bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of whole-body protein synthesis to basal metabolism in layer and broiler chickens
Authors: Muramatsu T. , Aoyagi Y. , Okumura J. , Tasaki I.
Published: September 2005

1. The effect of starvation on whole-body protein synthesis and on the contribution of protein synthesis to basal metabolic rate was investigated in young chickens (Expt 1). Strain differences between layer and broiler chickens in whole-body protein synthesis and degradation rates were examined when the birds were starved (Expt 2).

2. In Expt 1, 15-d-old White Leghorn male chickens were used, while in Expt 2 Hubbard (broiler) and White Leghorn (layer) male chickens at 14 d of age were used. They were starved for 4 d, and heat production was determined by carcass analysis after 2 and 4 d of starvation. Whole-body protein synthesis rates were measured on 0, 2 and 4 d of starvation (Expt 1), and on 0 and 4 d of starvation (Expt 2).

3. The results showed that starving reduced whole-body protein synthesis in terms of fractional synthesis rate and the amount synthesized. Whole-body protein degradation was increased by starvation both in terms of fractional synthesis rate and the amount degraded on a per kg body-weight basis.

4. Reduced fractional synthesis rate of protein in the whole body was accounted for by reductions in both protein synthesis per unit RNA and RNA:protein ratio.

5. In the fed state, whole-body protein synthesis and degradation rates, whether expressed as fractional rates or amounts per unit body-weight, tended to be higher in layer than in broiler chickens. In the starved state, the difference in the rate of protein synthesis between the two strains virtually disappeared, while the degradation rates were higher in layer than in broiler birds.

6. Based on the assumed value of 3.56 kJ/g protein synthesized (Waterlow et al. 1978), the heat associated with whole-body protein synthesis in the starved state was calculated to range from 14 to 17% of the basal metabolic rate with no strain difference between layer and broiler chickens.
Effect of different levels of phosphorus on rumen microbial fermentation and synthesis determined using a continuous culture technique
Authors: Komisarczuk Sylvie , Merry R. J. , McAllan A. B.
Published: September 2005

1. A continuous culture technique was used to study the phosphorus requirements of rumen micro-organisms. Solutions of artificial saliva containing 120, 80, 40 and 0 mg inorganic phosphorus (Pi)/1 were infused into the reaction vessels previously inoculated with rumen contents, resulting in Piconcentrations in the vessel contents of 48, 28, 4 and < 1 mg/l respectively. Various fermentative and synthetic characteristics were examined.

2. In the vessel contents, concentrations of protozoa (about 0.9 x 105/ml) were not significantly affected by piconcentration. Total volatile fatty acids (VFA) produced averaged about 6.83 mmol/h with Pilevels of 48 and 28 mg/l. Reduction in Piconcentrations to 4 and < 1 mg/l resulted in significant reductions in total VFA to approximately 6.25 and 3.75 mmol/h respectively, accompanied by a rise in pH from 6.5 to 7.3. Ammonia-nitrogen values, which averaged about 131 mg/l at the higher Piconcentrations, also increased with the lowest level of Pito about 240 mg/l. ATP concentrations averaged about 14 μmol/l at the highest Piconcentration and fell progressively with each reduction in Piconcentration to a final value of 2.5μmol/1 with the Pilevel < 1 mg/1.

3. At Piconcentrations of 48 and 28 mg/l, the digestibilities of xylose, arabinose and cellulose-glucose were maintained at about 0.90, 0.62 and 0.70 g/g input respectively. At lower Pi, concentrations these digestibilities fell significantly and corresponding values at Pi< 1 mg/l were 0.73, 0.41 and 0.31 respectively. Starch digestion was unaffected by Piconcentrations and remained at about 0.90 g/g input.

4. The amount of microbial-N synthesized averaged 0.48 g/d and was maintained with Piconcentrations down to 4 mg/l. There was, however, a significant reduction to 0.26 g/d with Piconcentrations of < l mg/l. The effiency of microbial protein synthesis was variable but averaged approximately 25 g N/kg total carbothdrate fermented.

5. It was estimated that the minimum Piconcentrations required in rumen fluid in vivo to maintain maximum degradative and synthetic microbial activities was in the range 75–100 mg/l and that the over-all P requirement of the microbes was of the order of 5.1 g/kg apparently digested organic matter intake.
Decrease in amylase (EC3.4.21.4) synthesis in lactating rats
Authors: Mizoguchi Junji , Imamichi Tomonori
Published: September 2005

1. The amylase (EC3.4.21.4) and trypsin (EC3.2.1.1) activities in the pancreas in rats during pregnancy, lactation and after the weaning period, and the secretory responses to a secretagogue (caerulein) in the exocrine pancreas of lactating rats were measured.

2. Trypsin activity increased as lactation progressed and reached twice that of unmated rats in the second half of the lactation period. The amylase activity fell before parturition and failed to recover even after the start of lactation and was significantly decreased throughout the lactation period.

3. The total amount of pancreatic juice produced in the lactating rats was significantly greater than that of unmated rats; the amylase output was significantly less than that of unmated rats.

4. When the pups were removed, amylase activity in the pancreas returned to the value in unmated rats. Furthermore, the amylase activity in lactating rats receiving a daily injection of insulin significantly exceeded that of normal lactating rats.

