the unsaturated vitamin B12-binding capacities of the two subspecies of baboon (Papio cynocephalus cynocephalus and P. cynocephalus anubis) studied.