bluuebunny/crossref_metadata_2025 huggingface dataset:
Accumulation of polyunsaturates is decreased by weight-cycling: whole-body analysis in young, growing rats
Authors: Chen Zhen-Yu , Menard Chantale R. , Cunnane Stephen C.
Published: September 2005

Whole-body fatty acid analysis in rats has previously shown that 50–70% of dietary linoleate and α-linolenate is β-oxidized to CO2and that this value increases with refeeding after a single episode of fasting. Our hypothesis was that repeated fasting-refeeding or weight-cycling would increase the β-oxidation of linoleate and α-linolenate thereby depleting their whole-body levels. In rats consuming 3% energy as linoleate and 0·15 % energy as α-linolenate during a 16 d balance period, 19% of the linoleate consumed accumulated in weight-cycled rats compared with 34% in the free-fed controls (P < 0.01). Similarly, 11% of the α-linolenate consumed accumulated in the weight-cycled rats compared with 22% in the controls (P < 0.01). Arachidonate and docosahexaenoate also accumulated to lower extents in the weight-cycled rats than in the controls. In contrast, whole-body accumulation of palmitate, stearate and oleate was not different between the weight-cycled group and the controls when measured as a proportion of intake or relative to weight gain. Thus, whole-body depletion of linoleate and α-linolenate did not occurper se but the partitioning of linoleate and α-linolenate was significantly altered by weight-cycling resulting in lower whole-body accumulation and higher apparent oxidation of all polyunsaturates especially linoleate and α-linolenate.
Measurement of body fat in young and elderly women: comparison between a four-compartment model and widely used reference methods
Authors: Bergsma–Kadijk Janneke A. , Baumeister Brigitte , Deurenberg Paul
Published: September 2005

Body composition was measured in twenty young females aged 19−27 years and eighteen elderly females, aged 65−78 years by densitometry (underwater weighing), deuterium oxide dilution and dual-energy X-ray absorptiometry (DXA). From body weight, bone-mineral content, total body water and body density, percentage body fat (BF%) was calculated using a four-compartment model. BF% abtained by this four-compartment model was regarded as a reference method and BF% obtained by the single methods were compared with this value. Differences in BF% from the four-compartment model minus the single methods were 2·1 (SD 1·2) for densitometry, 3·1 (SD 1·8) for DXA and -0·6 (SD 0·9) BF% for deuterium oxide dilution in the young women. In the elderly women these values were -0·6 (SD 2·3), 5·3 (SD 3·8) and 0·7 (SD 2·2) BF%. When a three-compartment model (calculated from body density and total body water) was compared with the four-compartment model, the bias was 0·4 (SD 0·3) BF% in the young and 0·0 (SD 0·3) BF% in the elderly women. From the mineral and water fractions in the fat-free mass the true density of the fat-free mass was calculated as 1·1070 (SD 0·0047) kg/l in the young females and 1·0970 (SD 0·0088) kg/l in the elderly women (P<0·001). This study shows that the single methods have considerable mean and individual biases compared with the four-compartment model, but that a three-compartment model calculated from density and total body water offers an acceptable alternative. The difference in calculated density of the fat-free mass between the young and the elderly women shows the need to adapt Siri's formula for specific groups.
Rebalancing essential amino acids intake by self-selection in the rat
Authors: Fromentin Gilles , Nicolaidis Stylianos
Published: September 2005

The purpose of the present study was to assess whether rats are capable of selecting the right proportions of two diets that are individually inappropriate in terms of essential amino acid composition to satisfy their amino acid requirements. Rats were offered a choice of one protein-free regimen and another devoid of only one essential amino acid (either threonine or isoleucine) set up in such a way as to provide amino acid balance if they were consumed in 1/3 and 2/3 proportions respectively. Preliminary experiments had established that all our diets were aversive by themselves except for the 60 g casein/kg diet. Rats did reach almost the necessary proportion with, according to published standards (National Research Council, 1978), some excess in isoleucine intake. In addition, given access to two aversive diets that were each nutritionally inadequate, rats showed no aversion and gained body weight when they had the opportunity to consume both of them. Beyond the capacity that rats have of rebalancing their micronutrient intake, the present experiment brings out the idea that the imbalance-induced aversion: preference ratio may be completely upset when this omnivore has access to more than one feed.
The effect of cottonseed condensed tannins on the ileal digestibility of amino acids in casein and cottonseed kernel
Authors: Yu Feng , Moughan P. J. , Barry T. N.
Published: September 2005