5 These results indicate that the decrease in amylase activity in lactating rats is due to the reduction of amylase synthesis and there is a possibility that insulin is required for normal or elevated rates of amylase synthesis in lactating rats.
Relative nutritional availability to rats of selenium in Finnish spring wheat (Triticum aestivum L.) fertilized or sprayed with sodium selenate and in an American winter bread wheat naturally high in Se
Authors: Mutanen Marja , Koivistoinen Pekka , Morris Virginia C. , Levander Orville A.
Published: September 2005

1. A Finnish national programme to fertilize crops with sodium selenate led us to compare the nutritional availability to rats of selenium in two Finnish spring wheats (Triticum aestivum L.), either fertilized or sprayed with sodium selenate, with that in an American winter bread wheat naturally high in Se.

2. Weanling male rats were given a Se-deficient Torula yeast diet for 4 weeks followed by either continued depletion or repletion for 4 weeks with graded levels of Se as sodium selenite (standard) or wheat (test food). Plasma and liver Se levels and plasma and liver glutathione peroxidase (EC 1.11.1.9; GSH-Px) activities were used as criteria of body Se status.

3. The availability of Se under these conditions was calculated with the point-slope technique at two dietary levels of Se (Expt 1) and with the slope-ratio method (Expt 2).

4. In the point-slope assay, the level of dietary Se fed had a considerable effect on the apparent availability values obtained which made interpretation of the results difficult. In the slope-ratio assay, no difference in the availability of Se from the various wheats was observed when plasma or liver Se levels were used as the response criteria.

5. The Se in the fertilized wheat was somewhat more available than that in the sprayed wheat when plasma or liver GSH-Px activities were the response criteria. Overall, availability values (% ) derived by averaging all four response criteria were 86, 77 and 73 for the fertilized and sprayed Finnish wheats and the American wheat respectively (sodium selenite 100).

6. These results show that wheat is a relatively available source of Se to rats regardless of whether its Se content is naturally high or is increased by fertilization or spraying.
Factors influencing the absorption of iron from soya-bean protein products
Authors: Derman D. P. , Ballot D. , Bothwell T. H. , Macfarlane B. J. , Baynes R. D. , Macphail A. P. , Gillooly M. , Bothwell J. E. , Bezwoda W. R. , Mayet F.
Published: September 2005

1. The absorption of iron from soya-bean (Glycine hispida)-based and milk-based infant formulas was assessed in 138 multiparous Indian women, using the erythrocyte utilization of radioactive Fe method.

2. Fe absorption was significantly greater from the basal milk formula (1.5 g protein) than it was from the basal soya-bean formula (2.3 g protein), with geometric mean values of 0.083 and 0.044 respectively.

3. Ascorbic acid markedly increased Fe absorption from the milk-based formula in a dose-dependent fashion. The increase was fivefold when the ascorbic acid: Fe ratio on a weight-for-weight basis was 6: 1 and over tenfold when it was 20:1. In contrast, ascorbic acid had a less-marked effect on the absorption of Fe from the soya-bean-based formula, with only a two- to threefold increase at an ascorbic acid: Fe ratio of 20: 1.

4. The geometric mean Fe absorption from the soya-bean formula (1.27 mg Fe, 2.3 g isolated soya-bean protein (ISP)) was somewhat less than that from the same amounts of ISP and ascorbic acid made up in milk (0.075 and 0.1 13 respectively). However, a direct comparison between the soya-bean formula in milk and in water showed no significant difference (0.043 and 0.060 respectively).

5. Fe absorption from a drink containing 10 g ISP and 30 mg ascorbic acid was significantly better than that from a similar drink containing the soya-bean flour from which ISP is extracted (0.044 and 0.027 respectively).

6. Heating ISP to 200° for 2 h before its use had no effect on Fe availability. When 2.3 g heated ISP (10 mg ascorbic acid) was compared with a similar formulation of untreated ISP, Fe absorption values were 0.135 and 0.099 respectively. Comparable values with 25 g ISP (no ascorbic acid) were 0.067 and 0.058.

7. Citric acid in amounts of 1 4 g had a dose related but limited enhancing effect on Fe absorption from 10 g ISP, with a rise from 0.01 1 (no citric acid) to 0.068 (4 g citric acid).

8. There was appreciable variability in the levels of Fe absorption in different studies, which suggested that unidentified manufacturing or preparative differences might be influencing the overall results.
Detraining of exercise-trained rats: effects on energetic efficiency and brown adipose tissue thermogenesis
Authors: Arnold Jeff , Richard Denis
Published: September 2005

1. Complete energy balance measurements were made in exercise-trained (treadmill running) rats subjected to 27 d of exercise detraining.

2. The 20% difference in body-weight that existed at the end of the training period between sedentary and trained rats was negated by detraining. Detrained rats had twice the body-weight gain of their untrained controls.

3. An elevation (12%) in metabolizable energy (ME) intake (relative to body-weight) was observed in detrained rats while their gross energetic efficiency was augmented by 60%.

4. Energy expenditure, excluding the estimated costs of fat and protein storage, was similar for detrained and untrained rats. Complementing the latter was the finding that thermogenesis in brown adipose tissue, a known energy buffering process, was also similar.

5. Elevated ME intake (relative to body-weight) largely contributed to the increased energetic efficiency of detrained rats.
Differential oxidation of saturated and unsaturated fatty acids in vivo in the rat
Authors: Leyton J. , Drury P. J. , Crawford M. A.
Published: September 2005

1. The oxidation rates of lauric, myristic, palmitic, stearic, oleic, α-linolenic, linoleic, γ-linolenic, dihomo- γ-linolenic and arachidonic acids were studied by use of a radioisotope tracer technique in weanling rats at rest in a metabolism chamber over 24 h.

