bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative effects on blood lipids and faecal steroids of five legume species incorporated into a semi-purified, hypercholesterolaemic rat diet
Authors: Dabai Fatima D , Walker Ann F , Sambrook Ian E , Welch Vernon A , Owen Robert W , Abeyasekera Savitri
Published: September 2005

The cholesterolaemic effects in rats of a diet (VS) containing Bambara groundnuts (Vignu subterrunea), a popular legume eaten in Nigeria, were compared with diets PV, PS, LC and PL, containing baked beans (Phaseolus vulgaris), marrowfat peas (Pisum sativum), lentils (Lens culinaris Medik.) and butter beans (Phaseolus lunatus) respectively. Sixty Sprague-Dawley rats were fed on hypercholesterolaemic semi-purified diets supplemented with 10 g cholesterol and 5 g cholic acid/kg and formulated to provide 40% of energy from fat, as in a typical Western-type human diet. Legumes were substituted for 330 g/kg of the semi-purified diet on a dry-matter basis, which was modified to maintain the same contribution of energy sources as the control diet C3. Another ten rats were fed on control diet C2, which was similar to diet C3 but with no added cholesterol. The rats were fed for 8 weeks and plasma cholesterol levels were measured at weeks 4 and 8. The diets incorporating the five different legume species produced very Merent cholesterolaemic effects. Diets PV and PL were more potent at lowering raised plasma cholesterol levels than diets PS and LC. Inclusion of the Bambara groundnut into the semi-purified diet resulted in an exaggeration of hypercholesterolaemia. Differences in cholesterol-lowering capacity of the various legume diets in this experiment could not be related to concentrations of faecal bile acids or neutral sterols. However, there was evidence that the inclusion of legumes in the diets reduced the faecal excretion of secondary bile acids
Carry-over effects of dietary crude protein and triiodothyronine (T3) inbroiler chickens
Authors: Rosebrough R. W , Mitchell A. D , Mcmurtry J. P
Published: September 2005

Indian River male broiler chickens growing from 7 to 30 d of age were fed on diets containing crude protein levels ranging from 120 to 3041 g/kg plus 0 or 1 mg triiodothyronine (T3/)kg diet. The purpose of this study was to examine the effects of these treatments on lipogenesis after a common diet was fed (180 g crude protein/kg diet from 30 to 56 d of age). Dietary treatment groups were sampled at 30 and 56 d.In vitrolipogenesis was determined by incubating liver explants for 2h at 37°in Hanks' salts containing 25 mM-HEPES and 10 mM-[2-14C]acetate and then measuring acetate incorporation into total lipid. Growth and feedconsumption from 7 to 30 d increased (P<0·01) as dietary protein increased from 120 to 210 g/kg diet. Both measurements decreased as crude protein increased from 210 to 300 g/kg diet.T, decreased (P<0·01) growth and feed intake during this period.Low-protein (<180 g/kg) diets increased (P<0·05) and T3, decreased lipogenesis in 30-d-old chickens. Although birds given T3from 7 to 30 dgrew at the greatest rate from 30 to 56 d of age, the final body weight was still less than controls.In vifm lipogenesis at 56 d of age was not affected by either of the two dietary treatments. In contrast, the relative size of the abdominal fat pad (g/kg body weight) at 56 d was decreased by feeding T3from 7 to 30 d. Any changes in metabolism elicited by either dietary protein levels or hormone treatments may be specific to the particular dosing interval and are not sustained when acommon diet is fed during a repletion period.
Maternal undernutrition during late pregnancy in sheep. Its relationship to maternal condition, gestation length, hepatic physiology and glucose metabolism
Authors: West Hilary J.
Published: September 2005

There is a paucity of information on the metabolic effects of undernutrition of the ewe carrying multiple fetuses in late pregnancy. In the present study the effects of induction of ketosis from 132 d gestation in ewes carrying twin fetuses were compared with a control group. The ewes were well fed up to 132 d. Ketotic ewes showed a loss of condition score from 3·7 (SE 0·11) at 130 d gestation to 3·0 (SE 0·15) 10 d later after clinical recovery, compared with control twin-pregnant ewes (P < 0·01). The weight loss during the same time period was from 70·6 (SE 2·7) kg at 130 d to 64·2 (SE 2·7) kg at 140 d gestation. As expected, both groups lost weight and condition score in the first 28 d of lactation. Induction of ketosis caused a significant shortening of the gestation period to 142·8 (SE 0·7) d compared with 150 (SE 0·4) d in normal twin-pregnant ewes (P < 0·001). Ewes with induced ketosis recovered clinically and showed a normal feed intake by 3·4 (SE 0·07) d; three required treatment. Induction of ketosis resulted in reduction of hepatic uptake of bromosulphthalein (P < 0·01) and its biliary excretion (P < 0·05), metabolic clearance rate (P < 0·001), fractional clearance (P < 0·001) and 15 and 30 min retention compared with control twin-pregnant ewes. Most values had returned to normal by the first week of lactation. It is thought that in human pregnancy similar changes in bromosulphthalein clearance may be related to reduced binding sites for bromosulphthalein in the liver caused by increased circulating oestrogens. Induction of ketosis resulted in a significant hypoglycaemic (P < 0·01), ketotic (P < 0·001) state compared with well-fed twin-pregnant ewes. These changes could be correlated with the severity of the clinical signs, together with a significant rise in plasma urea (P < 0·001) and NH3(P < 0·05) concentrations. Again, the return of most of these values to normal by the first week of lactation lends support to the reversibility of hepatic lesions caused by fatty infiltration of the liver. The seventy of this condition in naturally occurring cases suggests that factors other than undernutrition may be contributory, such as the general body condition of the ewe and glucose metabolism by the liver, including the conversion of propionate to glucose.
Zinc absorption in adult humans: the effect of protein sources added to liquid test meals
Authors: Davidsson Lena , Almgren Annette , SandströM Brittmarie , Juillerat Marc El-A , Hurrell Richard F
Published: September 2005