The effect of adding cottonseed hulls to casein- and cottonseed-kernel-based diets on the apparent and true ileal digestibility of N and amino acids, and the proportion of this effect accounted for by condensed tannin (CT), were determined using the growing rat. Sixtyrats were allocated randomly to ten semi- purified diets, containing either casein (four diets) or purified unheated solvent-extracted cottonseed kernel (six diets) as the sole protein source, with Cr2O3added as an indigestible marker. Two of the casein diets contained no hulls whilst the remaining two diets contained 70 g cottonseed hulls/kg. Two of the cottonseed-kernel-based diets contained no hulls, with two containing 23 g hulls/kg and the remaining two containing 46 g hulls/kg. For each pair of diets, PEG was either included or excluded. The effect of CT was quantified by comparing control rats (-PEG; CTacting) with PEG-supplemented rats (+PEG; CT inactivated) at each level of dietary hulls. The rats were given their respective experimental diets for 14 d. Each rat was given the food ad libitumfor 10 min hourly from 08·00 to 18·00 hours. On day 14, samples of digesta were collected at death from the terminal 150 mm of ileum at 7 h from the first meal. Apparent and true ileal digestibilities were calculated for DM, N and the individual amino acids. The principal finding was that the inclusion of hulls depressed the apparent and true ileal digestibilities of N and amino acids, but with the response differing between diets. With the casein-based diet the mean apparent and true ileal amino acid digestibilities were significantly depressed from 0·89 and 0·96 to 0·85 and 0·92 respectively, by the inclusion of 70 g hulls/kg in the diet, and addition of PEG then restored these to 0·89 and 0·95. All of the depression could be explained by the CT content of the hulls. However, with the cottonseed-kernel-based diet the responses fell into three categories. The apparent and true ileal digestibilities of the essential amino acids cystine and methionine were not affected by hull addition, ileal digestibilities of leucine, isoleucine, lysine, threonine and valine were markedly depressed by hull addition with approximately 50% of the depression being explained by CT, whilst the ileal digestibilities of histidine, arginine and phenylalanine were depressed by hull addition but little or none of this effect could be explained by CT. Thus the effect of hulls on protein digestion clearly differed with source of protein. With the cottonseed-kernel-based diet it seems that components of the hulls other than CT also depressed the apparent and true ileal digestibilities of N and amino acids. The identity of these components is unknown.
Effects of long-term low-glycaemic index starchy food on plasma glucose and lipid concentrations and adipose tissue cellularity in normal and diabetic rats
Authors: Lerer-Metzger Muriel , Rizkallal Salwa W. , Luo Jing , Champ Martine , Kabir Morvarid , Bruzzo FranÇoise , Bornet Francis , Slama GÉrard
Published: September 2005

The present study aimed to assess the metabolic consequences of the chronic ingestion of two starches giving different postprandial glycaemic responses in normal and diabetic rats. The two starches chosen were mung-bean (Phaseolus aureus) starch (97% pure starch) and wheat starch presented as ground French toast. First, we studied the characteristics of these two starches.In vitrothe α-amylase (EC3.2.1.1) digestibilities of these starches were 40 (SE 3) and 62 (SE 4)% respectively at 30 min, whereas the contents of resistant starch were 77 (SE 4) and 22 (SE 4) g/kg respectively.In vivothe mung-bean starch produced lower postprandial glycaemic responses than the wheat starch (areas under the curve were: 91 (SE 28) and 208 (SE 33) mmol.min/I, P < 0·05) in normal rats (n 8). We then submitted twenty-eight normal and twenty-eight diabetic (neonatal streptozotocin on second day of birth) male Sprague-Dawley rats (6 weeks old) to a diet containing 570 g starch/kg as either mung-bean starch or wheat starch (n 14 rats/group). After 5 weeks on the diets food intakes and body weights were identical in each group. Liver and kidney weights were comparable when expressed as relative weight. The mung-bean-starch diet slightly decreased epididymal fat-pad weight (P < 0·14, ANOVA) and led to a marked decrease in adipocyte volume (P < 0·05). Plasma triacylglycerol and phospholipid concentrations were lower after the mung-bean-starch diet than after the wheat-starch diet in both normal and diabetic rats, whereas free fatty acid concentrations were lower only in normal rats. Similarly, non-fasting plasma glucose concentrations decreased (P < 0·05) in normal rats fed on mung-bean starch but not in diabetic ones (P < 0·14). Insulin levels tended to be lower, but not significantly, after mung-bean-starch feeding than after wheat starch. We conclude that the replacement of 570 g wheat starch/kg diet with mung-bean starch for 5 weeks resulted in (1) lowered non-fasting plasma glucose and free fatty acid levels in normal but not in diabetic rats, (2) a reduction in plasma triacylglycerol concentration and adipocyte volume in both normal and diabetic rats. Thus, the type of starch mixed into the diet may have important metabolic consequences in normal and diabetic rats
Response of broilers to graded levels of microbial phytase added to maize–soyabean-meal-based diets containing three levels of non-phytate phosphorus
Authors: Kornegay E. T. , Denbow D. M. , Yi Z. , Ravindran V.
Published: September 2005

Male 1-d-old broilers (n 920) were given 0, 200, 400, 600, 800, 1000 and 1200 U microbial pbytase/kg diet in combination with 2·0, 2·7 or 3·4 g non-phytate P (nP)/kg or 4·0, 5·1 or 5·8 g total P (tP)/kg in a 21 d trial to assess the effectiveness of phytase in a maize–soyabean-meal diet. In addition to the above twenty-one diets, a positive control P diet supplied 4·5 g nP/kg, 6·9 g tP/kg and 10 g Ca/kg. The basal diet contained 230g crude protein/kg, 8·8 g Ca/kg, 4·4 g tP/Fg and 2/0 g nP/kg. Defluorinated phosphate and limestone were used to supply P and Ca. A Ca:tP ratio of 2:l was maintained except in the positive control diet which had a ratio of 1·45: 1. Phytase additions linearly increased (P < 0·01) body-weight (SW) gain, feed intake, toe ash percentage, and apparent retention (% of intake) or total amount (g/bird) of retained Ca and P, and linearly decreased (P < 0·01) P excretion (g/kg of DM intake) at each level of nP with the magnitude of the response inversely related to the level of nP. Above-normal mortality was only observed in the group receiving 2·0 g nP/kg diet without phytase. Adding nP linearly increased (P < 0·01) BW gain, feed intake, toe ash percentage, Ca retention, total amount (g/bird) of P retained, and P excretion, and iinearly decreased (P < 0·01) apparent retention (%) of P. Derived linear and non-linear equations for BW gain and toe ash percentage at the two lower nP levels, 2·0 and 2·7 g/kg, were used to calculate P equivalency value of microbial phytase. The results show that 939 U microbial phytase is equivalent to 1 g P from defluorinated phosphate in broilers fed on maize–soyabean-meal diets. The amount of P released per 100 U phytase decreased as the total amount of phytase increased.
Interaction between nutrition and Eimeria acervulina infection in broiler chickens: development of an experimental infection model
Authors: Adams C. , Vahl H. A. , Veldman A.
Published: September 2005