2. Of the saturated fatty acids, lauric acid (12:O) was the most efficient energy substrate: the longer the chain length of the saturated fatty acids, the slower the rate of oxidation.

3. Oleic acid (18:1) was oxidized at a remarkably fast rate, similar to that of lauric acid.

4. Of the ω6 essential fatty acids studied, linoleic acid (18:2ω6) was oxidized at a faster rate than any of its metabolites, with arachidonic acid (20:4ω6) being oxidized at the slowest rate.

5. The rate of oxidation of γ-linolenic acid (18:3ω3) was almost as fast as that of lauric and oleic acids.
Effect of food intake on protein and energy metabolism in finishing beef steers
Authors: Lobley G. E. , Connell Alexmary , Buchan Vivien
Published: September 2005

1. The effects of progressive reduction in food intake from 1.6 x maintenance (1.6 M) to approximately maintenance (M′) and then to zero (fasting) on energy expenditure and leucine kinetics were examined in Hereford x Friesian finishing beef steers.

2. Estimates of whole body protein synthesis and protein oxidation were obtained from the specific radioactivity of free leucine in blood and of exhaled carbon dioxide during continuous infusions of [I-14C]leucine. Protein synthesis contributed a minimum of 0.19 to total heat production across all three intakes.

3. The apparent efficiencies with which synthesized protein was retained were 0.28 between 1.6 M and M′ and 1.04 between M′ and fasting. The greater efficiency below M′ reflected probable use of amino acids as energy sources during fasting, which would be spared as soon as feed was available.

4. Nitrogen derived from protein oxidation made a minor contribution to urine N at both 1.6 M (0.45) and M′ (0.36) but provided a significant proportion to the increment in urine N between intakes (0.68).

5. Amino acid absorption, estimated indirectly as the sum of protein oxidation and protein retention, represented only 0.28 of N intake at M′ and 0.38 at 1.6 M but the contribution to the increment in N intake between these two diet levels was greater (0.56).

6. The estimated efficiency of utilization of absorbed amino acids between M′ and 1.6 M was 0.45.
The retention and metabolism of Nτ-methylhistidine by cockerels: implications for the measurement of muscle protein breakdown determined from the excretion of Nτmethylhistidine in excreta
Authors: Harris C. I. , Milne G. , McDiarmid Ruth
Published: September 2005

1. Excreta were collected for four consecutive days from 4- to 18-week-old cockerels following subcutaneous injection of Nτ-[14CH3]methylhistidine.

2. The recoveries of radioactivity in excreta were incomplete and progressively decreased with increasing age.

3. Most of the radioactivity not recovered in excreta after 4 d was found in skeletal muscle where > 55% of the radioactivity present was in the Nτ-methylhistidine-containing dipeptide, balenine.

4. This peptide appeared to be relatively stable so that most of the labelled Nτ-methylhistidine incorporated was not released during the period of the recovery measurements.

5. The total pool of non-protein bound Nτ-methylhistidine (free Nτ-methylhistidine+balenine) in pectoral and mixed thigh muscles increased with age and relative to the daily excretion of Nτ-methylhistidine. At 18 weeks the pool was 3.3 times the daily excretion of Nτ-methylhistidine.

6. These observations account for the decreasing recoveries of radioactivity in excreta described previously, due to progressive dilution of labelled Nτ-methylhistidine in an expanding pool of non-protein-bound Nτ-methylhistidine, part of which was relatively stable.

7. It is concluded that excretion of Nτ-methylhistidine by 4- to 18-week-old cockerels cannot be used as a reliable index of muscle protein breakdown in vivo.
Diet composition and lipoprotein lipase (EC3.1.1.34) activity in human obesity
Authors: Smolin Lori A. , Grosvenor Mary B. , Handelsman David J. , Brasel Jo Anne
Published: September 2005

1. Adipose tissue lipoprotein lipase (EC3.1.1.34; AT-LPL), a rate-limiting enzyme in triglyceride storage in adipose tissue, is hormonally regulated and may be important in the maintenance of obesity.

2. In twelve obese women, AT-LPL activity was measured before weight loss, during weight loss and after 1 and 2 weeks of weight maintenance on either a high-carbohydrate or a high-protein diet.

3. When related to tissue weight, AT-LPL activity during the 2 weeks of weight maintenance was higher than the initial AT-LPL activity; there was no difference when activity was expressed per cell.

4. Changes in AT-LPL activity were not affected by diet composition. AT-LPL activity correlated with insulin levels and a change in the insulin sensitivity of AT-LPL was observed after weight loss.
Contribution of cowpea (Vigna unguiculata) in a mixed diet to the nutrient intake of rural children in Ibadan
Authors: Akinyele I. O. , Akinlosotu A.
Published: September 2005

1. Sixty-four subjects from the rural areas of Ibadan participated in a study to determine the contribution of cowpea (Vigna unguiculata) foods to the total intake of nutrients in a mixed diet. The subjects were randomly selected from those who, according to their mothers, reacted to cowpea foods (reactors) and those who did not (non-reactors).

2. The results showed that for all subjects, protein, energy and riboflavin needs were not met from the total diet consumed. However, the requirements for vitamin A, thiamin and iron were met.