The influence of different protein sources on Zn absorption was evaluated in healthy adults by radioisotopic labelling of single meals, followed by whole-body retention measurements 14 d after intake. Semi-synthetic liquid diets were used for the evaluation of different animal-protein sources and dephytinized soyabean-protein isolate ( ··01 g phytic acid/kg). Zn absorption was measured in the same subjects from identical test meals containing no added protein. No statistically significant differences were found in the Zn absorption from test meals containing bovine whey, casein or egg albumen when compared with test meals without added protein. Bovine serum albumin (BSA) and soyabean-protein isolate (< ··01 g phytic acid/kg) significantly reduced the mean absorption of Zn from 45–49% (no added protein) to 38·0 (SD 10·9) (BSA, P < ··05) and 33·9 (SD 12·6)% (soyabean-protein isolate < ··01 g phytic acid/kg, P < ··01). These results demonstrate that Zn absorption is inhibited by certain protein sources, such as BSA and dephytinized soyabean-protein isolate, while other proteins have little or no effect.
Streptozotocin-induced diabetes in rats is associated with impaired metabolic availability of vitamin A (retinol)
Authors: Tuitoek P. J. , Ziari S. , Tsin A. T. C. , Rajotte R. V. , Suh Miyoung , Basu* Tapan K.
Published: September 2005

Using streptozotocin-induced diabetic Wistar rats, studies were carried out to examine the metabolic availability of vitamin A in the plasma, liver and the retina of the eye. Control and diabetic rats were fedad lib. on a semi-purified diet either with or without (basal) vitamin A supplementation, or pair-fed on the basal diet for 4 weeks. Despite the fact that diabeticrats consumed 48% more feed, they had lower plasma concentrations of retinol (P<0·003). The decrease in plasma retinol concentration was a response to diabetes (or diabetes-induced trauma), since neither pair-feeding (P<0·01) nor vitamin A supplementation altered this effect (P<0·05). Furthermore, the hepatic concentrations of the vitamin in these animals remained elevated and this increase was greater in the supplemented diabetic group (P<0·001). Decreases in 11-cis retinal (a component of rhodopsin) concentrations in the retina were also observed in diabetic animals. The increased hepatic and the decreased plasma and retina vitamin Alevels suggest a defect in the transport of the vitamin from the liver.
Supplemental vitamin A enhances the recovery from iron deficiency in rats with chronic vitamin A deficiency
Authors: Roodenburg AnnetJ.C , West Clive E , Hovenierl Robert , Beynen Anton C
Published: September 2005

Studies with anaemic children and pregnant women from areas where vitamin A deficiency is endemic have shown a beneficial effect on Fe status of supplemental vitamin A in addition to Fe supplementation. This suggests a relationship between vitamin Aand Fe status, which we attempted to mimic in rats with anaemia and chronic vitaminA deficiency. Male rats were fed on Fe-adequate diets (35 mg Fe/kg)containing different levels of vitamin A (1200,450,150,75 and 0 retinol equivalents (RE)/kg feed) until they were 5 weeks old. These diets wereidentical to the diets fed to their mothers. Then the young male rats were transferred to diets containing the same levels of vitamin A but no added Fe. After another 2 weeks the rats wererepleted with Fe (35 mg/kg feed) without or with vitamin A to a level of 1200 RE/kg feed. Increased vitamin A intake by the groups previously fed on diets with either 0 or 75 RE/kg produced a reduction in blood haemoglobin concentration, packed cell volume and erythrocyte count. In the group which had been fed on the diet without vitamin A, supplemental vitamin A raised mean cell volume, plasma Fe concentration and total Fe-binding capacity. Vitamin A supplementation during the period of Fe repletion produceda decrease in splenic and tibia Fe concentration, the effect being greater with increasing seventy of previous vitamin A deficiency. The paradoxical effect of supplemental vitamin A on haemoglobin, packed cell volume and erythrocyte count can be explained by a decrease in the degree of haemwoncentration. Thus, the positive effect of supplemental vitamin A seen in humans is also observed with rats under controlled experimental conditions. We speculate that supplemental vitamin A during Fe repletion contributes to optimum erythropoiesis and Fe mobilization when baseline vitamin A status is impaired
Changes in vitamin-D metabolites and parathyroid hormone in plasma following cholecalciferol administration to pre- and postmenopausal women in the Netherlands in early spring and to postmenopausal women in Curaçao
Authors: Van Der Klis Fiona R. M. , Jonxis Jan H. P. , Van Doormaal Jasper J. , Sikkens Peter , Saleh Alejandro E. C. , Muskiet Frits A. J.
Published: September 2005

