bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid metabolism in riboflavin-deficient rats
Authors: Olpin S. E. , Bates C. J. 
Published: May 2005

1. The increase in activation coefficient (stimulated: basal activity) of erythrocyte NAD(P)H2:glutathione oxidoreductase (EC16.4.2) and reduction in hepatic flavin concentration which occurred in riboflavin-deficient weanling rats were not markedly or consistently affected by differences in the concentration of lipid in the diet nor by differences in the total proportion of saturated or polyunsaturated fatty acids in the dietary lipid.2. Their gain in body-weight was, however, reduced when the dietary lipid concentration was increased from 30 to 200 g/kg and liver: body-weight and hepatic triglyceride content were correspondingly increased, suggesting a functionally-deleterious effect of high fat intake in the deficient animals. This was especially severe when the diets contained cottonseed oil, which appeared to be toxic for the deficient animals.3. Comparisons between fatty acid profiles of hepatic phospholipids of deficient, pair-fed andad lib.-fed control animals indicated that the increase in proportion of 18:2 ω6 and the decrease in proportion of 20:4 ω6 observed in deficient animals were due specifically to riboflavin deficiency, whereas certain other changes were probably caused by inanition. The changes in 18:2ω6 and 20:4 ω6 were observed at both low and high levels of lipid intake and at both low and high levels of dietary lipid polyunsaturation. Similar changes in fatty acid profiles were observed in renal, erythrocyte membrane, and plasma phospholipids, but were not seen in cardiac phospholipids.4. A consistent increase in proportion of 18:2 ω6 was also observed in the hepatic triglycerides, together with a decrease in proportion of 16:0.5. It is concluded that acute riboflavin deficiency affects lipid metabolism in a characteristic manner, probably by interfering with β-oxidation of fatty acids, but that diets of high lipid content do not significantly increase the extent of flavin depletion.
Lipid metabolism in riboflavin-deficient rats
Authors: Olpin S. E. , Bates C. J. 
Published: May 2005

1. Oxygen consumption was measured by means of an O2electrode in mitochondrial suspensions from riboflavin-deficient and pair-fed control rats, using six different substrates. Whereas consumption of O2by glutamate was only slightly depressed in mitochondria from deficient animals, the consumption of O2by hexanoate and by palmitoyl-L-carnitine was depressed to approximately half the control value: a highly significant difference. A comparable magnitude of depression was observed for stearoyl-, oleoyl-, and linoleoyl-L-carnitine. There were no major or consistent differences between groups of animals receiving two different types, and two different levels, of fat in their diet.2. The activity of acyl coenzyme A dehydrogenase (EC1.3.99.3) in hepatic mitochondrial fragments, measured by cytochromecreduction with palmitoyl-coenzyme A as substrate, and expressed as maximum velocity (Vmax) With respect to phenazine methosulphate, was also reduced to approximately half the control value in deficient animals.3. In hepatic microsomes, cytochromeb5reductase(EC1.6.2.2) activity was unaffected by riboflavin deficiency, although NADPH-cytochromecreductase (EC1.6.2.4) and microsomal flavin content were diminished to approximately half the control values. Acyl CoA (Δ9) desaturase activity (EC1.14.99.5) was virtually identical in deficient, pair-fed, andad lib.-fed control groups.4. It is concluded that the depression of mitochondrial β-oxidation of fatty acids which is observed in riboflavin-deficient animals is not a secondary result of inanition, and may account for the observed changes in fatty acid profiles of triglycerides and phospholipids. Failure of the microsomal fatty acid desaturation system is less likely to be a major consequence of riboflavin deficiency.
Response of rainbow trout (Salmo gairdneri) to increased levels of available carbohydrate in practical trout diets
Authors: Hilton J. W. , Atkinson J. L. 
Published: May 2005