In three experiments broiler chickens were inoculated with sporulated Eimeria acervulina oocysts at 18 d of age. Feed intake, body-weight gain, brush-border enzyme activities, fat digestion, protein digestion and protein retention were measured. Body-weight gain was reduced during the acute phase of the infection and increased during the recovery phase of the infection. Feed intake was decreased on day 4 and day 5 postinfection (PI) and increased from day 7 to day 11 PI. Maltase (EC 3.2.1.20) and sucrase (ECEC 3.2.1.48) activities were decreased on day 5 PI in all intestinal segments. In Expts 2 and 3, however, maltase activity was increased in the ileum. Fat digestion was decreased from day 2 to day 11 PI. N digestion and retention were decreased from day 2 to day 11 PI.
Interaction between nutrition and Eimeria acervulina infection in broiler chickens: diet compositions that improve fat digestion during Eimeria acervulina infection
Authors: Adams C. , Vahl H. A. , Veldman A.
Published: September 2005

Previously an experimental infection model was developed in which broiler chickens were inoculated with sporulated Eimeria acervufina oocysts at an age of 18 d. The infection resulted in adverse performance results and reduced nutrient digestion. In two new experiments with the infection model effects of diet adjustments on fat digestion were investigated. In the first experiment addition of 0·4 g cholic acid/kg to a diet rich in animal fat resulted in increased fat digestion during the infection. In the second experiment replacing animal fat by coconut oil resulted in improved fat digestion during the coccidiosis infection. However, replacement of animal fat by soyabean oil did not improve fat digestion.
Bioavailability of calcium of fresh cheeses, enteral food and mineral water. A study with stable calcium isotopes in young adult women
Authors: Dokkum W. Van , De La Guéronnière V. , Schaafsma G. , Bouley C. , Luten J. , Latgé C.
Published: September 2005

True fractional Ca absorption from six foods was measured in twelve normal healthy women, aged 20–29 years. The tested foods were commercially available fresh cheese, fresh cheese prepared by new technology and rich in Ca, similar cheese with added Fe, enteral food, mineral water alone and combined with a spaghetti meal. The aim of the study was to investigate: (1) Ca absorption from a new Ca-rich fresh cheese and to compare it with that from the traditional commercial type of fresh cheese; (2) the effect of Fe enrichment of the new cheese on Ca absorption; (3) Ca absorption from the mineral water and the enteral product and to compare it with that from the dairy products; (4) the effect of a meal combined with the mineral water on Ca absorption. All test foods were consumed by all subjects according to a design with two Latin squares. Each treatment of 2 d was followed by a wash-out period of 2 weeks. Ca absorption was measured using a double stable-isotope (44Ca and 48Ca) extrinsic labelling technique. Mean fractional Ca absorption from the new fresh cheese was not significantly different from that from the traditional type (37·7 (SD 10·2)% v. 42·2 (SD 11·6)%). The addition of Fe to the new cheese did not significantly influence Ca absorption. Ca-absorption values from the mineral water (37·0 (SD 98) %) and from the enterd product (42·6 (SD 11·4)%) were not significantly different from those from the dairy products (37·7–42·2%, SD 10·2–11·6%). The co-ingestion of a spaghetti meal with the mineral water significantly enhanced Ca absorption from 37 (SD 9·8)% to 46·1 (SD 11·7)%. It is concluded that a new process leading to a fresh cheese with a higher Ca concentration does not alter Ca bioavailability compared with the standard technology and for a constant Ca supply. Thus this new fresh cheese would probably provide more Ca than the standard one. The fractional Ca-absorption values for mineral water and the enteral product indicate that these products can make an interesting contribution to Ca supply for populations with a low Ca intake and patients with specilic diseases respectively.
Relationship between dietary iron intake, corrected for diet reporting error, and serum ferritin in Danish women aged 35–65 years
Authors: Heitmann Berit Lilienthal , Milman Nils , Hansen Gitte Laub
Published: September 2005