3. Between 30 months and 3 years of age, cowpeas contributed 36.2 and 30.3 % of protein intake for nonreactors and reactors respectively. Corresponding values for energy intake were 17.3 and 17.2 % respectively. Lower percentages were contributed by the diets of 4- to 6-year-olds.

4. Irrespective of the classification system used, some of the subjects were found to be suffering from mild to moderate malnutrition, with a few severe cases.
Effects of fasting in Ramadan on Tropical Asiatic Moslems
Authors: Husain R. , Duncan M. T. , Cheah S. H. , Ch'ng S. L.
Published: September 2005

1. Anthropometric variables, resting heart rate and respiratory gas exchange were measured in twelve male and nine female Asiatic adult Moslems during the month of Ramadan, the week before and the month after Ramadan.

2. Energy intakes were estimated from dietary recall during fasting and non-fasting conditions.

3. Both male and female subjects experienced a decrease in body mass with the reduction in energy intake during fasting. Males experienced a greater reduction than females in resting heart rate; females lost more body weight and subcutaneous fat than males.

4. Urine output and fluid intake were measured in twelve male subjects for 1 d during each week of fasting and 1 d during the pre-fasting control period. Among the subjects examined, the Ramadan regimen did not result in changes in the pattern of fluid exchange.
Microbial protein and peptide metabolism in rumen fluid from faunated and ciliate-free sheep
Authors: Wallace R. J. , Broderick G. A. , Brammall Margaret L.
Published: September 2005

1. Protease and deaminase activities and the metabolism of peptides were measured in rumen fluid from ciliate- free sheep and from sheep with a limited population of small entodinia. The same measurements were repeated following inoculation of the latter group with a more typical mixed ciliate population.

2. Protease and dialanine uptake activities of mixed rumen micro-organisms were not significantly influenced by protozoa. Trialanine uptake, leucine aminopeptidase (EC 3.4.11. 1), deaminase and trypsin-like protease activities were 70, 107,73 and 91 % higher with the limited population, and 72,58,64 and 55 % higher when mixed protozoa were present, indicating a major role for the protozoa in these activities.
Stimulatory effect of short-chain fatty acids on epithelial cell proliferation in the rat intestine: a possible explanation for trophic effects of fermentable fibre, gut microbes and luminal trophic factors
Authors: Sakata Takashi
Published: September 2005

1. Effects of short-chain fatty acids (SCFA) on epithelial proliferation of the intestine were studied in ileally fistulated rats fed on an elemental diet.

2. The stimulatory effect of daily doses of acetic, propionic and n-butyric acids (100,20 and 60 mM respectively; pH 6.1) per fistula (3 ml, twice daily) on crypt cell production rate (CCPR) appeared within 2 d and lasted for at least 5 d.

3. The daily doses of SCFA for 14 d increased daily CCPR three to four fold. This effect was independent of the presence of gut bacteria.

4. Effects of SCFA were dose-dependent and varied among acids (butyrate > propionate > acetate). The effect was independent of low lumen pH.

5. In contrast, SCFA inhibited epithelial proliferation of isolated rat caecal tissue in vitro.

6. These results suggest that SCFA are physiological lumen trophic factors mediated by a systemic mechanism in vivo.

7. It is concluded that SCFA are involved in the trophic effects of gut microbes, ingestion of fermentable fibre, and lumen contents.
Vitamin E kinetics in sheep
Authors: Hidiroglou M. , Karpinski K.
Published: September 2005

1. Kinetics of physiological doses of D-α-[5-Me-3H]tocopherol(200 μCi) administered to twenty-four sheep were studied using one of four routes: intravenous, oral (capsules), intraruminal and intramuscular.

2. Blood samples were withdrawn from the jugular vein periodically for 96 h after the intravenous and oral administrations, for 168 h after the intraruminal administration and for 216 h after the intramuscular administration.

3. The study indicated that the biological availability of α-tocopherol followed the order intravenous > intramuscular > oral > intraruminal.

4. The rate of elimination was in the order intravenous > oral > intraruminal ˜ intramuscular.

5. The intravenous route was fitted with a three-compartment model, whereas the other routes exhibited a good fit for either a one- or two-compartment model.
Identification of thiomolybdates in digesta and plasma from sheep after administration of 99Mo-labelled compounds into the rumen
Authors: Price J. , Will A. Marie , Paschaleris G. , Chesters J. K.
Published: September 2005

1. At 16 h after the rapid injection of 99Mo-labelled compounds into the rumen of sheep maintained on dried grass (6.2 mg molybdenum/kg dry matter (DM), 4.3 g sulphur/kg DM), labelled thiomolybdates associated with the digesta solids or bound to plasma macromolecular species were displaced from their carriers in vitro and identified by Sephadex G25 chromatography.

2. After molybdate injection, the thiomolybdates displaced from rumen, duodenal and ileal solids were predominantly the trithio- and tetrathio- species. Dithiomolybdate was present to a relatively minor extent. Trace amounts of di- and trithiomolybdates were detected in the liquid phase of digesta from the duodenum.

3. Whether injected into the rumen as molybdate or tetrathiomolybdate, bound 99Mo appearing in plasma was present mainly as di- and trithio- species. The tetrathio- species appeared in trace amounts in plasma only after tetrathiomolybdate injection, despite its existence almost exclusively in this form in rumen digesta.