1. The physiological response of rainbow trout (Salmo gairdneri) reared on different levels of available carbohydrate in practical trout diets having the same levels of energy and nitrogen for 16–24 weeks was determined.2. Weight gain was significantly reduced in trout reared on the highest level of available carbohydrate, 210 g cerelose (α-glucose)/kg, and there was a significant linear regression (R20.88) of dietary carbohydrate on weight gain.3. Liver: body-weight values and liver glycogen levels increased in relation to increased dietary carbohydrate.4. Liver glucose-6-phosphate dehydrogenase (EC1.1.1.49) activity increased and liver phosphoenolpyruvate carboxykinase (EC4.1.1.32) activity decreased per kg body-weight of fish with increasing dietary carbohydrate. However, no significant effect was noted on the activity of these liver enzymes above a dietary cerelose level of 140 g/kg.5. Liver fructose diphosphatase (EC3.1.3.11) activity increased with increasing dietary carbohydrate has been interpreted as meaning a recycling of triosephosphate to glucose-6-phosphate.6. Dietary carbohydrate level had no significant effect on the liver pyruvate kinase (EC2.7.1.40) activity, the rate of glucose utilization or the percentage conversion of [14C]alanine to glucose in the plasma of trout.7. The results indicate that rainbow trout have a limited ability to adapt to increased dietary carbohydrate and a level in excess of 140 g/kg of the diet is not efficiently utilized.
Effects of oestrogen administration on vitamin B6and tryptophan metabolism in the rat
Authors: Bender David A. , Tagoe Clemente E. , Vale Justin A. 
Published: May 2005

1.In order to assess the effects of oestrogens on the metabolism of tryptophan and vitaminB6, ovariectomized rats have been maintained on diets providing known amounts of tryptophan, nicotinamide and vitaminB6. They received oestrone sulphate. 210μg/kg body-wt per d, either incorporated in the diet for 8 weeks, or by daily intraperitoneal injection for periods of 1–3 d.2. Oestrone sulphate administration caused a slight reduction in the concentration of pyridoxal phosphate in plasma. It had no effect on the concentration of pyridoxal phosphate in liver or kidney, the urinary excretion of 4-pyridoxic acid, the activation of erythrocyte aspartate aminotransferase (L-aspartate:2-oxo-glutarate aminotransferase,EC2.6.1.1)by incubation with added pyridoxal phosphate, or the activity of pyridoxal oxidase (aldehyde:oxygen oxido-reductase,EC1.2.3.1) in the liver.3. Oestrone sulphate administration caused an increase in the urinary excretion of kynurenine and a reduction in the activity of liver kynureninase (L-kynurenine hydrolase,EC3.7.1.3), It had no effect on the urinary excretion ofN1-methyl nicotinamide or the concentrations of nicotinamide nucleotides in blood, liver or kidney.4. There was a considerable excess of the apoenzyme of kynureninase in the liver. Incubation of liver homogenates with added pyridoxal phosphate led to a 4- to 5-fold increasein activity.5. We conclude that there is no evidence of any significant effect of oestrogens on vitaminB6. It is suggested that abnormalities of tryptophan metabolism in women receiving oestrogens. which have been widely attributedto drug-induced vitaminB6depletion, can be accounted for by inhibition of kynureninase by oestrogen metabolites.
The determination of the minimal nitrogen excretion in steers and dairy cows and its physiological and practical implications
Authors: Ørskov E. R. , MacLeod N. A. 
Published: May 2005

1. Cattle were maintained by intragastric infusion to see how much nitrogen was excreted on protein-free diets.2. Minimal N excretion was estimated with two dairy cows in three periods, i.e. when they were non-pregnant and non-laclating, when they were between 117 and 133 d pregnant and when they were between 220 and 233 d pregnant. The minimal N excretion was also estimated on two occasions with two steers when their average live weights were 200 and 350 kg.3. Average urinary N excretion without protein infusion was 298, 305 and 283 mg/kg metabolic live weight (W0·75) for the non-pregnant cows and for cows during the first and second periods of pregnancy respectively; total N excretion including the faecal N was 340, 329 and 319 g/kg W0·75.4. For steers the urinary N values were 403 and 295 mg/kg W0·75at 200 and 350 kg live weight respectively and total N excretion including faecal N was 408 and 320 mg/kg W0·75.5. Urinary excretion of creatinine was the same for animals given casein via the abomasum as a source of protein or given no protein with mean values for the cows of 13·6 and 14·9 g/d for the first and second stages of pregnancy respectively. Mean values for the steers were 6·5 and 7·6 g creatinine/d at 200 and 350 kg live weight respectively.6. It is suggested that the so-called metabolic faecal N in ruminants, estimated with N-free diets, is mainly endogenous N derived from tissue breakdown of protein but incorporated in microbial debris and excreted in the faeces.
Effects of gastrointestinal cannulation and jugular vein catheterization on the metabolism of sheep
Authors: Macrae J. C. , Smith J. S. , White F. 
Published: May 2005