To study the effect on plasma 25-hydroxycholecalciferol (25(OH)D), 1,25-dihydroxycholecalciferol (1,25(OH)2D) and parathyroid hormone (PTH) we supplemented premenopausal (aged 30 (SD 7) years) and postmenopausal (aged 61 (SD 2) years) white women living in The Netherlands in late winter/early spring, and elderly black and white women (aged 75 (SD 6) years) living in Curacao (Dutch Antilles) with either 10 or 20µpg cholecalciferol/d for 4, 5 and 9 weeks respectively. Baseline plasma 25(OH)D concentration of Dutch women was lower than that of Curacao women. Postmenopausal Dutch women had a higher PTH concentration in plasma than premenopausal Dutch and postmenopausal Curaçao women. There were no differences in plasma 1,25(OH)2D. Cholecalciferol administration increased 25(OH)D in all groups, 1,25(OH)2D in postmenopausal Curaçao women and PTH in postmenopausal Curaçao women and premenopausal Dutch women. Serum and urinary Ca and phosphate concentrations did not change. There were no response differences between 10 and 20 µg doses. Oral cholecalciferol administration (either 10 or 20 µg/d) to women living at northern latitudes in late winter/early spring increased 25(OH)D levels to the baseline levels of elderly people living in the tropics.
Unexpected relationship between fat mass and basal metabolic rate in pregnant women
Authors: Bronstein Michele N. , Mak Rosa P. , King* Janet C.
Published: September 2005

We investigated the relationships between BMR, fat-free mass (FFM) and fat mass in pregnancy. BMR was measured by indirect calorimetry and body composition was assessed by densitometry in seventeen non-pregnant women (79·9 (SD 26·3, range 505−151·4) kg) and sixteen pregnant women (75·7 (SD 20·6, range 545−115·9) kg). The pregnant women were evaluated during weeks 31−35 of gestation. Multiple regression analysis of BMR with FFM and fat mass in the non-pregnant women showed that FFM was a highly significant predictor of BMR (P < 0·0001), but fat mass was not (P = 0·09). In contrast, in the pregnant women, multiple regression analysis revealed that fat mass was a highly significant predictor (P < 0·001), while FFM was not (P = 0·69). Evaluation of the interaction terms in the combined data set confirmed that the relationships of BMR with FFM and fat mass differ significantly in non-pregnant and pregnant women. It is proposed that pregnancy represents a unique condition during which BMR is regulated by maternal adipose reserves. An augmented BMR in overweight pregnant women may be protective, given that excessive weight gain may be detrimental to neonatal and maternal health.
Determination of rumen microbial-nitrogen production in sheep: a comparison of urinary purine excretion with methods using 15N and purine bases as markers of microbial-nitrogen entering the duodenum
Authors: erez J. F. , Balcells J. , Guada J. A. , Castrillo C.
Published: September 2005

The present study compares estimates of rumen microbial-N production derived from duodenal flow measurements (15N and purine bases) with those from measurements of the urinary excretion of purine derivatives. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Four diets consisting of 550 g lucerne (Medicago sativa) hay/d as sole feed or supplemented with 220, 400 and 550 g rolled barley grain/d were given in a 4 x 4 random factorial arrangement. Duodenal digesta flows were determined by the dual-phase marker technique during continuous intraruminal infusions of Co-EDTA and Yb-acetate. Microbial contribution to the non-NH3N (NAN)flow was estimated from 15N enrichment and purines: N ratio in duodenal digesta and bacterial fractions isolated from the rumen content. Whole tract organic matter (OM) digestibility and duodenal flow of OM and NAN increased (P<0·001) with the level of barley supplementation. Digestible OM intake ranged from 19·0 to 42·7 g/kg metabolic weight (W0·75) and the duodenal flow of purine bases and the urinary excretion of allantoin increased Linearly (P < 0·001) from minimum values of 7·47 (SD 1·524)and 4·65 (SD 0·705) mmol/d respectively on the basal diet to 18·20 (SD 1·751) and 11·62 (SD 0·214) mmol/d on the 400 g barley diet; a further increase in barley supplementation decreased both variables (13/50 (SD 2/334) and 8/77 (SD 0/617) mmol/d respectively). Urinary excretion of uric acid and hypoxanthine showed a slight but significant increase (P < 0·05) over all levels of barley. Molar recoveries of duodenal purine bases as purine derivatives or allantoin in the urine were 0·78 (SD 0·156) and 0·65 (SD 0·130) respectively. The increase on barley supplementation significantly augmented microbial-N, but large differences between microbial markers employed were observed. Mean values of microbial-N estimated from the duodenal purine bases or urinary allantoin excretion were on average 18 and 29% lower than those measured by 15N.
Dietary fat influences Ia antigen expression, cytokines and prostaglandin E2production of immune cells in autoimmune-prone NZB x NZW F1 mice
Authors: lin Bi-Fong , Huang Chao-Chi , Chiang Bor-Luen , Jeng Su-Jen
Published: September 2005

Abstracts

To elucidate further the influences of dietary fat on autoimmune diseases, two groups of NZB/W F1 mice were fed with diets containing 200 g dietary fat/kg and 50 g dietary fat/kg (control) respectively. The difference in energy intake between these two groups was compensated with carbohydrate. Mice were bled regularly every month and some of them were killed forin vitroexperiments after 5 months experimental diets. Higher immunoglobulin (Ig)M and IgG anti-double stranded DNA antibody levels, shortened life span and worsened proteinuria were noted in mice fed on the high-fat diet compared with those fed on 50g dietary fat/kg. Phenotypic analyses of spleen cells and peritoneal exudate cells showed that the percentage of CD5+B cells and the mean fluorescent intensity of major histocompatibility molecules on the surface of both types of cells were higher in mice fed on the high-fat diet. In general, higher type 2 T-helper cell activity was noted in mice fed on the high-fat diet. In addition, cytokines such as interleukin-6, tumour necrosis factor-α and prostaglandin E2(PGE2) produced by lipopolysaccharide-stimulated peritoneal exudate cells were also higher in the high-dietary-fat group. These studies suggest that high dietary fat and its related PGE2level might have a critical effect on the frequency of CD5+B cells, cytokine production, macrophage function and subsequent autoimmune regulation in autoimmune mice.
Digestion and physiological properties of resistant starch in the human large bowel
Authors: Cummings John H , Beatty Emily R , Kingman Susan M , Bingham Sheila A , Englyst Hans N
Published: September 2005