4. The present study provides direct evidence for thiomolybdate synthesis within the rumen and indicates that while the effects of thiomolybdates in inhibiting copper absorption are likely to be due to tri- and tetrathio- molybdates, post-absorptive effects on Cu metabolism are probably due to di- or trithiomolybdate.
Effects on plasma insulin of intermittent infusions of propionic acid, glucose or casein into the alimentary tract of non-lactating cows maintained on a liquid diet
Authors: Istasse L. , Macleod N. A. , Goodall E. D. , Ørskov E. R.
Published: September 2005

1. An experiment was conducted using three non-lactating cows completely maintained by infusions of volatile fatty acids into the rumen, and casein into the abomasum. Plasma insulin responses to propionic acid, glucose or casein were recorded. Further information was obtained using protein-free infusions.

2. When part of the propionic acid was infused into the rumen in a twice-daily 3 h dose and the remainder infused continuously with acetic and butyric acids and casein, there were large increases in the concentrations of propionic acid and insulin in the jugular blood. When glucose, corresponding in energy to that supplied by the intermittent propionic acid infusions was similarly infused, the plasma levels of glucose and insulin were increased. Glucose appeared to stimulate a greater increase in insulin than did propionic acid. Casein infused into the abomasum in intermittent doses produced a rise in plasma insulin, but smaller than that observed with propionic acid or with glucose.

3. The protein-free infusion was characterized by a lower concentration of insulin in the blood plasma, a reduction in plasma urea and free amino nitrogen and unchanged plasma glucose.
Energy intake, expenditure and pattern of daily activity of Nigerian male students
Authors: Cole A. H. , Ogbe J. O.
Published: September 2005

1. Twenty apparently healthy and normal Nigerian male students, resident at the University of Ibadan campus, were studied for seven consecutive days to assess their food energy intake and expenditure and pattern of their daily activities.

2. The mean age (years) of the group was 24.0 (SD 3.23, range 20–30), mean height (m) 1.71 (SD 0.06, range 1.61–1.84) and body-weight (kg) was 61.1 (SD 5.01, range 51.0–69.5).

3. The food intake of each subject was obtained by direct weighing and its energy value determined using a ballistic bomb calorimeter. Patterns of daily activities were recorded and the energy costs of representative activities were determined by indirect calorimetry.

4. Activities mainly involved sitting, mean 580 (SD 167, range 394–732) min/d. Sleeping and standing activities took a mean of 445 (SD 112) and 115 (SD 75) min/d respectively. Personal domestic activities took a mean of 94 (SD 40) min/d.

5. The mean energy intake of the group was 11 182 (SD 1970) kJ/d or 183 (SD 32) kJ/kg body-weight per d. This value is lower than the 12.5 MJ/d recommended by the Food and Agriculture Organization (FAO)/World Health Organization (WHO) (1973) as the energy requirement for an adult man engaged in moderate activities, but it is higher than the FAO/WHO/United Nations University (UNU) (1985) recommended value of 10.8 MJ/d for a male office clerk (light activity). It is also lower than the recommended energy requirement of 11.6 MJ/d for a subsistence farmer (moderately active work) (FAO/WHO/UNU, 1985).

6. The mean energy expenditure of the male subjects was 9876 (SD 1064, range 7159–12259) kJ/d and was lower than mean intake.

7. The energy intake and expenditure values indicated that the groups participating in the present study were not physically very active. It is an indication that the Nigerian male students expended less but probably consumed more energy than required. It is suggested for health reasons and for mental fitness that the Nigerian male students might undertake more physical exercise.
Effect of pectin, wheat bran and cellulose on serum lipids and lipoproteins in rats fed on a low- or high-fat diet
Authors: Vigne Jean Louis , Lairon Denis , Borel Patrick , Portugal Henri , Pauli Anne-Marie , Hauton Jacques Christian , Lafont Huguette
Published: September 2005

1. Four groups of adult male Sprague–Dawley rats were fed for 6 weeks on a diet with a low-fat content (50 g/kg) and another four groups were given a diet rich in fat (250 g/kg) and cholesterol (12 g/kg). In both cases, the basal diets were either fibre-depleted or supplemented with cellulose (60 g/kg), wheat bran (100 g/kg) or low-methoxyl pectin (100 g/kg).

2. Low-methoxyl pectin displayed the most hypocholesterolaemic effect and decreased the cholesterol content of the very-low-density lipoproteins (VLDL) and low-density lipoproteins (LDL), when the low-fat diet was given. When rats were fed on the high-fat diet, pectin no longer had a hypocholesterolaemic effect but still decreased the VLDL-cholesterol content. Pectin lowered serum triglyceride and VLDL-trigylceride levels only when the low-fat diet was given.

3. Wheat bran exerted no hypocholesterolaemic effect in rats fed on the low- and high-fat diets, but decreased the cholesterol content of VLDL and lowered serum triglycerides and VLDL-tryglycerides when the high-fat diet was given.

4. Purified cellulose had no significant effect on plasma lipids.

5. As shown by multivariance analysis, low-methoxyl pectin and wheat bran both beneficially modified the serum triglyceride and cholesterol variables except VLDL-triglycerides. However, the magnitude of the effect of each individual type of fibre was dependent on the fat and cholesterol content of the diet, suggesting the existence of different mechanisms of action.
Protein–energy malnutrition in pregnant rats improves the adaptation of the endocrine pancreas in malnourished offspring and induces insulin resistance after rehabilitation
Authors: Dollet Jean-Marc , Beck Bernard , Max Jean-Pierre , Debry Gérard
Published: September 2005

1. In developing countries, malnutrition begins during pregnancy and lactation. Glucose intolerance is a problem of importance during protein-energy malnutrition (PEM). We therefore studied glucose homeostasis in rats weaned from undernourished mothers.