1. Certain digestive and metabolic criteria were examined in mature wethers before and following (1) a simple exploratory laporotomy (two sheep), (2) establishment of a rumen cannula plus simple (‘T’-shaped) cannulas in the duodenum and ileum (six sheep), (3) establishment of a rumen cannula plus two cannulas in the caecum (four sheep), (4) establishment of a rumen cannula plus re-entrant cannulus in the duodenum and ileum (four sheep) and (5) insertion of catheters into both external jugular veins (four sheep).2. Metabolizability of a standard ration and nitrogen balance and rumen retention time of the sheep were not significantly changed by any of the surgical procedures carried out.3. The amount of heat produced per unit metabolic weight of the sheep prepared with re-entrant cannulas increased significantly (21±5·6%; P < 0·001).4. The use of the different preparations in digestive and metabolic studies is discussed.
The effect of interscapular brown adipose tissue removal on body-weight and cold response in the mouse
Authors: Connolly E. , Morrisey R. D. , Carnie J. A. 
Published: May 2005

1. The removal of the interscapular brown adipose tissue (IBAT) led to an increase in body-weight of normal, lean mice as compared to anaesthetized controls.2. No significant difference in food consumption could be detected between the two groups of mice over the period of the experiment.3. Fat extraction of the whole carcasses with chloroform: methanol showed a statistically significant increase in fat content in the animals without IBAT.4. There was no apparent failure in the operated animals to sustain core temperature when exposed to a cold stress situation (4° for 24 h).5. There was no difference in the wet weight, protein content or cytochrorne oxidase content of the dorso-cervical brown adipose tissue (DCBAT) between operated and control mice. This is indicative of a lack of proliferation of other brown adipose tissue sites in the operated mice in response to the removal of the IBAT.6. It is suggested that brown adipose tissue is implicated in dietary themiogenesis in the mouse.
Lymphocyte subpopulations and antibody levels in immunized malnourished children
Authors: Salimonu L. S. , Johnson A. O. K. , Williams A. I. O. , Iyabo Adeleye G. , Osunkoya B. O. 
Published: May 2005

1. The proportions of lymphocyte subpopulations (by rosette tests) and the serum antibody levels (using haemagglutination techniques) were estimated in malnourished and well fed Nigerian children before and up to 21 d after immunization with tetanus toxoid or measles virus vaccine.2. Significantly diminished (P< 0.01) mean percentage T lymphocyte levels and considerably higher mean percentage null cell levels were observed in the malnourished children before immunization with either of the vaccines.3. There was comparable in vivo increases in percentage T lymphocytes in malnourished and control children following the administration of each antigen.4. The mean percentage B lymphocyte levels were similar in the control and malnourished children before and after the immunization.5. There was a slight depression in the tetanus antibody levels (P> 0.2) but a significant diminution (P< 0.01) in measles virus antibody concentrations in the malnourished children.6. Rise in mean percentage T lymphocytes corresponded with the elevation in mean tetanus antibody levels in both malnourished and control children following tetanus toxoid immunization. This was however not the situation in the malnourished children following immunization with measles virus.7. The observed depressed T lymphocyte number in malnourished children may in practice affect their handling of antigens such as measles virus in vivo.
The effects of the gut microflora and dietary fibre on energy utilization by the chick
Authors: Hegde S. N. , Rolls B. A. , Coates Marie E. 
Published: May 2005