Several studies have failed to demonstrate an association between Fe status and intake of dietary Fe. However, in the long term, it Seems logical to presume that body Fe reserves are, fundamentally, dependent on the intake of bioavailpble dietary Fe. This discrepancy may depend on several factors(1)interindividual variation in biological availability of dietary Fe (differences in intestinal absorption),(2) interactions between dietary Fe and absorption enhancers and inbibitors, (3) variatiom in physiological (menstruation, childbirth) or unphysiological (blood donation) Fe losses, (4) the failure to adjust dietary intake data for Fe supplements, (5) uncertain food composition data (discrepancies between calculated and chemically measured Fe content inthe diet), and (6) diet reporting error (reported intake of dietary Fe may deviate considerably from the true intake). The present study examined associations between dietary intake of Fe (assessed by diet history interview) and Fe status (assessed by femtin status) among 167 Danish women aged 35–65 years, who were not blood donors, by taking into account diet reporting error (assessed fromp-amino benzoic acid-validated urinary N), physiological blood losses (menstruation, Childbirth, abortions), and Fe supplementation. Our results indicate that the lack of a general association between Fe status and dietary Fe intake may, in part, be caused by selective dietreporting error.
Long-term supplementation with selenate and selenomethionine: urinary excretion by New Zealand women
Authors: Robinson Marion F. , Thomson Christine D. , Jenkinson Christopher P. , Luzhen Gu , Whanger Philip D
Published: September 2005

Thirty-six New Zealand women aged between 18 and 23 years received daily for 32 weeks, 200 µg Se as Se-enriched yeast (selenomethionine, SeMet), or brewer's yeast mixed with selenate, or no added Se (placebo) in a double-blind trial. Mean daily Se excretion increased with both supplements; the selenate group excreted more than the SeMet group, 123v. 66 µg/d respectively at week 2, equivalent to 57v. 27 % of the dose. Thereafter Se output increased for the SeMet group reaching a plateau at about 100 µg/d at week 16, when plasma Se had also plateaued at 190 ng/ml. The selenate group had reached an earlier plateau of 110 ng Se/ml at week 7. There was a close relationship between 24 h urine and plasma Se for the SeMet group but not for the selenate group. Renal plasma clearances showed two distinctly different responses; the clearance of 0·4 ml/min reached by the SeMet group at week 2 plateaued as plasma Se increased almost 2-fold; whereas for the selenate group the clearance varied between 0·8 and 1·1 ml/min whilst plasma Se remained almost constant at 110 ng/ml. Previous studies, also of 200 µgSe/d as Se-rich bread, in New Zealand (NZ) and elsewhere showed similar responses to Se-yeast; the selenite response was intermediate between selenate and Se-yeast (SeMet). The full significance of these studies awaits identification of Se components in plasma, glomerular filtrate and urine; meanwhile renal clearances serve as a pointer to changes in the distribution of Se-containing fractions in the plasma. Trimethylselenonium was detected in basal urines, and was a minor component in urines of supplemented NZ subjects at about 1 % of the total Se.
Excretion of benzoic acid derivatives in urine of sheep given intraruminal infusions of 3-phenylpropionic and cyclohexanecarboxylic acids
Authors: Pagella J. H. , Chen X. B. , Macleod N. A. , Ørskov E. R. , Dewey P. J. S.
Published: September 2005

The quantitative relationship between the urinary excretion of benzoic acid (BA)and the uptake of 3-phenylpropionic (PPA) and cyclohexanecarboxylic (CHCA) acids was assessed.PPA and CHCA are produced in the rumen by microbial fermentation of lignocellulosic feeds and metabolized, after absorption, to BA which is excreted in the urine mainly as its glycine conjugate hippuric acid (HA). Four sheep nourished by intragastric infusions of all nutrients weregiven continuous ruminal infusions of PPA (8,16 or 24 mmol/d) either alone or with CHCA (8 or 16 mmol/d) in a factorial experiment. The treatments were allocated to ten consecutive 6 d periods, with a control being repeated at periods 1, 5 and 10. PPA and CHCA ruminal absorption rates, estimated using the liquid-phase marker Cr-EDTA, were 0·78 (SD 0·29)/h and 0·88 (SD 0·28)/h respectively. For the control, HA excretion was only 0·22 (SD 0·33) mmol/d and free BA was absent. For the other treatments, both HA and free BA were present and HA accounted for 0·85 (SD 0·05) of total BA. The urinary excretion of total BA showed a significant linear correlation (r = 0·997, P<0·001) with the amounts of PPA and CHCA infused. The urinary recovery of infused PPA and CHCA as total BA was 0·79 (SE 0·01). Faecal excretion of BA and its precursors was negligible. Results of this study show that urinary total BA is a potential estimator of the absorption of PPA + CHCA produced in the rumen
Effect of dietary fats rich in lauric, myristic, palmitic, oleic or linoleic acid on plasma, hepatic and biliary lipids in cholesterol-fed hamsters
Authors: Trautwein Elke A. , Kunath-Rau Angelika , Dietrich Juliane , Drusch Stephan , Erbersdobler Helmut F.
Published: September 2005