2. On weaning, 156 mde Wistar rats, born from deprived mothers (75 g casein/kg diet), were fed ad lib on either a balanced diet (180 g casein/kg; group DR), or a protein-deficient diet (50 g casein/kg; group DD). At seven time intervals (weeks 0, 1, 3, 5, 8, 16 and 23) twelve rats were weighed, fasted overnight and then decapitated. Blood glucose, plasma insulin (IRI) and glucagon (IRG) levels and pancreatic insulin and glucagon contents were determined.

3. In DR and DD rats blood glucose, which was normal at weaning, dropped in the 1st week and then increased slowly. DR rats were hyperglycaemic from week 16. IRI continually increased during the experiment from near-normal values to hyperinsulinic levels in DR rats; in group DD, it remained stable until week 8 before increasing. IRG, which was very low at weaning, increased to normal levels in the 1st week in group DR; in group DD, it fell slightly during the study. Pancreatic hormone contents were much higher than after normal pregnancy and lactation.

4. We compared these results with those of a previous study with rats born from normal mothers: at weaning in the second experiment the rats were already well adapted to malnutrition. The plasma ratio IRI:IRG in DD rats showed two phases of adaptation: weeks 0–5 when glucose homeostasis did not change and weeks 5–23 when it became increasingly normal. At the end of the experiment DR rats still had a lower body-weight than normal rats but were insulin-resistant.
Effect of insulin on hind-limb and whole-body leucine and protein metabolism in fed and fasted lambs
Authors: Oddy V. H. , Lindsay D. B. , Barker P. J. , Northrop A. J.
Published: September 2005

1. A combination of isotope-dilution and arterio-venous difference techniques was used to determine rates of leucine metabolism and protein synthesis and degradation in a hind-limb preparation (predominantly muscle) and the whole body of eight lambs fed on milk to appetite and eight lambs fasted from 24 to 48 h.

2. Compared with fed lambs, fasted lambs showed decreased rates of protein synthesis in both whole body and hind-limb, and in hind-limb muscle, elevated rates of protein degradation.

3. The effects of two rates of insulin infusion on whole-body and hind-limb-muscle leucine metabolism, and in turn on protein metabolism, were determined. Insulin had no significant effect on leucine flux or oxidation (and hence protein synthesis and degradation) in whole-body or hind-limb muscle of fed lambs. In fasted lambs insulin progressively reduced arterial leucine concentration and whole-body leucine flux and oxidation, indicating a reduction in both protein synthesis and degradation. Insulin reduced the rate of leucine efflux from hind-limb muscle, which was followed by a reduction in leucine uptake. Insulin increased hind-limb-muscle glucose uptake in both fed and fasted lambs.

4. On the basis that hind-limb muscle was representative of skeletal muscle in general, we estimated that muscle accounted for the same percentage (about 27) of whole-body protein synthesis in both fed and fasted lambs. This percentage was unaffected by infusion of insulin, although the absolute rates differed in fed and fasted lambs.
Tissue folates in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced vitamin B12deficiency and neurological impairment
Authors: Van Der Westhuyzen Justin , Davis Richard E. , Icke Graham C. , Metz Jack
Published: September 2005

1. Long-term exposure of the fruit bat Rousettus aegyptiacus to nitrous oxide, which inactivates methylco balamin, leads to neurological impairment and ataxia.

2. In N2, O-exposed animals, liver concentrations of total folates and methyl folates decreased to less than one fifth that of control animals. Pediococcus cerevisiue-active folates were also reduced.

3. In brain, there were no changes in total or methyl folates, but P.cerevisiae-active folates were lower in N2, O-exposed animals.

4. Supplementation with methionine retarded the development of neurological impairment and the fall in liver total and methyl folates, but not that in P. cerevisiae-active folates.

5. Supplementation with serine failed to retard the development of neurological impairment or fall in hepatic folates.

6. The present results suggest that the N2O-induced neurological impairment in the bat is not related to depletion of cerebral folates, but do not exclude changes in the subcellular distribution of folates.
Heinz body anaemia in lambs with deficiencies of copper or selenium
Authors: Suttle N. F. , Jones D. G. , Woolliams C. , Woolliams J. A.
Published: September 2005

1. The progression of Heinz body anaemia was studied in groups of lambs of low- and high-copper status, produced through breeding or Cu supplementation, when they were transferred from improved pasture to rape (Brassica napus L.) in autumn. Some lambs had previously received selenium by injection. The Cu and Se supplements markedly increased superoxide dismutase (EC 1. 15. 1. 1; SOD) and glutathione peroxidase (EC 1. 11. 1. 9; GSHPx) activities respectively in the erythrocytes, and both supplements had elicited growth responses at pasture.

2. At the time of transfer to rape, lambs not treated with Cu had lower whole-blood haemoglobin (Hb) concentrations and a higher percentage of erythrocytes containing Heinz bodies (6.6 v. 3.7%, P < 0.01) than Cu-treated lambs: the corresponding effects of Se treatment were similar in direction but lower in magnitude (P < 005).

3. After grazing rape for 2 weeks the mean Hb concentration had fallen by 30 g/l while Heinz body count had increased from 5 to 25%. However, counts were negatively correlated with the initial values and were unaffected by the Cu and Se treatments which maintained high plasma Cu concentrations and SOD and GSHPx activities.