The digestion of four sources of resistant starch (RS) has been studied in twelve healthy volunteers who ate controlled diets for 15 d periods. RS from potato, banana, wheat and maize (17−30 g/d) was compared with a starch-free diet, a diet containing wheat starch that was fully digested in the small intestine, and with 18·4 g NSP from bran/d. RS increased stool wet weight by 1·6 g/d per g RS fed for potato, 1·7 for banana, 2·5 for wheat and 2·7 for maize, but this was significantly less than bran NSP at 4·9 g/g. RS was extensively digested in twenty-seven of thirtyfour diet periods but five subjects were unable to break down one or two of the RS sources. Faecal N and energy excretion were increased. RS decreased NSP breakdown and RS2(resistant starch granules) tended to prolong transit time. All forms of RS increased faecal total short-chain fatty acid excretion. RS2(from potato and banana) gave greater proportions of acetate in faeces, and RS3(retrograded starch from wheat and maize) more propionate. We have concluded that RS2and RS3are broken down in the human gut, probably in the colon although in 26% of cases this breakdown was impaired. RS exerts mild laxative properties, predominantly through stimulation of biomass excretion but also through some sparing of NSP breakdown.
Measurement of resistant starch in vitro and in vivo
Authors: Englyst Hans N. , Kingman Susan M. , Hudson Geoffrey J. , Cummings John H.
Published: September 2005

The digestibility of the starch in plant foods is highly variable, and is dependent on a number of factors, including the physical structure of both the starch and the food matrix. An in vitro technique has been developed to categorize starch in plant foods according to its likely rate and extent of digestion in the human small intestine. The in vitro method provides values for rapidly digestible starch, slowly digestible starch and resistant starch (RS). In the present study values for the RS content of foods, as measured by the analytical technique, were compared with the recovery of starch from these foods when fed to healthy ileostomates. Nine ileostomy subjects were given a polysaccharide-free diet with a breakfast supplement, on each of 2 d (two subjects) or 3 d (seven subjects), of biscuits made from wheat, potato or banana flours or from moist-heat-processed wheat or maize flours. RS intakes measured in vifro ranged from 8·5 to 15·0 g/d for the test biscuits, and mean starch recoveries in ileostomy effluent were 100·4 (n5, range 91−106)% of those values, but there was substantial variation between individuals. It is proposed that RS is defined as ‘the sum of starch and starch-degradation products that, on average, reach the human large intestine’. The analytical method for the measurement of RS in vitro based on this definition is shown to provide an accurate prediction of the average amount of starch that is likely to escape complete digestion and absorption in the human small intestine.
Fermentable carbohydrate modulates postprandial enteroglucagon and gastrin release in rats
Authors: Gee J. M. , Lee-Finglas W. , Johnson I. T.
Published: September 2005

We studied the effects of a fermentable sugar-alcohol (lactitol) on the concentrations of enteroglucagon and gastrin in the blood of rats for 7·5 h after feeding. The control and treatment groups were fed on semi-purified diets containing either non-fermentable cellulose or lactitol respectively, at 100 g/kg. Compared with the cellulose-fed group, the animals fed with lactitol had higher levels of enteroglucagon (5−10 times higher than control; P < 0·05) and lower serum gastrin (70−80% of control; P< 0.·05) for several hours after the withdrawal of feed. In contrast, varying the level of dietary lipid (maize oil) over a range of 8−120 g/kg had no effect on the release of either peptide. These results suggest that poorly absorbed fermentable dietary carbohydrate stimulates postprandial plasma enteroglucagon and inhibits serum gastrin release in the rat. The mechanism is uncertain but an endocrine response by the colon to fermentation products seems probable.
Lipid fluidity of triacylglycerol-rich lipoproteins isolated from copper-deficient rats
Authors: Motta Claude , Gueux Elyett , Mazur Andrzej , Rayssiguier Yves
Published: September 2005

Triacylglycerol-rich lipoproteins (TGRLP) were isolated from Cu-deficient and control rats. TGRLP from Cu-deficient rats appeared more fluid than those from controls as sensed by the fluorescence anisotropy of 1,6-diphenyl-l-3,5-hexatriene (DPH). This high fluidity was related to alow cholesterol: phospholipid ratio and high triacylglycerol content in these lipoproteins. TGRLP from Cu-deficient rats were more susceptible toin vitroperoxidation than lipoproteins from control rats as shown by the rate of diene conjugation. The damage induced by the peroxidation resulted in a more ordered state of the lipid fraction especially in lipoproteins from Cu-deficient rats. Thus, afterin vitroperoxidation, TGRLP from Cu-deficient rats were more rigid than those from controls. These results suggest that Cu deficiency induces modifications in physicochemical properties of TGRLP which could affect their metabolism.
Prevention of coprophagy modifies magnesium absorption in rats fed with fructo-oligosaccharides
Authors: Ohta Atsutane , Baba Seigo , Ohtsuki Masako , Taguchi Adusa , Adachi Takashi , Hara Hiroshi
Published: September 2005