Effects of different dietary fats on plasma, hepatic and biliary lipids were determined in male golden Syrian hamsters (Mesocricetus auratus) fed on purified diets for 7 weeks. Diets were made by blending different fats containing characteristic fatty acids: butter (14:0 + 16:0), palm stearin (16:0), coconut oil (12:0 + 14:0), rapeseed oil (18:1), olive oil (18:l) and sunflowerseed oil (18:2). In all diets except the sunflowerseed oil diet dietary 18:2 was held constant at 2% energy. Total fat supplied 12% of energy and cholesterol was added at 4 g/kg diet. Plasma cholesterol and triacyglycerol concentrations were increased by dietary cholesterol. After 7 weeks, plasma cholesterol concentrations were highest with the palm Stearin, coconut oil and olive oil diets (8·9, 8·9 and 9·2 mmol/l) and lowest with the rapeseed oil and sdowerseed oil diets (6·7 and 5·5 mmol/l) while the butter diet was intermediate (8·5 mmol/l). Hepatic cholesterol concentration was highest in hamsters fed on the olive oil diet and lowest with the palm stearin diet (228v. 144 µmol/g liver). Biliary lipids, lithogenic index and bile acid profile of the gall-bladder bile did not differ significantly among the six diets. Although the gallstone incidence was generally low in this study, three out of 10 hamsters fed on the palm stearin diet developed cholesterol gallstones. In contrast, no cholesterol gallstones were found with the other diets. Rapeseed and dowerseed oils caused the lowest plasma cholesterol and triacyglycerol concentrations whereas olive oil failed to demonstrate a cholesterol-lowering effect compared with diets rich in saturated fatty acids. Since 18:2 was kept constant at 2% of energy in all diets, the different responses to rapeseed and olive oils could possibly be attributed to their different contents of 16:0 (5·6 %v. 12·8% respectively). Other possible explanations are discussed.
Linoleic and α-linolenic acids differently modify the effects of elaidic acid on polyunsaturated fatty acid metabolism and some immune indices in rats
Authors: Koga Tamiho , Nonaka Michiko , Gu Jiong Yan , Sugano Michihiro
Published: September 2005

To explore whether the metabolic responses totrans, compared withcis, fatty acids depend on the source of dietary polyunsaturated fatty acids (PUFA), male Sprague-Dawley rats, 5 weeks old, were fed on diets containing 30 g oleic (cis) or elaidic (trans) acids/kg in combination with either 70 g perilla oil (α-linolenic acid) or safflowerseed oil (linoleic acid)/kg for 3 weeks in separate experiments. The dietary fats were adjusted to have the same level of total PUFA. The dietary manipulation did not influence the growth indices, but spleen weight was greater when the dietary PUFA source was perilla oil. The incorporation oftransfatty acid into liver phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine and adipose tissue lipids, particularly phospholipids, was significantly higher when rats were fed on safflowerseed oil compared with perilla oil. However, only limited differences were observed in the effects ofcisandtransfatty acids on the proportions of PUFA in liver phospholipids. Splenic production of prostaglandin E2was reduced bytransfatty acid when safflowerseed oil was the PUFA source, but notranseffect was observed on leukotriene C4production. Dietary PUFA significantly influenced the concentration of plasma immunoglobulins (Ig) but the effect of geometry was only seen in IgG which was increased bytransacid. Dietarytransfatty acid increased the CD4+: CD8+T-lymphocyte ratio in the spleen, reflecting a decreasing trend of the proportion of CD8+, when combined with perilla oil. These observations indicate that the type of PUFA simultaneously ingested specifically infiuences the effect thattransacid exerts on PUFA metabolism, eicosanoid production and some immune indices.
Dietary fat affects lipids and anti-cardiolipin antibody levels in autoimmune-prone NZB/W F1 mice
Authors: Lin Bi-Fong , Jeng Su-Jen , Chiang Bor-Luen , Huang Chao-Chi
Published: September 2005

Studies in autoimmune-prone NZB/W F1 mice have demonstrated that the amount of dietary fat can affect autoantibody production and the disease course of autoimmune diseases. Anti-cardiolipin antibodies have been found to play a major role in thrombus formation and the increase of abortion rate in both human lupus patients and murine lupus. The present study investigated further the effect of dietary fat on lipid and anti-cardiolipin antibody production in autoimmune-prone mice. Two groups of NZB/W F1 mice were fed on diets containing 200 g dietary fat/kg and 50 g dietary fat/kg respectively, the fat being composed of equal amounts of lard and soyabean oil. Serum levels of lipids, immunoglobulin (Ig) anti-single stranded DNA and anti-cardiolipin antibodies were followed regularly every month and mice were killed forin vitroexperiments after 5 months on the experimental diets. The results showed that serum triacylglycerol concentration was lower in mice fed on the high-fat diet than in those fed on 50 g fat/kg. There was no significant difference in hepatic lipid contents; however, the fatty acid contents were different between these two groups. Hepatic linoleic acid (18:2n−6) and arachidonic acid (20:4n−6) concentrations were higher in mice fed on the high-fat diet. There were no significant differences in serum IgM concentrations or IgM anti-cardiolipin antibody levels between these two groups. However, IgG anti-cardiolipin antibody levels were higher in mice fed on the high-fat diet at the age of 3–4 months. Total serum IgG concentration was noted to be higher, but in contrast, serum IgA was lower, in the high-dietary-fat group. These findings suggest that high dietary fat may affect lipid metabolism and autoantibody levels in autoimmune diseases
Low-sodium diet in pregnancy: effects on blood pressure and maternal nutritional status
Authors: Van Der Maten Gerrieke D , Van Raaij Joop M. A , Visman Leontien , Van Der Heijden Lidwien J. M , Oosterbaan Herman P , De Boer Rinze , Eskes Tom K.A.B , Hautvast Joseph G.A.J
Published: September 2005

