bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vitamin E and stress
Authors: Cawthorne M. A. , Diplock A. T. , Muthy I. R. , Bunyan J. , Murrell Elspeth A. , Green J. 
Published: September 2005

1. Vitamin E-deficient rats were found to be more susceptible than vitamin E-supplemented controls to the toxic effects of hyperbaric oxygen (60 lb/in.2 for 20 min). This agrees with the findings of other workers.2. Hyperbaric O2 treatment did not increase the metabolic destruction of a small amount (46.65 μg) of [14C-5-Me]D-α-tocopherol given to adult vitamin E-deficient rats 24 h previously. The O2 treatment also did not affect the soluble sulphydryl compounds and ascorbic acid of rat liver, nor the percentag haemolysis in vivo of rat blood.3. Hyperbaric O2 treatment did not increase the true lipid peroxide content of rat brain, compared to control rats treated with hyperbaric air, which has no toxic effects. Increases in ‘lipid peroxidation’ reported by previous workers are considered to have been due to the use of inadequate controls (untreated rats) and of in vitro techniques that are open to criticism.4. The toxic effects of hyperbaric O2 in the vitamin E-deficient rat cannot be attributed to peroxidation in vivo.5. Vitamin E was not found to protect rats against the effects of reduced O2 tension (anoxic anoxia). This finding contrasts with some reports by earlier workers. Reduced O2 tension had no effect on the metabolism of radioactive tocopherol, on blood haemolysis in vivo, or on the soluble sulphydryl compounds and ascorbic acid of liver.
Vitamin E and stress
Authors: Diplock A. T. , Green J. , Bunyan J. , Cawthorne M. A. , Dawson Jean 
Published: September 2005

1. The effects of iron overloading and unsaturation of dietary lipid on the metabolism of α-tocopherol in the rat were studies.2. Young adult male vitamin E-deficient rats were given 1000 i.u. of vitamin A and 100 μg of [14C-5-Me]D-α-tocopherol and then given diets containing 5% methyl oleate or 5% cod-liver oil fatty-acid methyl esters. Rats from each group were given intramuscular injections of iron-dextran (50 mg Fe/kg rat) at 48 h intervals for 15 days, and compared with controls given dextran. After this time, liver, kidney and the remainder of the carcass were analysed for [14C]α-tocopherol, and liver and kidney were also analysed for vitamin A.3. There was no evidence that Fe overloading caused any increase in the destruction of either tocopherol or vitamin A in vivo, whether or not the diet contained polyunsaturated fatty acids. Indeed, treatment with Fe significantly decreased the metabolism of the radioactive tocopherol dose in all three tissues studied.4. These experiments show that the stress effect of Fe in the vitamin E-deficient animal is unrelated to an increase in oxidative reactions. They provide further evidence that ‘lipid peroxidation’ is not causally concerned in ‘anti-vitamin E’ stress conditions and that α-tocopherol does not function, in vivo, as an antioxidant.
Experimental resection of the intestine in newborn pigs
Authors: McCance R. A. , Wilkinson A. W. 
Published: September 2005

1. The whole of the lower half of the small intestine, with the exception of the last few cm of the ileum, has been removed from sixteen suckling pigs, 3–4 kg in weight.2. The operation is technically easy, but the exposure and handling of the intestines may produce crippling adhesions.3. The postoperative management presents no serious nutritional difficulties.4. If the operation is successful the animals become functionally normal, if slightly small, adults.
Zinc deficiency and the zinc requirements of calves and lambs
Authors: Mills C. F. , Dalgarno A. C. , Williams R. B. , Quarterman J. 
Published: September 2005