Abstracts

We developed a new type of anal cup for prevention of coprophagy and determined whether the absorption of Ca and Mg and the stimulatory effects of feeding fructo-oligosaccharides (FO) on theabsorption of Ca and Mg were altered by prevention of coprophagy in rats. Rats were fed on a FO-free diet or a diet containing 50 g FO/kg for 2 weeks with or without prevention of coprophagy. FO-feeding increased the apparent absorptive ratio of Ca and Mg in rats with or without prevention of coprophagy. However, in the FO-fed groups the absorptive ratio of Mg in rats with prevention of coprophagy was higher than in rats withont prevention of coprophagy. The Ca content of the femur was higher in rats fed on the FO-diet than in rats fed on the FO-free diet both with and without coprophagy. In conclusion, FO-feeding increased the absorption of Ca and Mg in rats both with and without coprophagy. Moreover, prevention of coprophagy enhanced the absorption of Mg in rats fed with FO. Coprophagy has to be considered when the effects of luminal fermentation or mineral absorption are examined in rats
Conjunctival impression cytology with transfer (CICT) to detect pre-clinical vitamin A deficiency among slum children in India
Authors: Chowdhury Swapan , Kumar Rajesh , Ganguly N. K. , Kumar Lata , Nain C. K. , Walia B. N. S.
Published: September 2005

In order to establish a method usable in the field for diagnosis of pre-clinical vitamin A deficiency, conjunctival impression cytology with transfer (CICT) was used in 200normal slum children aged 6−120 months in Chandigarh, India. Conjunctival impressions taken on cellulose acetate paper were transferred to glass slides which were fixed in ethanol and stained with alcian blue and carbol fuchsin. Sixty samples of cellulose acetate paper were preserved after transfer of impression and were stained later. Transfer was complete in forty-eight samples and in the other twelve it was incomplete. Conjunctival impressions on paper and slide of these twelve cases were comparable. At a plasma retinol concentration of <0·70 pmol/l measured by HPLC the sensitivity, specificity and positive predictive values of CICT were 90·5%, 100% and 100% respectively. Compared with conventional conjunctival impression cytology, CICT is less time consuming, cheaper and comparable in validity. It is thus more suitable than the conventional method for mass screening
Body composition assessment in lean and normal-weight young women
Authors: Fogelholm G. Mikael , Kukkonen-Harjula T. Katriina , Sievänen Harri T. , Oja Pekka , Vuori Ilkka M.
Published: September 2005

Using percentage body fat (BF%) from a three-compartment (3C) model (body density from underwater weighing (UWW) and bone-mineral mass from dual-energy X-ray absorptiometry (DXA)) as a criterion, we studied the accuracy of UWW, DXA, two skinfold equations, and two bioimpedance (BIA) equations. Thirty-four women (aged 16–20 years) with BF% 13·5–31·1 volunteered. UWW underestimated BF% by −0·5 BF% (95 % CI: −1·0; −0·02), whereas DXA overestimated it by 7·3 BF% (95% CI5.8;8·8). Skinfolds underestimated and BIA overpredicted BF%. The differences between 3C and UWW, skinfolds (Durnin & Womersley, 1974) and BIA (Deurenberg et al. 1990) were dependent (range of r values: −0.63 to −0.79; P < 0·0001) on BF%, causing an overestimation of lean subjects' (UWW, BIA) or an underestimation of normal-weight subjects' (UWW, skinfolds) BF%. The 3C model and UWW gave comparable body-composition results for healthy young women with BF% of approximately 20–25. Based on a significant mean difference from the 3C model, and a large standard error of the estimate, we do not regard DXA as superior to skinfolds or BIA to assess BF%.
Effect of protein restriction on the messenger RNA contents of bone-matrix proteins, insulin-like growth factors and insulin-like growth factor binding proteins in femur of ovariectomized rats
Authors: Higashi Yusuke , Takenaka Asako , Takahashi Shin-Ichiro , Noguchi Tadashi
Published: September 2005

It has been reported that loss of ovarian oestrogen after menopause or by ovariectomy causes osteoporosis. In order to elucidate the effect of dietary protein restriction on bone metabolism after ovariectomy, we fed ovariectomized young female rats on a casein-based diet (50g/kg diet (protein restriction) or 200g/kg diet (control)) for 3 weeks and measured mRNA contents of bone-matrix proteins such as osteocalcin, osteopontin and α1 type I collagen, insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) in femur. Ovariectomy decreased the weight of fat-free dry bone and increased urinary excretion of pyridinium cross-links significantly, although dietary protein restriction did not affect them. Neither ovariectomy nor protein restriction affected the content of mRNA of osteopontin and osteocalcin; however, ovariectomy increased and protein restriction extensively decreased the α1 type I collagen mRNA content in bone tissues. Ovariectomy increased IGF-I mRNA only in the rats fed on the control diet. Conversely, protein rest riction increased and ovariectomy decreased the IGF-II mRNA content in femur. Furthermore, the contents of IGFBP-2, IGFBP-4 and IGFBP-5 mRNA increased, but the content of IGFBP-3 mRNA decreased in femur of the rats fed on the protein-restricted diet. In particular, ovariectomy decreased the IGFBP-2 mRNA content in the protein-restricted rats and the IGFBP-6 mRNA content in the rats fed on the control diet. These results clearly show that the mRNA for some of the proteins which have been shown to be involved in bone formation are regulated by both quantity of dietary proteins and ovarian hormones.
In vivothreonine oxidation in growing pigs fed on diets with graded levels of threonine
Authors: Floc'h N. Le , Obled C. , Sève B.
Published: September 2005