4. The results provide the first evidence that Cu deficiency can induce Heinz body formation and the anaemia in grazing Cu-deficient lambs may be partly haemolytic in origin. The concomitant Se deficiency added marginally to the problem but neither the separate nor combined deficiencies increased the susceptibility of lambs to brassica anaemia.
The effect of the preceding day's protein intake on basal metabolic rates in young adults
Authors: Soares M. J. , Sequeira Jennifer , Shetty P. S.
Published: September 2005

1. Changes in basal metabolic rates (BMR), following alterations in the preceding day's dietary protein (8.6, 11.5 and 14.0% of energy) were studied in eight, young, healthy adults over 4d.

2. Results showed a significant training effect, with BMR values 4.8 % lower on day 4 of the study period. Analysis of the results by ANOVA revealed a significant interaction between subjects and diets (P<0.005), a significant difference between subjects but no differences in BMR due to the protein content of the diets.

3. Mean coefficient of variation (CV) for intra- and inter-individual differences in BMR from day-to-day was of the order of 4 and 9% respectively.

4. Changes in protein content of the preceding day's diet do not influence variations in BMR which appear to be random in nature with a true CV of 3.8%.
The effect of meal composition on the degree of satiation following a test meal and possible mechanisms involved
Authors: Driver Christopher J. I.
Published: September 2005

1. Possible links between metabolism and satiation were investigated using volunteer subjects given test meals based on milk solids. Satisfaction was rated by the subjects on a six-point scale and the course of metabolism was followed by measurement of the respiratory quotient (RQ).

2. The time-course of satiation was the same for a high-carbohydrate, a high-fat and a high-protein meal, in spite of the very different time-course of metabolism. The degree of satiation was reduced by added sodium chloride, without affecting the RQ rise. On the other hand, calcium chloride produced a suppression of the RQ rise without altering the satiation.

3. It is proposed that the results indicate that the primary receptors responsible for post-prandial satiation lie within the gut wall and that there is probably a number of receptor types. Likely candidates for these receptors are the gut hormone-secreting cells.

4. Although very-low-protein meals produce less satiation than meals containing 220 g protein/kg dry weight, there is no additional satiation obtained by increasing the protein level further. This is not inconsistent with the possibility of a protein hunger separate from an energy hunger.
Long-term evaluation of the adequacy of habitual diets to provide protein needs of adult Nigerian men
Authors: Atinmo T. , Egun G. , Mbofung C. M. F.
Published: September 2005

1. A continuous 40 d metabolic nitrogen balance study was conducted on twelve young men aged 25 (sd 2.6) years to evaluate the adequacy of a previously determined safe level of protein intake.

2. Subjects were fed on diets which they were habitually accustomed to and which provided a protein level of 0.75 g protein (N × 6.25)/kg body-weight per d as the safe level and an energy intake level of 0.2 MJ/kg body-weight per d. N balances, including an estimate for integumental losses as well as certain biochemical variables, were determined for the last 5 d of two consecutive 20 d diet periods.

3. Only two of the twelve subjects were observed to be in negative N balance during the final 5 d of the 40 d period. N balance was generally positive at 8.24 (sd 8.61) mg N/kg body-weight, thus confirming the adequacy of 0.75 g protein/kg body-weight per d as a safe level of protein intake in the majority of the subjects.
The relation between bacterial degradation of viscous polysaccharides and stool output in human beings
Authors: Tomlin J. , Read N. W.
Published: September 2005

1. The relation between bacterial degradation of three viscous polysaccharides (guar gum, ispaghula and xanthan gum) by colonic bacteria in vitro and their effects on colonic function were investigated by comparing the results of anaerobic in vitro incubations with fresh faeces from seven healthy volunteers (measuring viscosity, pH and gas production) with the effects of feeding all three polysaccharides to the same volunteers for 1 week each (14–15 g/d) on faecal mass and whole-gut transit time.

2. Guar gum was rapidly fermented in vitro by faecal bacteria from all volunteers with concomitant loss of viscosity, reduction in pH and generation of gases. Ispaghula maintained its viscosity during incubation, but the pH fell significantly. The results of xanthan gum incubations showed considerable individual variation.

3. Only ispaghula significantly increased faecal mass, whilst none of the gums significantly affected stool frequency or transit time. Statistical analysis of the pooled results showed that although transit time and faecal output were inversely related, feeding viscous polysaccharides could influence these indices independently. Stool frequency was significantly correlated with the transit time, but not the faecal output.

4. Transit time was reduced by gum feeding to a significantly greater extent in those subjects whose faecal bacteria reduced or removed the viscosity of that gum, than in those subjects where the viscosity was maintained. In contrast, there was a smaller increase in faecal mass when the viscosity of the appropriate cultures was removed than when it was maintained or reduced. Increases in stool frequency were significantly associated with hydrogen production from in vitro cultures.
Impact of maternal iron deficiency on quality and quantity of milk ingested by neonatal rats
Authors: O'Connor Deborah L. , Picciano Mary Frances , Sherman Adria R.
Published: September 2005

1. The effect of maternal iron deficiency on milk composition and consumption by sucking rats was investigated.

2. Dams (n42) were fed on semi-purified diets with either 8 (Fe-) or 250 (Fe+) mg Fe as ferrous sulphate/kg throughout gestation and lactation. Total milk intake was determined at days 7, 12 and 17 of lactation from the rate of disappearance of3H2O from the total body water pool of pups. Measurements of milk constituents and Fe status of animals also were made.