1. Groups of adult colostimized chickens were given diets with and without dietary fibre in the form of bagasse or wheat straw. The fibrous materials were analysed for their contents of cellulose, hemicellulose and lignin. The digestible energies (DE) and metabolizable energies (ME) of these diets were measured by a balance method.2. Groups of germ-free and conventional chicks aged 4 weeks were given diets with and without penicillin or with and without graded levels of wheat straw as a source of fibre and the ME of these diets were determined.3. The incorporation of the forms of dietary fibre tested reduced the DE and the ME of the diets in adult conventional chickens and the ME in young germ-free and conventional chicks. Both DE and ME were reduced in proportions that suggested that the dietary fibre present was acting largely as an inactive diluent of the dietary energy and was not affecting the absorption of other nutrients. In the young germ-free and conventional chicks, there was a linear relationship between the proportion of wheat straw in one diet and the reduction in me.4. Dietary penicillin did not alter the ME of the diet in either the germ-free or the conventional environments.5. The reduction of ME with incorporation of wheat straw was less in conventional than in germ-free chicks. It is suggested that this may be due to the ability of chicks with a gut flora to obtain a small amount of energy from wheat straw.
Artificial rearing of pigs
Authors: Newport M. J. , Keal H. D. 
Published: May 2005

1. Pigs (sixteen/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/1) during a 26 d experiment. The pigs were fed on a scale based on live weight. Dried skim-milk was the only source of protein in diet U and was partially or totally replaced by a soya-bean isolate (diet B) or a concentrate (diets C and D). Soya-bean protein provided 500, 700 or 350g/kg total crude protein (nitrogen × 6·25) in diets B, C and D respectively.2. Performance was similar for diets B and D, but poorer than that of pigs given diet U. The apparent digestibility and retention of N of these diets was similar. Pigs given diet C scoured severely and twelve died.3. Protein digestion was studied in pigs given diets U, B and D, killed at 28 d of age, at the termination of the feeding experiment. The dry matter content and proportion of N in the digesta in the stomach were reduced in pigs given soya-bean protein. Pepsin concentrations in digesta and stomach tissue were unchanged.4. The concentrations of trypsin and chymotrypsin in the pancreas were greater in pigs given the soya-bean protein concentrate compared with milk protein, but only the increase in trypsin was significant (P < 0·01). Digesta from the small intestine of pigs given the soya-bean-protein isolate contained less chymotrypsin (P < 0·05). There were no differences in the proportion of non-protein-N in the total N in the digesta, suggesting that proteolysis of the milk and soya-bean proteins were equally efficient by 28 d of age.
The effects of gum arabic, wheat offal and various of its fractions on the metabolism of 14C-labelled aflatoxin B1 in the male weanling rat
Authors: Frape D. L. , Wayman B. J. , Tuck Mary G. , Jones E. 
Published: May 2005

1. Male weanling rats were given for extended periods diets containing gum arabic or wheat offal or various offal fractions. The fractions included two lipid fractions, a water-soluble extract and a modified-acid-detergent (MAD)-fibre extract. The diets contained either low concentrations of aflatoxin B1 (induced rats) or were free from this source of aflatoxin (non-induced rats). The distribution of 14C was then studied after the rats received 14C-labelled aflatoxin B1 in their feed. Blood plasma concentrations of triglycerides, and total cholesterol were also measured.2. Gum arabic and wheat offal accelerated the rate of passage of 14C through the small intestine and wheat offal very considerably decreased retention time in the large intestine. Both fibre sources increased faecal bulk. However, only wheat offal decreased liver and urinary accumulation of 14C and the effect could be explained entirely by the MAD-fibre fraction of wheat offal.3. The possible induction of either microsomal enzymes unrelated to the production of mutagenic aflatoxin metabolites, or of extramicrosomal enzymes is discussed; but it is concluded that the main effect brought about by wheat offal on the toxicity and carcinogenicity of aflatoxin can be attributed to a direct influence of the MAD fibre fraction of wheat offal on the intestinal absorption of aflatoxin B1.4. The relevance of these conclusions to drug safety studies is discussed, because comparable studies may yield differing results, despite a use of diets having the same nutrient composition but differing ingredient composition.
Glucose utilization in the horse
Authors: Ford E. J. H. , Evans Joan 
Published: May 2005