Threonine oxidation to glycine was investigatedin vivoin twelve growing pigs (27·4 kg live weight) fed on one of the following three diets with graded levels of threonine supply: a low-threonine diet (LT), a control well-balanced diet (C) or a high-threonine diet (HT), during 10h constant infusion of L-[1-13C]threonine and [2-3H]glycine in the cranial vena cava and [l-14C]glycine in the portal vein.13C-threonine and glycine enrichments and [3H]glycine and [14C]glycine specific radioactivities (SR) were determined at plateau in peripheral venous plasma, liver and pancreas. Glycine praduction rates calculated from plasma [2-3H]glycine or [1-14C]glycine SR gave similar values suggesting that [l-14C]glycine SR could be used in order to estimate whole-body glycine flux. The high pancreas [1-13C]glycine enrichment provided evidence that the pancreas may be, with the liver, a major site of threonine oxidation to glycine. Moreover, the present findings suggest that threonine transport into the Liver could be the limiting step of threonine oxidation in this tissue when dietary threonine supply is low. Total threonine oxidation to glycine, calculated from plasma values of enrichment and specific radioactivity, was low and constant when the estimated absorbed threonine was lower than 4 g/d and increased for higher amounts of absorbed threonine.
Dietary lysine deficiency greatly affects muscle and liver protein turnover in growing chickens
Authors: Tesseraud S. , Peresson R. , Lopes J. , Chagneau A.M.
Published: September 2005

We analysed the respective influences of age and lysine deficiency on skeletal muscle and liver protein turnover. Growing male broilers were fed ad libirum on isoenergetic diets containing 2OO g crude protein/kg which varied in their lysine content (7·7 or 10·1 g/kg). Fractional rates of protein synthesis (FSR) were measured in vivo in the liver and the pectoralis major muscle of 2-, 3- and 4-week-old chickens (flooding dose of l-[143H]phenylalanine). Fractional rates of proteolysis (FBR) were estimated for the same tissues as the difference between synthesis and growth. Over the 2-week period liver FSR and FBR were unchanged, whereas muscle FSR decreased with age. This developmental decline was related to the lower capacity for protein synthesis (Cs) without any modifications of the translational efficiency. Whatever the age, lysine deficiency resulted in significant decreases in body weight, tissue protein content and tissue protein deposition, apparently because of reduced amounts of proteins synthesized. We recorded a difference in the response of the two tissues to lysine deficiency, the pectoralis major being more sensitive than the liver. When comparing birds of the same age, liver FSR and FBR were not modified by the diet, where as muscle FSR, Cs and FBR were higher in chicks fed on a lysinc-deficient diet than in the controls. Conversely, when chicks of similar weights were compared, the main effect of the dietary deficiency was an increase in muscle FBR. The results suggest that lysine deficiency not only delayed chick development so that protein turnover was affected, but also induced greater changes in metabolism. Thus, the principal mechanism whereby muscle mass decreased appeared to be a change in FBR.
Intestinal mucin distribution in the germ-free rat and in the heteroxenic rat harbouring a human bacterial flora: effect of inulin in the diet
Authors: Fontaine N. , Meslin J. C. , Lory S. , Andrieux C.
Published: September 2005

A colorimetric method was used on water-soluble much extracted from mucosal scrapings and contents of the caecum and the colon of five germ-free (GF) rats and five heteroxenic (HE) rats harbouring a hnmao flora (GF rats d a t e d with a human flora). These rats were fed on a diet containing either 100 g sucrose/kg or 100 g inulin/kg. Histological stains, periodic acid–Schiff, alcian blue pH 2·5 and alcian blue pH 0·5 were used to discriminate between neutral, acidic and acidic sulphated mucins respectively. Spectrocolorimetric assays led to a calculated absorbance value for 1 mg of the initial much extract. Each much type was compared between treatments. The caecal contents of GF rats contained more acidic mucin than sulphomucin, which was present in the same proportion as neutral mucin. Their colonic contents contained more acidic mucins than sulphomucin, which in turn was more abundant than neutral mucin. Their caecal mucosa mucin distribution differed from that of the contents: very little acidic much was present and neutral and dphomucin proportions were of the same order of magnitude. Inulin increased the amount of neutral much in the caecal contents and of sulphated mucios in the colonic contents and increased the amounts of neutral and acidic mucins in the caecal mucwa. Mucin distribution in the HE rats was very different from that in the GF rats: the caecal contents contained a high proportion of acidic much and very little sulphomucin. The same distribution of mucins was observed in the colonic contents. The caecal mucaw contained less acidic much and more sulphomucin than the caecal contents. Inulin decreased acidic mucins and increased sulphated much in the caecal contents and increased neutral and sulphated mucins in the colonic contents. Inulin increased sulphomucin in the caecal m u m and decreased acidic much in the caecal and colonic mucosas. The very low amount of mucin that was recovered in the colonic mucosa suggests that, in the presence of the bacterial flora and associated with inulin in the diet, much was extensively released from the mucosa to the colonic lumen. This might be related to the bacterial metabolites produced
Interactions in indices of vitamin A, zinc and copper status when these nutrients are fed to rats at adequate and increased levels
Authors: Sundaresan P. R. , Kaup Susan M. , Wiesenfeld Paddy W. , Chirtel Stuart J. , Hight Susan C. , Rader Jeanne I.
Published: September 2005