1. The effects of changes in zinc intake on weight gain, plasma Zn concentration and the development of clinical lesions of Zn deficiency have been studies in Zn depletion and repletion studies with calves and lambs.2. A basal diet, the principal components of which are urea, dried egg white, starch, glucose, cellulose and arachis oil has been developed for trace element deficiency studies with ruminants.3. Weight gain ceased abruptly in both calves and lambs when either the unsupplemented basal diet was given or when Zn supplements provided only 0.05 mg Zn/kg live weight per day. Mean plasma Zn concentrations in these animals fell from pre-experiment values of between 0.8 and 1.2 μg Zn/ml to below 0.4 μg Zn/ml after 1 week on these treatments.4. Supplements providing 0.2 mg Zn/kg live weight per day were sufficient to maintain a good rate of growth but insufficient to prevent a fall in plasma Zn.5. Growth arrest occurring within 2 weeks and a rapid fall in plasma Zn occurring within 1 week after Zn supplements were withheld from calves and lambs that had previously received 0.7 mg Zn/kg live weight per day for 6 and 14 weeks respectively indicated that these species have only a limited capacity to store Zn in a form that can be utilized during periods of inadequate Zn intake.6. Tentative estimates are presented of the Zn requirements of calves maintained on this type of basal diet and the influence of ration composition of Zn availability is discussed.7. The possible value and the limitations of plasma Zn determination as an aid to the field diagnosis of Zn deficiency are considered.
Continuous measurement of heart rate as an indicator of the energy expenditure of sheep
Authors: Webster A. J. F. 
Published: September 2005

1. The relationship between the heart rate and the energy expenditure of four sheep, S6, S7, S8 and S1, was studies under conditions known to increase energy metabolism.2. A close relationship between heart rate and energy expenditure was shown to exist in three of the four sheep tested when energy expenditure was increased by cold exposure and by increased levels of food intake.3. The source and magnitude of the errors associated with this relationship were studied by analysis of the variation occurring in the O2 pulse (ml O2/heart beat) of the sheep in response to factors other than those directly related to changes in heart rate. In two sheep, S8 and S6, variations in O2 pulse were random. The errors associated with the estimation, from heart rate measurements, of the energy expenditure of these sheep were ±6.8% and ±8.1% respectively. In the other two sheep, S7 and S1, O2 pulse tended to vary significantly during the experiments, in a way that was not directly related to changes in heart rate. The errors of the relationship in these sheep were ±8.6% and ±13.8% respectively.4. Indirect evidence was obtained to suggest that continuous measurements of heart rate continued to reflect with reasonable accuracy the energy expenditure of the three sheep, S6, S7 and S8 when they were standing and lying and when they were eating.5. Direct measurements were made of the O2 consumption and heart rate of sheep S7 and S1 during the act of eating. The energy expenditure of sheep S7 estimated from its O2 consumption was close to that estimated from measurements of its heart rate. Large errors were noted between these two estimates in sheep S1.6. It was concluded that sheep S8 and S6 would be suitable for long-term experiments designed to predict energy expenditure from heart rate measurements made in the field. Sheep S7 was considered to be of limited value for short-term experiments. Sheep S1 was considered to be unsuitable.
Blood copper as an indicator of copper status with a note on serum proteins and leucocyte counts in copper-deficient rats
Authors: Dreosti I. E. , Quicke G. V. 
Published: September 2005

1. Albumin, α1-, α2-, β- and γ-globulin fractions were demonstrated in serum from control and copper-depleted rats, but no quantitative difference was found in the distribution of the proteins between the two groups of animals. Both the total number of leucocytes and the number of polymorphonuclear leucocytes increased during copper depletion.2. Plasma copper content was found to be superior to whole blood copper content as an index of the copper status of rats at intermediate stages of depletion. The copper content of erythrocytes was found to be unaffected even in the severely depleted animals; this explains, in part, the poor response of whole blood copper content to intermediate stages of depletion.3. A single dose of orally administered copper was reflected in the plasma copper content of depleted rats about 12 h after dosing. No similar rise was observed in control animals, and the extent of the response was not increased by increasing the dose of copper.4. It is suggested that plasma copper response to a single oral dose of copper sulphate may provide a useful method for the detection of subnormal copper status in individual farm animals without the necessity of determining breed norms.
Studies on the composition of food
Authors: Harries J. M. , Hubbard A. W. , Alder F. E. , Kay M. , Williams D. R. 
Published: September 2005