1. Total entry, irreversible loss and recycling rates of glucose were measured in four non-pregnant female Shetland ponies before and after a 24 h fast by the continuous intravenous infusion of a mixture of [U-14C] glucose and [2-3H]glucose.2. The post-fasting fall in the concentration of glucose and the rise in the concentration of ketones in plasma were not significant.3. After fasting, the total entry rate fell from 1·44±0·11 (n4) to 1·19±0·12 mg/min per kg body-weight (P> 0·01) and irreversible loss fell from 1·36±0·10 (n4) to 1·05±0·10 mg/min per kg body-weight (P> 0·02). Recycling rate did not change significantly.4. In one pony the intravenous infusion of glucose at rates of 0·52, 1·0 or 1·64 mg/min per kg body-weight had no appreciable effect on endogenous glucose production whereas in a second pony, similarly fed, total entry was depressed by 43% and irreversible loss by 54%.5. Irreversible loss of glucose in the horse is similar to that of many other species.
Patterns of electrical activity in the digestive tract of the conscious cat
Authors: Roche Maurice , Bueno Lionel , Vagne Monique , Blourde Christian 
Published: May 2005

1. Bipolar electrodes were permanently implanted on the gastric antrum, and on the different portions of the small intestine of each of eleven healthy adult cats receiving one meal daily. All parts of the feline gut exhibited, as in several other species, regular slow waves and alternate periods of quiescence and electrical spiking activity during the recording sessions lasting from 10 to 30 d.2. Patterns of electrical activity characteristic of this species were identified. Both the amplitude and frequency of the antral slow-wave were related to the presence cf superimposed spike bursts during fasting decrease in the antral slow-wave frequency and increase in the length of the duodenal plateau of slow waves after the daily meal were related to its nature.3. In fasted state, the electrical spiking activity of the small intestine occurred as fused spike bursts of large amplitude potentials migrating slowly over short distances only 24 h after feeding. They are interspersed with short periods of irregular spiking activity.4. These findings suggested that, except the distal part of the small intestine which showed an activity which resembled partially the migrating myoelectric complex observed in other species during the fasting state, the motility patterns of the digestive tract in the cat were not comparable to those observed in the dog or sheep. In the cat, mixing of the contents seemed to result from more or less regular spiking activity allowing their propulsion distally. The propagation over distances varying from 200 to 1000 mm of nine to eighteen daily fused spike bursts in the fasting state remains unclear but they are related to the digestive function in accordance with the displacement aborally of their origin in a prolonged fasting condition.
The activity of pepsin, chymotrypsin and trypsin during 24 h periods in the small intestine of growing pigs
Authors: Low A. G. 
Published: May 2005

1. Digesta were collected from twenty-two pigs, of 40 kg mean live weight, and fitted with single re-entrant cannulas in either the duodenum, jejunum or ileum.2. Three approximately isonitrogenous diets were given to the pigs; their main constituents were: barley, fine wheat offal and white fish meal (diet BWF); starch, sucrose, maize oil, cellulose and either groundnut (diet SSG) or casein (diet SSC).3. The activities of pepsin, chymotrypsin and trypsin were measured every hour in duodenal digesta during 24 h collection periods. Chymotrypsin and trypsin were also measured every hour in jejunal digesta and every 6 h in ileal digesta, during 24 h collection periods.4. The mean total pepsin activities in the duodenal digesta during 24 h collection periods (units for a 40 kg pig given 1·7 kg diet) were: 7764400 (diet BWF), 6078400 (diet SSG), 5801 600 (diet SSC).5. The mean total chymotrypsin activities (units for a 40 kg pig given 1·7 kg diet) in digesta in the duodenum, jejunum and ileum respectively were: 62920, 59560, 21 880 (diet BWF), 78240, 68400, 24680 (diet SSG). 75280, 76120, 6160 (diet SSC).6. The mean total trypsin activities (units for a 40 kg pig given 1·7 kg diet) in digesta from the duodenum, jejunum and ileum, respectively were: 256840, 362840, 77600 (diet BWF), 211 200, 205280. 46720 (diet SSG) 325720, 428560, 13600 (diet SSC).7. It was calculated that the total weights of pepsin, chymotrypsin and trypsin in duodenal digesta in 24 h periods were between 6·2 and 7·1 g. This represents 20–25% of previously published estimates of the amounts of endogenous protein in this part of the gut.