The purpose of the present study was to determine the effects of feeding nutritionally adequate and increased levels of vitamin A (retinyl acetate at 1·4, 34·4, and 206·4 mg/kg diet) in combination with adequate or increased Zn (12 and 240 mg/kg) and Cu (5 and 50mg/kg) on serum and tissue concentrations of retinol and retinyl palmitate and on indices of Cu and Zn status in female Sprague–Dawley rats, and to measure interactive effects of such nutrient imbalances. Rats fed on diets containing 34·4 and 206·4 mg vitamin A/kg had higher feed intakes and relative Liver weights than those fed on diets containing 1.4mg vitamin A/kg. An interaction between dietary Cu and Zn and an independent effect of vitamin A affected serum ceruloplasmin oxidase (EC 1.16.3.1) activity. Rats fed on high Zn, adequate-Cu diets (240 and 5 mg Zn and Cu/kg respectively) had lower serum ceruloplasmin oxidase levels than rats fed on adequate-Zn, adequate-Cu diets (12 and 5 mg Zn and Cu/kg respectively). This effect was not observed in rats fed on high-Zn, high-Cu diets (240 and 50mg Zn and Cu/kg respectively). Alterations in dietary levels of Cu and vitamin A independently affected haemoglobin levels. Serum cholesterol concentration was affected by interactions between Zn and vitamin A and Cu and vitamin A. Levels of retinol and retinyl palmitate in liver and kidney were significantly higher in rats fed on diets with increased dietary vitamin A than in those fed on diets with adequate vitamin A. Three-way interactions among Cu, Zn, and vitamin A affected levels of retinol in serum and liver. Two-way interactions between Cu and vitamin A affected liver retinyl palmitate and the sum of liver retinol + retinyl palmitate. An independent effect of dietary Zn on these variables was also observed. Interactions between Cu and vitamin A affected levels of Cu in liver and kidney, while Fe and Zn in kidney were affected by interactions between Cu and Zn. This study demonstrates that differing interactions among variables of vitamin A metabolism and mineral status occur with higher dietary levels of vitamin A, Zn and Cu in the rat
Accumulation of methylmalonic acid caused by vitamin B12-deficiency disrupts normal cellular metabolism in rat liver
Authors: Toyoshima Shigeki , Watanabe Fumio , Saido Hisako , Pezacka Ewa H. , Jacobsens Donald W. , Miyatake Kazutaka , Nakano Yoshihisa
Published: September 2005

To clarify the relationship between intracellular concentrations of methylmalonic acid and metabolic and growth inhibition in vitamin B12-deficient rats, hepatic methylmalonic acidlevels were assayed and inhibition of glucose and glutamic acid metabolism by methylmalonic acid was studied in isolated hepatocytes. Vitamin B12-deficient rats (14 weeks old) excreted more urinary methylmalonic acid and had lower body weights than the control rats. Hepatic methylmalonic acid levels (3·6 (SD 1·30)–5·3 (SD 0·51) µmol/g tissue; 7·9 (SD 2·90)–11·8 (SD 1·14) mM) were increased and correlated with the extent of the growth retardation during vitamin B12-deficiency. Isolated hepatocytes and mitochondria from normally fed rats were labelled with [14C(U)]glucose and [14C(U)]glutamic acid respectively, in the presence or absence of 5mM-methylmalonic acid. Although methylmalonic acid did not affect the incorporation of14C into protein and organic acid fractions in the hepatocytes, it inhibited14CO2formation (an index of glucose oxidation by the Krebs cycle) by 25% and incorporation of14C into the amino acid fractionby 30%. In the mitochondria, methylmalonic acid inhibited14CO2, formation (indicating glutamic acid oxidation by the Krebs cycle) by 70%, but not the incorporation of14C into the protein fraction. The incorporation of14C into the organic acid fraction was significantly stimulated by the addition of methylmalonic acid. These results indicate that the unusual accumulation of methylmalonic acid caused by vitamin B12-deficiency disrupts normal glucose and glutamic acid metabolism in rat liver, probably by inhibiting the Krebs cycle.
Vitamin E incorporated into a very-low-fat meal is absorbed from the intestine of young rats
Authors: Brink Elizabeth J. , Haddeman Edward , Tijburg Lilian B. M.
Published: September 2005

Vegetable fats and oils are major sources of dietary vitamin E. Consequently the current trend to reduce fat consumption is accompanied by a reduction of the intake of vitamin E. In addition, the absorption of vitamin E is thought to be dependent on the hydroiysis of dietary lipids in the small intestine. It is therefore conceivable that a lower dietary fat intake also diminishes the intestinal absorption of vitamin E. The present 3-week feeding study in young male rats was designed to investigate whether different concentrations of vitamin E added to a very-low-fat product (0, 330 or 1350mgdl-α-tocopheryl acetate/kg product) were absorbed. We therefore incorporated these products into a very-low-fat meal (final fat concentration: 7 g/kg) or a low-fat meal containing 52 g fat/kg. The magnitude of vitamin E absorption from these meals was compared with that from meals containing similar amounts of vitamin E, but a high fat concentration of 190 g/kg. Apparent vitamin E absorption was defined as intake of α- tocopherol equivalents (αTE) minus faecal αTE excretion over 4 d during week 3 of the experimental period. The results of this study showed that apparent absorption of vitamin E from a very-low-fat meal varied, depending on the vitamin E concentration, from 73 to 83%. The magnitude of this vitamin E absorption was not significantly different from that from meals containing a high amount of fat. Liver vitamin E status was equal in rats fed on the very-low-fat meals compared with those fed on the high- fat meals. We conclude that, when very-low-fat or low-fat products are used as a replacement for full- fat products, addition of vitamin E to these products, asdl-α-tocopheryl acetate, might be useful in meeting the vitamin E requirements.
Energy intakes, anthropometry and body composition of Nigerian adolescent girls: a case study of an institutionalized secondary school in Ibadan
Authors: Cole Abiodun H. , Taiwo Omowumi O. , Nwagbara Ngozi I. , Cole Cornelia E.
Published: September 2005