1. An attempt has been made to compare the nutritive value of beef from intensively reared animals with that from more extensively reared stock.2. The difficulties of such a comparison are described and the consequent limitations of this experiment specified.3. It was found that samples of longissimus dorsi and superficial digital flexor muscles showed no significant differences between intensively reared and extensively reared animals in their content of moisture, intramuscular fat, protein, non-protein nitrogen, iron, thiamine, riboflavine, or nicotinic acid.4. The longissimus dorsi muscles had more non-protein nitrogen and more nicotinic acid, but less iron and less riboflavine, than the superficial digital flexor muscles.5. There was less vitamin A and less carotene in samples of liver from intensively reared animals than in comparable samples from extensively reared animals.
Rates of production of volatile fatty acids in the rumen of grazing sheep and their relation to ruminal concentrations
Authors: Leng R. A. , Corbett J. L. , Brett D. J. 
Published: September 2005

1. The rates of production, or entry rates, of acetic, propionic and butyric acids in the rumen of grazing sheep have been measured by a radioisotope technique previously used on penned animals.2. Regression equations were derived relating entry rates to ruminal concentrations. The equations from penned and grazing sheep did not differ significantly.3. The standard errors of entry rates predicted for a single sheep from equations based on all results were calculated to be ± 0·06, 0·18 and 0·15 m-mole/min for acetic, propionic and butyric acids respectively.4. Interconversions between acetic and butyric acids in the rumen were similar in extent to those found in penned sheep. These values were used to calculate from entry rates the net amounts of the acids becoming available to the animals.5. An equation was derived that permits the amount of energy supplied to an animal by the acids to be predicted from concentrations with a standard error of ± 0·17 kcal/min.6. The applicability of the prediction equations is discussed.
The contribution of propionate to glucose synthesis in sheep given diets of different grain content
Authors: Judson G. J. , Anderson Elizabeth , Luick J. R. , Leng R. A. 
Published: September 2005

1. Glucose entry rates into the blood and propionate production rates in the rumen have been measured in sheep given rations containing varying proportions of starch and roughage (lucerne).2. Glucose entry rates and propionate production rates were similar for all rations studied.3. The proportion of the glucose entry rate arising from propionate produced in the rumen was highest on the ration containing the greatest quantity of lucerne and decreased as the proportion of starch in the ration increased. Rate of conversion of propionate into glucose was estimated and was found to decrease as the amount of starch in the ration increased.4. Concentrations of total volatile fatty acids (VFA) in the ruminal fluid were lowest in the ration with the greatest proportion of starch, implying lower VFA production rates with the starch rations although intakes of digestible energy were approximately the same. The mean concentrations and rates of production of propionate in ruminal fluid were similar for all rations.5. The low VFA concentrations and the reduced conversion of propionate into glucose on the high rations, despite similar propionate production rates and glucose entry rates, may have been due to starch escaping ruminal fermentation. It is suggested that this glucose absorption may have reduced gluconeogenesis from propionate.
Effects of ascorbic acid on the skeletal response of chicks to vitamin D deficiency
Authors: Thornton P. A. 
Published: September 2005

1. The skeletal response of vitamin D-deficient chicks to dietary ascorbic acid was tested.2. The epiphyseal cartilaginous plate width, which was increased by the vitamin D deficiency, was further increased when ascorbic acid was added and the effect appeared sooner.3. Absence of vitamin D was associated with a reduction in the relative amount of cancellous to compact bone ash in the tibia. Dietary ascorbic acid intensified this effect to a significant degree.4. Plasma ascorbic acid levels in rachitic chicks were approximately 25% less than in controls. This observation may explain the skeletal response to added vitamin C and suggests that avian bone tissue has a particularly high requirement for this vitamin.
Effect of level of dietary calcium on the skeleton of the rat
Authors: Toothill Joyce , Hosking Zena D. 
Published: September 2005