In ninety-four Dutch nulliparous women the effects of a low-Na diet in pregnancy on blood pressure, energy and nutrient intake, Ca metabolism, Zn and Mg status and body composition were studied longitudinally. The women were randomly divided into an intervention group (n41), which used a low-Na diet (mean urinary Na excretion 61 mmol/24 h) from week 14 of pregnancy until delivery and a control group (n53; mean urinary Na excretion 142 mmol/24 h). No effect of the diet on blood pressure was observed. The use of a low-Na diet resulted in significantly reduced intakes of energy, protein, carbohydrates, fat, Ca, Zn, Mg, Fe and cholesterol. However, the women on the low-Na diet appeared to be able to adapt quite well to the reduced intake since Ca, Zn and Mg homeostasis was maintained. In the case of Ca and Mg this was probably due to the observed reduced urinary excretions of these nutrients. Non-significant reductions in weight gain (1·5 kg) and fat-mass gain (0·9 kg) over pregnancy were found in the women on the low-Na diet. No significant effects of the diet on birth weight or placental weight were observed.
Comparison of growth performance and nutrient retention of weaner pigs given diets based on casein, free amino acids or conventional proteins
Authors: Officer D.I , Batterham E. S , Farrell D. J
Published: September 2005

In two experiments the potential value of diets based on casein or free amino acids (FAA) for amino acid utilization experiments were examined. In Expt 1 the optimum dietary electrolyte balance (dEB) for a casein-based diet was estimated by supplemention with 10 or 20 g NaHCO3/kg, to produce diets containing 64, 183 or 302 mmol/kg. In addition, piglet growth performance and efficiency of nutrient deposition of piglets given the casein diets were compared with two multiple protein source diets; Supercreep, a commercial multiple protein source diet or CFS (casein-fish-soyabean-sugar) or a FAA-based diet. Expt 2 was designed to compare piglet response to FAA diet stored at - 15° with twice daily feeding, with FAA diet stored at ambient temperature (13–30°) and offered ad libitum. A CFS diet was used as a positive control and the experiment was conducted over the 10–20 kg growth phase. Expt 1 used forty-eight piglets weaned at 20–22 d of age and allocated to one of six treatments formulated to contain at least 0·84 g lysine/MJ digestible energy in a randomized block design. Piglets given the CFS and Supercreep diets produced superior growth rates (518, 491 g/d) to those given a FAA diet (353 g/d) or casein diet containing 0, 10 or 20 g NaHCO3/kg respectively (365,417,390 g/d) between 5 and 20 kg live weight. Piglets given the casein and FAA diets had higher amino acid digestibilities than those given the Supercreep and CFS diets.The increase in the dEB of the casein diet from 64 to 183 mmol/kg improved piglet growth performance between 5 and 20 kg by 14%. All piglets given casein diets had similar ileal and faecal digestibilities, empty-body compositions, nutrient deposition rates and retention ratios. The results of Expt 2 showed that there was no beneficial effect on piglet performance of storing the FAA diet at -15° and feeding twice daily. Based on the results of these two experiments, neither the casein (0, 10, 20 g NaHCO3/kg) nor FAA diets were suitable for estimating amino acid utilization by the piglet. There remain unidentified factors which limit the growth performance of piglets given the casein and FAA diets.
Uptake and metabolism of propionate in the liver isolated from sheep treated with glucagon
Authors: Ali Abdulhamid Mohamed , Jois Markandeya
Published: September 2005

The uptake and metabolism of propionate in the isolated perfused caudal lobe of the liver and in isolated hepatocytes were examined following treatment of sheep with glucagon or saline. Glucagon or sterile saline was infused at 9·8 µg/min for 3 h into the jugular vein and then the caudal lobe of the liver was removed surgically under anaesthesia. The caudal lobe was used either to prepare hepatocytes or in a non-recirculating perfusion experiment. Uptake and metabolism of propionate were studied using [2-14C]propionate. In studies using the non-recirculation perfusion of the caudal lobe of the sheep liver it was shown that the treatment of sheep with glucagon resulted in an increased rate of gluconeogenesis from propionate and in an increased net uptake of propionate by the caudal lobe. The uptake of propionate into the hepatocytes was saturable, concentrative and exhibited a Kmfor propionate of 0·24 (SE 0·07) mM and a maximal rate of uptake (Vmax) of 6·7 (SE 0·6) nmol/mg dry cells per min and was unaffected by glucagon treatment of sheep. After incubation of cells in medium containing 0·5 mM-[2-14C]propionate for 10 min, the rate of gluconeogenesis from propionate was 22 % higher in the hepatocytes isolated from glucagon-treated sheep. Concentrations in the medium of 1·35 mM butyrate and 1 mM-caproate inhibited propionate uptake by about 50 % and abolished the glucagon-induced stimulation of gluconeogenesis from propionate. The results are consistent with a regulatory role for glucagon in the gluconeogenesis from propionate in the sheep liver.
Metabolic responses to isoenergetic meals containing different proportions of carbohydrate and fat
Authors: Whitley Helena A. , Humphreys Sandy M. , Samra Jaswinder S. , Campbell Iain T. , Maclaren Donald P. M. , Reilly Tom , Frayn Keith N.
Published: September 2005