Twenty-two apparently healthy Nigerian adolescent girls aged 11–17 years residing in a hostel, were studied over five consecutive days in order to assess their energy intake (EI), energy cost of specific activities and body composition (BC). The mean characteristics of the group were: height 1·58 (SD 0·1, range 1·42–1·68) m, body weight 49·1 (SD 7·9, range 34·0–61·0) kg and BMI 19·5 (SD 2·0, range 16·0-23·0) kg/m2. The food intake of each subject was assessed by direct weighing and its energy value was determined by means of a ballistic bomb calorimeter. BMR values were calculated according to Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) (1985) equations. Percentage body fat (BF %) values were derived from three skinfold thickness measurements, using population-specific equations. The adolescents' mean daily EI was found to be 6510 (SD 855) kJ/d (138·3 (SD 27·8) kJ/kg body weight per d) which is lower than the FAO/WHO/UNU (1985) calculated energy requirement of 8800 kJ/d for adolescent girls aged 12–14 years. The contributions of specific nutrients and individual meals to the total EI were: carbohydrate, protein and fat, 59·2, 12·5 and 28·3 % of energy respectively and breakfast, lunch and supper, 21·5, 41·0 and 37·4 % respectively. However, the mean BMR was 5627kJ/d, which is comparable with that given by FAO/WHO/UNU (1985) for adolescent girls aged 13–14 years. The mean BF % was found to be 21·7. The comparatively low EI of the participants in the present study may be indicative of energy deficiency in their meals. This assumption is also reflected in their BC values. Nevertheless, further studies of this kind on adolescents in Nigeria are needed to confirm these observations.
Acute effects of exercise on energy intake and feeding behaviour
Authors: Imbeault Pascal , Saint-Pierre Sylvie , AlméRas Natalie , Tremblay Angelo
Published: September 2005

The main objective of the present study was to evaluate the short-term effects of exercise of different intensities on energy intake. Eleven young men were submitted to three randomly assigned sessions (one control and two exercise sessions) in which they ate, ad libitum, foods from a buffet-type meal. The energy cost of exercise was the same in the two exercise sessions. Results showed that there was no significant change in post-exercise subjective levels of hunger and fullness as well as total energy and macronutrient intakes in comparison with the control session. However, when energy intake relative to expenditure was considered by subtracting the surplus of energy expended during exercise from total energy intake, high-intensity exercise exerted a greater reducing effect on this variable compared with the control and low-intensity exercise sessions. These results suggest that for a given level of energy expenditure, high-intensity exercise favours negative energy balance to a greater extent than low-intensity exercise.
Diurnal trends in responses of blood plasma concentrations of glucose, insulin, and C-peptide following high- and low-fat meals and their relation to fat metabolism in healthy middle-aged volunteers
Authors: Frape David L. , Williams Norman R. , Scriven A. J. , Palmer Christopher R. , O'Sullivan Kathryn , Fletcher Reginald J.
Published: September 2005

An experiment was conducted in twelve healthy middle-aged volunteers, six of each sex, with a mean BMI of 27kg/m2 to detect differences between morning and afternoon in postprandial blood glucose, insulin and C-peptide concentrations. These responses were measured following the consumption of isoenergetic meals that were high or low in fat content, at breakfast and at lunch. Over 4d each subject received the high-carbohydrate (L, 5·5 g mixed fat/meal) and moderately high-fat (M, 33 g mixed fat/meal) breakfasts and lunches, in three combinations (LL, MM, LM), or they fasted at breakfast time and received a moderately high-fat lunch (NM), in three Latin squares. Each evening a standard meal was given. Plasma glucose, insulin and C-peptide responses were greater following L than M meals and within both MM and LL treatments insulin and C-peptide responses were greater following breakfast than following lunch. The incremental C-peptide response to a fatty lunch following a fast at breakfast time (NM) was similar to that to a fatty breakfast, but the incremental insulin response for the same comparison was marginally lower at lunch (P=0·06). The relationship of C-peptide and insulin concentrations was assessed. Plasma glucose response to a fatty lunch was increased by a fatty breakfast. The relationships of these metabolic events with fat metabolism are discussed.
Protein utilization during energy undernutrition in sheep sustained by intragastric infusion: effects of protein infusion level, with or without sub-maintenance amounts of energy from volatile fatty acids, on energy and protein metabolism
Authors: Chowdhury S. A. , Ørskov E. R. , Hovell F. D. DeB. , Scaife J. R. , Mollison G.
Published: September 2005

Utilization of endogenous and exogenous energy for protein accretion during energy undernutrition has been studied. Nine lambs nourished by intragastric infusion were given either progressively increasing or decreasing amounts of casein-N up to 2550 mg/kg metabolic weight (W0·75), with or without 250 kJ/kg W0·75 of volatile fatty acids daily. Energy balance (respiration calorimetry) and N balance were measured. While all experimental animals were in negative energy balance, N balance increased curve-linearly with the increase in casein-N infusion and attained positive N balance. Endogenous energy (presumably body fat) was found to meet the energy needs for protein accretion during energy undernutrition. It is concluded that body fat can be effectively utilized to support lean-tissue growth during energy undernutrition, so that the classical nutritional concept of dietary energy:protein ratio is only meaningful when both endogenous and exogenous energy are considered.