1. The total body calcium (Expt 1) of litter-mate male rats given a diet adequate in phosphorus and high (0·74%) or low (0·13%) in Ca from the age of 3 weeks was determined after 21, 48 and 60 weeks on the diet. In Expt 2, the ash content of ten groups of bones from 10-week-old rats given these same diets for 7 weeks was studied to ascertain whether all groups were equally affected by the difference in dietary Ca level. Four groups of bones, i.e. skull and mandibles, vertebras, the shafts and the ends of long bones, were consequently chosen for examination in Expt 3 where their growth and composition were studied in rats given the Ca diets for 24, 48 or 60 weeks from the age of 3 weeks.2. Total body Ca (Expt 1), expressed as g Ca or as a percentage of the net body-weight or of net dry, fat-free carcass weight, was always significantly higher in rats given the higher level of Ca. The dietary effect was greatest after 21 weeks.3. The higher level of dietary Ca led to a highly significant increase in the weight of the dry, fat-free bone and in the percentage ash content of all ten bone groups after 7 weeks (Expt 2). The greater treatment differences in ash content occurred with the less well mineralized bones.4. In Expt 3, irrespective of diet, the four groups of bones developed at different rates. In rats given the diets for 24 weeks or longer, the vertebras and the shafts of long bones showed the greatest proportional increase in weight of dry, fat-free bone and ash relative to the corresponding values for 3-week-old rats; the greatest change in percentage ash content occurred in the ends of the long bones.5. Increasing the level of Ca in the diet increased the weight of the dry, fat-free bone and its ash content. The effect of diet decreased with increasing time on the diets, in general persisting most strongly in the skull and mandibles and declining most rapidly in the ends of the long bones. The percentage Ca and P content of the bone ash was only slightly affected by diet and, except for the Ca in the ash of vertebras, significant differences were only found in the composition of the ash of bones from 27-week-old rats.
On the postulated peroxidation of unsaturated lipids in the tissues of vitamin E-deficient rats
Authors: Bunyan J. , Green J. , Murrell Elspeth A. , Diplock A. T. , Cawthorne M. A. 
Published: September 2005

1. The micro-iodimetric method has been used to study some factors affecting the concentration of lipid peroxides in the adipose tissue of vitamin E-deficient rats.2. Cod-liver oil methyl esters (CLOME) or maize oil methyl esters (MOME) with peroxide values ranging from 3 to 330 μ-equiv./g were given by mouth to vitamin E-deficient rats deprived of food before and after the dose. Lipid peroxides did not accumulate in the adipose tissue of these rats.3. Experiments with dietary CLOME and MOME of varying peroxide values (2–230 μ-equiv./g) showed that exogenous lipid peroxide accumulates in the adipose tissue when the rats received these lipids at 10% in the diet for 4 weeks, but not if the dietary concentration was only 4% or if the diet with 10% lipid was given for 5 days only.4. Rats were given dietary CLOME for 4 weeks. Their adipose tissue was then found to contain about 50 μ-equiv. lipid peroxide/g. They were divided into three groups. One group was given a fat-free diet and, after 10 days, the adipose tissue concentration of lipid peroxide had decreased to about 10 μ-equiv./g. The other groups were given the fat-free basal diet supplemented with vitamin E or DPPD (N,N′-diphenyl-p-phenylenediamine). Neither supplement significantly affected the rate of disappearance of the peroxides from the adipose tissue.5. It was shown that neither α-tocopherol nor DPPD reacted with the lipid peroxides of CLOME or MOME in vitro, at room temperature or even after 65 h at 37°.6. It was concluded that unsaturated lipids do not become peroxidized after incorporation into the adipose tissue of vitamin E-deficient rats. Lipid peroxides taken up from the diet into the adipose tissue are not of fleeting existence, having a half-life of about 6 days. Dietary vitamin E probably prevents the accumulation of exogenous lipid peroxides in the adipose tissue by reinforcing the barrier to their absorption in the gut.7. These studies provide further evidence that current concepts of lipid peroxidation in vitamin E-deficient animals are incorrect. In fact, vitamin E-deficient animals have low concentrations of peroxide in their adipose tissue, unless they have received large amounts of unsaturated lipid for long periods, and the role of vitamin E in controlling this concentration is not due to any effect on peroxidation in vivo.
On the relationship between vitamin A and vitamin E in the rat
Authors: Cawthorne M. A. , Bunyan J. , Diplock A. T. , Murrell Elspeth A. , Green J. 
Published: September 2005