The purpose of the present study was to investigate the interrelationship between carbohydrate and fat metabolism at rest after isoenergetic meals of varying proportions of carbohydrate and fat. Eight physically-active subjects (BMI 18·1–23·4 kg/m2) were studied at rest on three occasions after an overnight fast. In a balanced design they were given meals containing carbohydrate, protein and fat in the following amounts respectively (g/70 kg body weight): meal 1 121,16,48; meal 2 70,16,70; meal 3 50, 14, 80. All meals were isoenergetic, containing 4·0 MJ/70 kg body weight, and were of similar appearance. In addition, on a fourth occasion five of the eight subjects consumed meal 4 (g/70 kg body weight): Carbohydrate 0, protein 0, fat 108. Blood samples were taken before eating the meal and at intervals following the meal to determine metabolic and hormonal responses. Energy expenditure and substrate oxidation were measured by indirect calorimetry and balance was calculated over the 5 h postprandial period. The incremental areas under the time curves for fat oxidation were greatest after meals 3 and 4 (P<0·05), whereas incremental areas under thecarbohydrate oxidation v. time curves were relatively reduced after these two meals (P<0·05). This was accompanied by lesser suppression of plasma non-esterified fatty acid concentrations (P<0·001) and reduced plasma insulin concentrations (P<0·001) following these meals. Energy balance was almost identical after the three isoenergetic meals. In contrast, there was an inverse relationship between Carbohydrate and fat balance following these meals, with carbohydrate balance decreasing as carbohydrate intake decreased and fat balance increasing as fat intake increased. We conclude that there is a close interrelationship between carbohydrate and fat metabolism following isoenergetic meals in resting subjects.
Pancreatic enzyme secretion in response to test meals differing in the quality of dietary fat (olive and sunflowerseed oils) in human subjects
Authors: Yago M. D. , Gonzalez M. V. , Martinez-Victoria E. , Mataix J. , Medrano J. , Calpena R. , Perez M. T. , Mañas M.
Published: September 2005

The aim of the present study was to investigate in human subjects whether or not the ingestion of two liquid meals that differed only in their fatty acid composition (due to the addition of olive oil (group O) or sunflowerseed oil (group S) as the source of dietary fat) would lead to differences in the pancreatic enzyme activities secreted into the duodenum. The experiments were performed in eighteen cholecystectomized subjects who, during the 30d period immediately before surgery, modified their habitual diets in such a way that their fat composition would reflect, as far as possible, that of the experimental meals. Lipase (EC3.1.1.3), colipase, amylase (EC3.2.1.1), chymotrypsin (EC3.4.21.1) and trypsin (EC3.4.21.4) activities were measured in duodenal contents aspirated before and after the ingestion of the test meals. The plasma levels of secretin and cholecystokinin (CCK) were also examined. Duodenal enzyme activities were similar in resting conditions. No significant differences were revealed in postprandial enzyme activities, except for lipase activity, which was higher in group O, probably in relation to the greater plasma CCK concentrations observed in this group. In the absence of enzyme output data, we should not exclude the possibility that the type of dietary fat will affect human pancreatic enzyme secretion to a greater extent than is evident from the present study, for instance through a flow-mediated effect, as we previously observed in dogs.
Effect of black tea drinking on blood lipids, blood pressure and aspects of bowel habit
Authors: Bingham S. A. , Vorster H. , Jerling J. C. , Magee E. , Mulligan A. , Runswick S. A. , Cummings J. H.
Published: September 2005

Thirty-one men (47 (SD 14) years) and thirty-four women (35 (SD 13) years) took part in a 4-week randomized cross-over trial to compare the effect of six mugs of black tea daily v. placebo (water, caffeine, milk and sugar) on blood lipids, bowel habit and blood pressure, measured during a run-in period and at the end of weeks 2, 3 and 4 of the test periods. Compliance was established by adding a known amount of p–aminobenzoic acid (PABA) to selected tea bags, and then measuring its excretion in urine. Mean serum cholesterol values during run-in, placebo and on tea drinking were 5·67 (SD 1·05), 5·76 (SD 1·11) and 5·69 (SD 1·09)mmol/l (P=0·16). There were also no significant changes in diet, LDL-cholesterol, HDL-cholesterol, triacylglycerols, and blood pressure in the tea intervention period compared with placebo. Compared with placebo, stool consistency was softened with tea (P=0·04), and no other differences were found in bowel habit. Results were unchanged when fifteen ‘non-compliers’, whose PABA excretion indicated that fewer than six tea bags had been used, were excluded from the analysis, and when differences between run-in and tea periods were considered separately for those who were given tea first or second.
Current diet does not relate to bone mineral density after the menopause
Authors: Earnshaw Steven A , Worley Ann , Hosking David J ,   Nottingham Early PostMenopausal Intervention Cohort (EPIC) Study Group
Published: September 2005

The influence of dietary Ca on peak bone mass and on subsequent bone loss is controversial. Despite this an assessment of nutritional status is often included in the clinical evaluation of osteoporosis risk. To assess the value of this we investigated the relationship between current diet and bone mineral density (BMD) in 426 postmenopausal women, aged 45–59 years, who were enrolled into an international multi-centre trial of alendronate for the prevention of postmenopausal osteoporosis. BMD of the lumbar spine and proximal femur was measured on two occasions approximately 2 weeks apart by dual-energy X-ray absorptiometry. Serum osteocalcin was measured by immunoradiometric assay and serum 25-hydroxycholecalciferol by radioimmunoassay. Dietary assessment was performed by analysis of a 3d unweighed dietary record, using Salford University's Microdiet software. BMD at both the lumbar spine and femoral neck correlated significantly with BMI, age, and average serum osteocalcin concentration. We therefore corrected for these variables in subsequent analyses. Dietary Ca intake ranged from 223 to 2197mg/d (median 852mg/d). Neither dietary Ca intake nor any other nutritional variable correlated significantly with BMD. There was a weak, but significant correlation between Ca intake and serum osteocalcin. We conclude that current diet does not correlate with BMD in early postmenopausal women. However, present diet may affect the rate of change of BMD, and this is supported by the finding of a significant relationship between dietary Ca and serum osteocalcin, a marker of bone formation rate.
Nitrogen balance in adult female mink (Mustela vison) in response to normal feeding andshort-term fasting
Authors: Tauson Anne-Helene , Elnif Jan , Wamberg Søren
Published: September 2005

