bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of early-life undernutrition in artificially reared rats: subsequent body and organ growth
Authors: Smart J. L. , Massey R. F. , Nash S. C. , Tonkiss J. 
Published: May 2005

1. Four groups of rat pups were reared: mother-reared (MR) control (well-fed) and undernourished (MRC and MRU respectively) and artificially reared (AR) control and undernourished (ARC and ARU respectively). Pups for artificial rearing were fitted with a gastric cannula on postnatal day 5 and were fed, by intermittent gastric infusion, expressed rats′ milk (days 5–7), mixtures of rats′ milk and milk-substitute (days 8–16), and milk-substitute only (days 17–20). Solid food was available to MR pups throughout and to AR pups from day 14. Undernutrition, imposed from postnatal days 5 to 25, was effected initially by underfeeding the mother (MRU) or by infusing restricted quantities of milk (ARU). Weaning was at 21 d and undernutrition from day 21 to day 25 was by restricting the supply of solid food. All rats were fedad lib.from 25 d.2. The developmental milestone, eye-opening, was delayed by undernutrition but unaffected by artificial rearing.3. Growth curves in body-weight during the refeeding phase were influenced most by previous undernutrition and to a lesser extent (also negatively) by artificial rearing.4. Fourteen measures of body and organ growth were taken at autopsy at 39 weeks. Twelve measures were affected by nutrition and only four by rearing (weight of whole body, epididymal fat pads, renal fat pads and adrenals).5. AR rats had lighter epididymal and renal fat pads than MR rats perhaps due to the low fat content of the expressed milk they received early in artificial rearing.
Involvement of the solid phase of rumen digesta in the interaction between copper, molybdenum and sulphur in sheep
Authors: Allen J. D. , Gawthornet J. M. 
Published: May 2005

1. Merino sheep fed on a diet of chopped wheaten hay, chopped lucerne (Medicago saliva) hay and oat grain were the source of rumen contents for the study. The diet contained (mg/kg dry weight) 3.3 copper, 0.24 molybdenum and 2.8 sulphur. The effects of adding between 5 and 25 mg Mo/kg as ammonium molybdate (AM) or tetrathiomolybdate (TTM) on the distribution and forms of Cu and Mo in rumen contents were investigated in vivo and in vitro.2. Approximately 88 % of the Cu and 94% of the Mo in rumen contents were associated with the solid phase. When AM or TTM was added to rumen contents in vivo or in vitro the proportion of these elements in the solid phase was increased at the expense of the fluid phase.3. The addition of AM and TTM to rumen contents also decreased the proportion of Cu that was soluble in trichloroacetic acid (50 g/l; TCA) and increased the proportion of Cu that was not extractable by sequential treatment with TCA and neutral detergent.4. Column chromatography of neutral-detergent extracts of rumen contents revealed that TTM treatment caused Cu to be strongly bound to proteins of high molecular weight.5. Addition of sulphide to rumen contents did not result in significant changes in the distribution of Cu between the fluid and solid phases, or in the solubility of Cu in TCA.6. It is postulated that constant removal of TTM from the fluid phase via reaction with proteins and other macromolecules in the solid phase results in greater formation of TTM in vivo than would be expected from solution chemistry. The molybdo-proteins so formed are strong chelators of Cu and may be the agents responsible for the decrease in Cu absorption in animals that consume diets containing high concentrations of Mo.
Effects of the amount and quality of dietary protein on nitrogen metabolism and heat production in growing pigs
Authors: Fuller M. F. , Cadenhead A. , Mollison G. , Seve B. 
Published: May 2005

1. Eight pigs with a mean weight of 48 kg were given, at a constant daily rate, diets of low (0.15) or high (0.30) protein content, very deficient in lysine, with or without a supplement of L-lysine (3.7 g/kg).2. Measurements of nitrogen and energy metabolism were made in four successive 14 d periods in a Latin-square design.3. The rate of protein accretion was substantially increased by increases in both protein and lysine supply, but the rate of heat production was not significantly changed.4. The rate of fat deposition varied inversely with the rate of protein accretion, being reduced by both protein and lysine supplements.5. The relation between heat production and protein accretion (allowing for a constant energy cost of fat deposition) suggested that heat production increased with additional protein accretion less when protein quality was improved than when more protein was given.
Effects of the amount and quality of dietary protein on nitrogen metabolism and protein turnover of pigs
Authors: Fuller M. F. , Reeds P. J. , Cadenhead A. , Seve B. , Preston T. 
Published: May 2005