3. Feeding the Fe- diet led to the development of anaemia in dams and pups and to growth retardation of sucking pups.

4. Concentrations of total lipid and Fe in milk from Fe- dams were significantly lower than those from Fe + dams. Mean milk intakes (ml/d) of Fe-deficient pups were 21 and 28% less than intakes of Fe-sufficient pups on days 12 and 17 respectively. However, when expressed per kg body-weight, mean milk intakes were similar between groups on days 17 and 12 and increased by 47% in the Fe-deficient group on day 17 of lactation.

5. It is concluded that maternal Fe deficiency affects the quality of milk ingested by neonatal rats. However, Fe-deficient pups are at least partially able to compensate for reduced milk energy and nutrient contents by increasing intake in late lactation.
Effect of reduced dietary zinc intake on carbohydrate and Zn metabolism in the genetically diabetic mouse (C57BL/KsJ db+/db+)
Authors: Southon Susan , Kechrid Z. , Wright A. J. A. , Fairweather-Tait Susan J.
Published: September 2005

1. Male, 4–5-week-old, genetically diabetic mice (C57BL/KsJ db/db) and non-diabetic heterozygote litter-mates (C57BL/KsJ db/+)were fed on a diet containing 1 mg zinc/kg (low-Zn groups) or 54 mg Zn/kg (control groups) for 27 d. Food intakes and body-weight gain were recorded regularly. On day 28, after an overnight fast, animals were killed and blood glucose and insulin concentrations, liver glycogen, and femur and pancreatic Zn concentrations were determined.

2. The consumption of the low-Zn diet had only a minimal effect on the Zn status of the mice as indicated by growth rate, food intake and femur and pancreatic Zn concentrations. In fact, diabetic mice fed on the low-Zn diet had a higher total food intake than those fed on the control diet. The low-Zn diabetic mice had higher fasting blood glucose and liver glycogen levels than their control counterparts. Fasting blood insulin concentration was unaffected by dietary regimen.

3. A second experiment was performed in which the rate of loss of 65Zn, injected subcutaneously, was measured by whole-body counting in the two mouse genotypes over a 28 d period, from 4 to 5 weeks of age. The influence of feeding low-Zn or control diets was also examined. At the end of the study femur and pancreatic Zn and non-fasting blood glucose levels were determined.

4. All mice fed on the low-Zn diet showed a marked reduction in whole-body 65Zn loss compared with those animals fed on the control diet. In the low-Zn groups, the loss of 65Zn from the diabetic mice was significantly greater than that from heterozygote mice. This difference was not observed in the control groups. Blood glucose levels were elevated in the low-Zn groups. Possible reasons for these observations are discussed.

5. The present study demonstrates an adverse effect of reduced dietary Zn intake on glucose utilization in the genetically diabetic mouse, which occurred before any significant tissue Zn depletion became apparent.
The synthesis in vivo of proteins in various tissues in chickens adapted to intermittent feeding
Authors: Pinchasov Y. , Nir I. , Nitsan Zafrira
Published: September 2005

1. Protein synthesis was estimated in vivo in breast (superficial pectoral) and tibia (gastrocnemius) muscles, liver, kidney, pancreas, crop, duodenum, jejunum and ileum, using L-[U-14C]lysine injection. The effect on incorporation of [14C]lysine 1 and 2 h after injection was examined in five chickens adapted or not adapted to intermittent feeding.

2. Incorporation of [14C]lysine into tissue decreased in magnitude in the following descending order: pancreas > jejunum, duodenum > ileum, crop, liver > kidney > tibia, breast muscle and blood plasma.

3. The incorporation of [14C]lysine into muscle protein was higher in chicks after 24 h of refeeding than after 24 h of food deprivation. These differences were higher in adapted than in non-adapted birds. On days of refeeding the rate of incorporation exceeded that found in chickens fed ad lib.

4. Bound 14C from lysine in the intestinal segments was less than in control birds after food deprivation and greater after refeeding in non-adapted chicks only.

5. A negative relation was observed between bound and free 14C in muscles and in other tissues.

6. Short- and long-term adaptations to feeding regimens are discussed.
Relations between plasma non-esterified fatty acid metabolism and body tissue mobilization during chronic undernutrition in goats
Authors: Dunshea F. R. , Bell A. W. , Trigg T. E.
Published: September 2005

1. Eleven mature goats were offered 140 kJ metabolizable energy/kg per d (M) of lucerne (Medicago sativa) hay-oaten grain (1:1, w/w) for at least 1 month before plasma non-esterified fatty acid (NEFA) kinetics and tritiated water space (TS) were determined.

2. Goats were then fed at M, 0.5 M or 0.25 M for 34 (se 6) d, at which time the experimental procedures were repeated.

3. Chronic undernutrition resulted in elevated NEFA concentrations and NEFA entry rate, with a tendency for the ratio plasma NEFA:glycerol to increase, suggesting that body-fat mobilization during prolonged underfeeding is due more to decreased lipogenesis and intracellular NEFA re-esterification rather than to increased lipolysis.

4. Plasma NEFA concentrations and NEFA entry rate, as well as being highly correlated with each other, were significantly related to calculated energy balance and body fat losses estimated from changes in live weight and TS.

5. Increases in NEFA entry rate were highly correlated with, and of the same magnitude as, body fat losses, confirming that NEFA kinetics do quantitatively reflect lipid mobilization.