Ten adult female mink (Mustela vison) were studied in a 7 d balance experiment consisting of a 2 d pre-surgery feeding period, followed by surgery, 1 d of recovery, 4 d ofad libitumfeeding, and a 2d fasting period. In this experiment (Expt A) the animals had osmoticpumps implanted for continuous release of radioactively-labelledp–aminohippuric acid (p–aminobenzoyl-2-[3H]glycine; [3H]PAH;n10) and14C-labelled inulin ([14C]IN;n5). Repeated 24 h collections of urine, corrected to 100%[3H]PAH or [14C]IN recovery, were used for accurate determination of N balances, 24 h urinary excretion of urea, creatinine, and total N, and calculation of mean 24 h renal clearance rates for endogenous creatinine and inulin. N balances were slightly below zero, but not significantly different between feeding and fasting periods, indicating that correction to 100% [3H]PAH recovery resulted in slight overestimation of thefinal balances. During fasting, withdrawal of the dietary water and protein loads resulted in a dramatic decline in 24 h urinary volume, and urea and creatinine excretion. Large individualvariations in 24h urinary creatinine excretion (with relative variation coefficients up to 30%) confirmed that this is an unreliable index of the completeness of urine collection. In this respect, recovery rates of [3H]PAH proved far more consistent. Renal clearance values obtained in fed mink were in fair agreement with published data from cats, dogs and ferrets (Mustela putorius furo). Inulin clearance was about 30% higher than endogenous creatinine clearance, although its decline in response to fasting was not significant. In a separate study (Expt B)another ten female mink were equipped with osmotic pumps containing [3H]PAH for determination of 24 h excretion rates of purine derivatives. During feeding, allantoin accounted for more than 97 % of the excretion of purine derivatives in urine, uric acid making up less than 2·5%, xanthine and hypoxanthine less than 1 %. In fasted animals, urinary excretion of each of these purine derivatives declined to less than 50% of the feeding value. In conclusion, an experimental technique is presented for efficient and accurate measurements of daily urinary excretion of nitrogenous constituents, which allows for correct determination of N balances in adult mink and, presumably, in other mammalian species.
Effects of experimentally-impaired reticular contractions on digesta passage in sheep
Authors: Kaske M , Midasch A
Published: September 2005

The aim of the study was to evaluate the functional role of reticular contractions for digesta passage in sheep. Feed intake, mean retention time of fluid and plastic particles in the reticulo-rumen, rumen fluid volume, forestomach motility and particle size distribution in the faeces were determined in five rumen-fistulated sheep fed on hayad libitum(Expt 1). The same variables were determined when reticular movements were impaired for 10 d by introducing a silicone-covered lead weight (500 g) into the reticulum (Expt 2). As feed intake dropped in Expt 2 by 27% compared with Expt 1, the sheep received in an additional experiment exactly the amount of feed which had been consumed during Expt 2 and measurements were repeated without impairing reticular movements (Expt 3). The introduction of the weight did not affect the frequency of A- or B-cycles, but elevation of the reticular floor in a cranio-dorsal direction during the biphasic contraction was markedly reduced. The pattern of marker excretion indicated a drastically changed composition of reticular outflow in Expt 2 compared with Expts 1 and 3. During Expt 2, rumen fluid volume was similar to that in Expt 1 but about 25% higher than that in Expt 3; the amount of large feed particles in the faeces was increased compared with Expt 1 ( + 49%) and Expt 3 ( + 76%). In at least two sheep, abomasal emptying was inhibited during Expt 2, as indicated by an enlarged impacted abomasum. In conclusion, the results emphasize the central role of reticular motility for the separation of particles in the forestomach, the outflow of digesta from the reticulo-rumen and transpyloric digesta flow.
Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in young chicks
Authors: Edwards III Hardy M , Baker David H , Fernandez Sergio R , Parsons Carl M
Published: September 2005

Broiler chicks were fed on chemically-defined crystalline amino acid diets containing graded levels of L-threonine (Thr) during the period 10–20 d post-hatching. Doses of Thr represented 5,10,15,40,55,70 and 95% of its ideal level for maximal weight gain and feed efficiency. Other amino acids were maintained at minimized excess levels that were 15% (of ideal) above the various doses of Thr. Following 10d of feeding and a 24h fast, chicks were killed for whole-body protein and amino acid analysis. Using pen accretion means, weight gain (r20·98), protein accretion (r2 0·99), and Thr accretion (r2 0·99) were linear (P<0·01) functions of Thr intake. Slope of the Thr accretion regression line indicated that 82% of the Thr intake was recovered in whole-body protein. At zero Thr intake, chicks lost 11·9 mg Thr/d. The Thr maintenance requirement was 45·7 mg/d per kg body weight 0·75. Increasing doses of Thr resulted in increased (P<0·05) concentrations of methionine, isoleucine, histidine and lysine in whole-body protein. Other indispensable amino acids, including Thr, also tended to increase. Whole-body glycine, proline, serine and cystine concentrations decreased (P<0·05) as Thr was increased in the diet. The maintenance need for Thr represented 5·5% of the total need for Thr. The data suggest that efficiency of Thr utilization is constant at all levels of Thr intake between 5 and 95% of the level required for maximal weight gain and feed efficiency.