1. The interrelations between protein accretion and whole-body protein turnover were studied by varying the quantity and quality of protein given to growing pigs.2. Diets with 150 or 290g lysine-deficient protein/kg were given in hourly meals, with or without lysine supplementation, to female pigs (mean weight 47 kg).3. After the animals were adapted to the diets, a constant infusion of [14C]urea was given intra-arterially for 30 h, during the last 6 h of which an infusion of [4,5-3H] leucine was also infused at a constant rate. At the same time, yeast-protein labelled with15N was given in the diet for 50 h.4. The rate of urea synthesis was estimated from the specific radioactivity (SR) of plasma urea. The rate of leucine flux was estimated from the SR of plasma leucine. The irrevocable breakdown of leucine was estimated from the3H-labelling of body water. Total N flux was estimated from the16N-labelling of urinary urea.5. Addition of lysine to the low-protein diet significantly increased N retention, with a substantial reduction in leucine breakdown, but there was no significant change in the flux of leucine or of total N.6. Increasing the quantity of the unsupplemented protein also increased N retention significantly, with concomitant increases in leucine breakdown and in the fluxes of leucine and of total N.7. It is concluded that a doubling of protein accretion brought about by the improvement of dietary protein quality is not necessarily associated with an increased rate of whole-body protein turnover.
Urea synthesis and leucine turnover in growing pigs: changes during 2 d following the addition of carbohydrate or fat to the diet
Authors: Reeds P. J. , Fuller M. F. , Cadenhead A. , Hay S. M. 
Published: May 2005

1. Studies have been made of the time-sequence of protein metabolic and hormonal changes following an abrupt increase in carbohydrate or fat intake. [3H]leucine and [14C]urea were infused for 72 h, via the aorta, into fourteen female pigs (30–38 kg body-weight). At 24 h after the start of the infusion their feed was either changed to one of two isonitrogenous diets containing additional starch (group BS, five animals) or fat (group BF, five animals), or remained unaltered (group BB, four animals). The distribution space of urea was measured by the dilution of a single dose of [14C]urea given both 48 h before and 48 h after the change in diet. The changes in the concentration and specific radioactivity of blood leucine were used to infer changes in protein turnover and those of plasma urea to measure total amino acid catabolism. The concentrations of blood glucose and plasma insulin and cortisol were also measured at approximately two-hourly intervals for the 48 h period following the change in diet.2. Within 4 h of either change in diet blood leucine concentration was lowered and the leucine specific radioactivity was raised above that in group BB, but after 24 h both the concentration and specific radioactivity of leucine returned to values similar to those in group BB. Eventually the blood leucine specific radioactivity was slightly but not significantly reduced below that of group BB.3. The addition of starch to the diet significantly reduced the synthesis and concentration of urea within 4 h but, although the addition of fat to the diet eventually lowered the urea concentration and synthesis, both changes were delayed for 18–24 h.4. In group BS plasma glucose and insulin rose after the addition of starch, but after 24–36 h both returned to values that were the same as those in the animals that received the same diet throughout (group BB). The addition of fat to the diet altered neither blood glucose nor plasma insulin concentrations. The addition of either carbohydrate or fat to the diet eventually reduced pIasma cortisol concentrations, but the change did not occur until 24 h after the change in diet.5. The results suggest that alterations in non-protein energy supply exert their immediate effect on the degradation of whole-body protein. They do not exclude the possibility that these early changes may reflect opposing changes at different sites. The results also suggest that the rate of urea synthesis may be controlled by the balance between the concentrations of insulin and cortisol, but that under the conditions of these experiments there was little relation between these hormones and the turnover of body protein as measured by the turnover of blood leucine.
Factors affecting the rate of breakdown of bacterial protein in rumen fluid
Authors: Wallace R. J. , McPherson Carol A. 
Published: May 2005