1. The effect of vitamin E on the metabolism, utilization and storage of vitamin A has been studied in the rat.2. Male weanling rats were given a vitamin A-deficient, vitamin E-deficient diet until growth had ceased for 3 days, and each rat was then given 50 i.u. vitamin A palmitate. The rats were divided into four groups and given the diet with the addition of 10% methyl oleate or 10% cod-liver oil methyl esters, or either of these diets supplemented with 100 ppm D-α-tocopheryl acetate. There was no increase in maximum weight-gain response in the two groups given vitamin E. There was a significantly lower weight-gain response in the groups given cod-liver oil methyl esters. This effect was not influenced by the presence of vitamin E in the diet.3. Weanling rats of both sexes were made deficient in vitamins A and E and then divided into two groups. One group received, every other day, 1·75 i.u. vitamin A palmitate and 0·6 mg D-α-tocopherol given together; the second group received the two vitamins, in the same amounts, on alternate days. After 28 days there was no difference in the growth of the two groups of rats, irrespective of sex.4. Vitamin A-depleted, vitamin E-deficient rats were given 17·51 μg‘14C-carbinol’retinyl acetate and then a vitamin A-deficient, vitamin E-deficient diet or that diet supplemented with 100 ppm D-α-tocopheryl acetate. After 6 days, the total remaining ‘14C’retinol and its lipidsoluble metabolites were measured in the carcasses of the rats. Vitamin E administration did not affect the metabolism of the vitamin A dose or its effect on growth.5. Vitamin E-deficient rats were given vitamin A until their liver reserves exceeded 30000 i.u. and were then divided into two groups. One group received a diet deficient in vitamins A and E and the other received, in addition to this diet, a weekly oral supplement of 1 mg D-α-tocopheryl acetate. The vitamin E supplement significantly decreased the rate of vitamin A depletion from the liver during the next 6 weeks. This effect, which was not found to occur when the initial liver reserves were only 3000 i.u., suggests a role for vitamin E in connexion with the capacity of the liver to bind vitamin A.6. The relationship between vitamin A and vitamin E in vivo cannot, in the light of these results, be regarded as that between an antioxidant and a peroxidizable substrate.
A new biological method for estimating food protein nutritive value
Authors: Mokady Shoshana , Vila S. , Zimmermann G. 
Published: September 2005

1. A new method has been devised for the nutritional evaluation of food protein quality. The method is analogous to the classical determination of net protein utilization (NPU). The suggested new criterion, the protein utilization by the liver (LPU), expresses the amount of food nitrogen ‘retained’ in the liver as a percentage of the food nitrogen intake.2. Five different foods, casein, soya-bean protein isolate, maize gluten, wheat gluten, cottonseed meal alone or with supplements of amino acids, a total of thirteen samples, were tested for LPU and NPU in groups of six rats. The correlation coefficient between values for LPU and NPU for all seventy-eight rats was +0.85 and was highly significant.
Growth inhibitory action of saccharin and cyclamate on rats receiving a poor rice diet
Authors: Sabri M. I. , Sharma S. K. , Krishna Murti C. R. 
Published: September 2005

1. The effect of saccharin and cyclamate on growth of young rats fed on a poor rice diet or a balanced diet was investigated.2. Saccharin and cyclamate retarded the growth of rats on the multi-deficient diet but not of those on the well-balanced diet during an 8-week feeding period.3. The sweeteners did not produce any macroscopic or microscopic changes in the liver, kidneys, intestines, spleen or lungs of the animals receiving the poor rice diet other than the changes resulting from the nutritional deficiency of the diet.4. The sweeteners did not inhibit the liver xanthine oxidase activity of rats receiving the poor rice diet to an extent greater than the inhibition brought about by the deficiency of protein in the diet.5. When given by intubation to healthy rats, the sweeteners inhibited the induction of liver tryptophan oxygenase; given in vitro, they inhibited the succinate dehydrogenase activity of rat liver mitochondria.