1. The cellular proteins ofButyrivibrio jibrisolvens, Lactobacillus casei, Megasphaera elsdenii, Selenomonas ruminantiumandStreptococcus boviswere labelled by growth in the presence of L-[14C]leucine, and the breakdown of labelled protein was measured in incubations of these bacteria with rumen fluid to which unlabelled 5 mM-L-leucine was added. The rate of protein breakdown was estimated from the rate of release of radioactivity into acid-soluble material.2. Protein breakdown occurred at different rates in different species. The mean rates for B.fibrisolvens, L. casei, M. elsdenii, Sel. ruminantiumandStr. boviswere 28.6, 18.1, 17.7, 10.5 and 5.3% /h respectively in samples of strained rumen fluid (SRF) with different protozoal populations. Rates of 3% /h or less were found in SRF from ciliate-free sheep or in faunated SRF from which protozoa had been removed by centrifugation. Further removal of mixed rumen bacteria had little effect. Suspensions of washed protozoa degraded bacterial protein at rates which were of the same order as those found in SRF.3. The rate of breakdown of bacterial protein in different samples of SRF tended to increase as the numbers of small entodiniomorphid protozoa increased. The numbers of larger entodiniomorphs and holotrichs had no obvious influence on this rate.4. Autoclaved and u.v.-treated bacteria were generally no different from live bacteria in their susceptibility to breakdown in SRF from faunated sheep, indicating that endogenous protein turnover was not a significant cause of bacterial protein catabolism.5. The rate of bacterial protein breakdown was unrelated to the proteolytic activity of SRF.6. It was concluded that predation by small protozoa is by far the most important cause of bacterial protein turnover in the rumen, with autolysis, other lytic factors and endogenous proteolysis being of minor importance.
Effects of infusions of lysine, leucine and ammonium chloride into the hepatic portal vein of chickens on voluntary food intake
Authors: Rusby Audrey A. , Forbes J. M. 
Published: May 2005

1. Adolescent cockerels of a laying strain were prepared with catheters whose tip lay in the hepatic portal vein, to study the effect of 3-h infusions of nutrients on food intake.2. Lysine, infused into the hepatic portal vein at rates of 150–450 mg/3 h reduced 3-h food intake by up to 58%, for a period of 6 h in previously starved birds, but had no effect on birds allowed free access to food. Infusions made into the jugular vein had no effect, suggesting a role for the liver in monitoring lysine levels.3. Portal infusion of leucine had a delayed effect while ammonium chloride, infused at isomolar rates to those of the lysine infusions, had very little effect on intake.4. The results support the concept of liver sensitivity to amino acids, but the mode of action is not clear; it appears not to be via the effects of ammonia.
Nutrient composition is a poor determinant of the glycaemic response
Authors: Sud Sudha , Sud Sudha 
Published: May 2005

1. The glycaemic response of healthy males to potato, bread, rice and green gram (Phaseoh aureus Roxb.) was compared with that to meals equivalent to these foods in terms of carbohydrate, protein, fat and fibre content, but made up of maize flour, casein, maize oil and ispaghula husk.2. Natural foods led to a higher postprandial glycaemia than their respective equivalents, but the difference was significant only in the case of potato at 0.5 h (P < 0.05).3. The insulin response, studied only in the case of rice and green gram, followed a trend similar to the glycaemic response but the differences between natural foods and equivalents were even more marked.4. A food is more than the sum of its major nutrients. Several poorly understood factors may contribute to the glycaemic response to a food. In addition to the quantity of nutrients, the response may be the result of the specific type of nutrients, non-nutrient chemicals and anti-nutrients composing the food, and their unique physical arrangement within the food.
Selenium (selenate) transport by human placental brush border membrane vesicles
Authors: Shennan D. B. 
Published: May 2005

1. Selenate uptake by human placental brush-border-membrane vesicles was studied in order to establish whether this anion shares a pathway with sulphate.2. Selenate uptake was found to be saturable with respect to medium selenate and was inhibited by the anion exchange inhibitor 4,4′-diisothiocyano-stilbene-2,2′-disulphonate (DIDS).3. Anions which have a similar tetrahedral shape to selenate, e.g. chromate, molybdate, tungstate and sulphate, were effective inhibitors of selenate uptake when added to the incubation medium.4. Sulphate inhibited selenate influx in a dose-dependent fashion; moreover sulphate was found to be a competitive inhibitor of selenate uptake.5. It is concluded that selenate and sulphate share a pathway for transport in the human placental microvillus membrane.
A viscous fibre (methylcellulose) lowers blood glucose and plasma triacylglycerols and increases liver glycogen independently of volatile fatty acid production in the rat
Authors: Topping David L. , Oakenfull David , Trimble Rodney P. , Illman Richard J. 
Published: May 2005

1. Adult male rats were maintained on diets containing 80 g methylcellulose/kg of low (25 cP), medium (400 cP) and high (1500 cP) viscosity.2. After 10 d, the viscosity of stomach and caecal contents was found to have increased in proportion to that of the dietary fibre. Concentrations of volatile fatty acids in caecal digesta were lowest with the high-viscosity fibre but acetate was the major acid present with all three diets. Acetate was the only acid found in significant quantities in hepatic portal venous plasma and concentrations of this acid were unaffected by diet.3. Concentrations of glucose in arterial blood were low with the medium-and high-viscosity diets while the content of liver glycogen was high. These effects of fibre were not directly on glucose absorption as the intestines were net removers of the hexose at the time of sampling.4. Hepatic lipogenesis and plasma triacylglycerol concentrations were both higher in rats fed on the low-viscosity fibre. Plasma cholesterol concentrations, hepatic cholesterol synthesis and faecal bile acid excretion were not altered by dietary fibre viscosity.5. We conclude that the effects of dietary fibre on carbohydrate absorption and storage and fatty acid synthesis are a function of the viscosity of the fibre in solution, high viscosity slowing the digestion and absorption of nutrients in the small intestine. Large-bowel microbial fermentation is not of direct significance to these events. In contrast, effects of fibre polysaccharides on sterol metabolism seem not to be related to their rheological properties.
Effect of cooking, pH and polyphenol level on carbohydrate composition and nutritional quality of a sorghum (Sorghum bicolor (L.) Moench) food, ugali
Authors: Knudsen K. E. Bach , Munck L. , Eggum B. O. 
Published: May 2005

1. The present work was undertaken to study the effects of cooking, pH and polyphenol level on carbohydrate composition and nutritional quality of sorghum (Sorghum bicolor (L.) Moench). Three different sorghum varieties; Dabar, Feterita and Argentine containing zero, intermediate to low and high levels of polyphenols respectively were used in the study. From these varieties uncooked, uncooked acidified, cooked, and cooked acidified diets were prepared. Diets were characterized with regard to resistant starch (RS), dietary fibre (DF), acid-detergent fibre (ADF) and amino acid content. Raw materials were further analysed for content and composition of non-starch polysaccharides and Klason lignin. The nutritional properties were studied in balance trials with rats. True protein digestibility (TD), biological value (BV), net protein utilization, digestible amino acids, digestible energy (DE) and digestible DF were used as criteria in the nutritional study.2. Cooking at neutral and acid pH resulted in significantly higher assayed values for DF. Increase in DF could be accounted for by formation of RS. Approximately 50% of RS was recovered in the faeces.3. In vitro values for protein associated with ADF and in vivo balance values using rats suggest that an endosperm protein fraction, kafirins, was made unavailable during cooking. This resulted in reduced TD and increased BV. It is assumed that unavailable kafirins serve as a nitrogen source for microflora in the hind-gut.4. Dietary polyphenols changed the excretory route for N from urine to faeces. This resulted in lower TD and higher BV in Argentine (high in polyphenols) than in Dabar and Feterita (low in polyphenols), although dietary lysine (first limiting amino acid) was the same in the three varieties.5. Variation in DE of the diets was attributed to DF, RS and the amount of faecal protein, which in turn were influenced by undigested kafirins and polyphenols.
The effect of Gypsophila saponins in the diet on mineral status and plasma cholesterol concentration in the rat
Authors: Southon Susan , Johnson I. T. , Gee Jennifer M. , Price K. R. 
Published: May 2005

1. Immature, male Wistar rats were allocated to one of six groups and caged individually. The first group was given a semi-synthetic diet containing 38 mg iron and 55 mg zinc/kg (basal group). The second and third groups were given a diet containing 10 mg Zn and 12 mg Fe/kg respectively (low-Zn and low-Fe groups). Groups four, five and six were given similar diets containing 20 gGypsophilasaponins/kg. After 21 d the Fe and Zn status of the rats was estimated and plasma cholesterol concentration determined.2. Measurements of whole blood haemoglobin concentration, packed cell volume and liver Fe stores indicated that rats in the basal + saponin and low-Fe + saponin groups had a significantly reduced Fe status when compared with their controls. Rats in the low-Zn + saponin group also showed a trend toward reduced Fe stores.3. Zn status, as judged by femur Zn concentration, was not adversely affected by the inclusion ofGypsophilasaponins in the diet.4. Consumption of the saponins resulted in a significant reduction in blood cholesterol concentration, with rats in both the low-Fe groups having significantly lower concentrations than their basal and low-Zn counterparts.5. In view of suggestions that the consumption of saponins should be encouraged because of their ability to lower blood cholesterol, possible effects on Fe metabolism should be investigated further, particularly with respect to the levels and sources of saponin in the human diet.
Factors affecting the voluntary intake of food by sheep
Authors: Grovum W. L. , Chapman H. W. 
Published: May 2005

1. Sheep with oesophageal fistulas were sham-fed on pelleted lucerne (Medicago sativa) hay to assess the palatability of added chemicals representing the tastes of sweet (sucrose), sour (hydrochloric acid), salt (sodium chloride), bitter (urea) and umami (monosodium glutamate; MSG).2. Plain pellets and four concentrations of each chemical were sham-fed for 30 min after 5·5 h deprivation in 5x5 Latin-square experiments following a period of adaptation feeding.3. Sucrose, at concentrations of 15–120 g/kg air-dried pellets, depressed intakes with a linear relation between intake (I; g) and concentration (C; g/kg): I = 1001-3·42C.4. HCl at 6·25–25·0 g/kg pellets had no effect on sham intakes but at 50 g/kg reduced them by 50% of control (P < 0·05).5. NaCl at 50–200 g/kg increased sham intakes by 26% (P < 0·01) with no evidence of a dose-related effect.6. Urea at 10–80 g/kg decreased sham intakes by 26·9% (P < 0·01) with no evidence of a dose-related effect.7. MSG at 5–40 g/kg in two experiments increased sham intakes by 16·1 and 40·8% (P < 0·05). In another experiment at 1-8 g/kg there wasno significant effect.8. When palatability and post-ingestive effects are separated by sham-feeding, the effect of added chemicals on intake may be completely different from when they are ingestednormally (e.g. NaCl and sucrose). This newly developed technique enables the palatabilityeffect of feed additives to be tested critically and economically.
Messenger RNA levels of plasma proteins following fasting
Authors: De Jong Felice A. , Howlett Geoffrey J. , Schreiber Gerhard 
Published: May 2005

1. The effect of fasting on hepatic mRNA levels of seven plasma proteins was examined in the rat.2. The levels of mRNA were measured directly in cytoplasmic extracts by hybridization to specific32P-labelled cDNA probes.3. Following a 48 h period of fasting, the mRNA levels of apolipoprotein E, apolipoprotein A-IV, albumin, transferrin, and transthyretin decreased by 15–30%, while apolipoprotein A-II decreased by 78% compared with non-fasted control rats. The mRNA for apolipoprotein A-I increased by 33%.4. These findings suggest that mRNA levels in the liver following fasting are regulated independently and variations in these levels may be due to differences in transcription rates or mRNA stability.
Influence of lactose on phosphate metabolism in rats
Authors: Dębiec Hanna , Lorenc Roman 
Published: May 2005

1. Lactose, sucrose or maltose were administered to rats by gavage together with32PO4, and blood32P was determined.2. PO4uptake into blood was increased only when lactose and PO4were administered into the gut.3. Weaned male rats were fed on a control diet or a diet containing 30, 60 or 120 g lactose/kg. After a 5 d period of adaptation, a 6 d P balance was carried out. After a further 24 d blood levels of PO4, and calcium and PO4uptake by brush-border membrane vesicles prepared from the renal cortex, were determined.4. The absorption and retention of P were higher in lactose-fed rats. Faecal P excretion decreased with increasing dietary lactose content. Urinary P excretion was lower in the rats fed on 30 and 60 g lactose/kg whereas the 120 g lactose/kg diet increased urinary P.5. Membrane vesicles isolated from rats fed on the diets containing 30 and 60 g lactose/kg showed a higher uptake of PO4, but with the 120 g lactose/kg diet uptake was lower than with membrane vesicles isolated from rats fed on the control diet.6. A statistically significant increase in the serum PO4level was observed in the rats fed on the diet with 120 g lactose/kg.7. The presence of lactose in the diet caused a stirnulatory effect on PO4absorption and retention.