PubMed Health⌕ Search

Biomedical subjects

V Legrand-Defretin

Publications and source records attributed to V Legrand-Defretin.

10 recordsLinked to original sources
PubMed2001

Validation of the doubly-labelled water technique in the domestic dog (Canis familiaris).

We validated doubly-labelled water (DLW) by comparison to indirect calorimetry and food intake-mass balance in eight Labrador dogs (24-32 kg) over 4 d. We used several alternative equations for calculating CO2 production, based on the single- and two-pool models and used two alternative methods for evaluating the elimination constants: two-sample and multiple-sampling. In all cases the DLW technique overestimated the direct estimate of CO2 production. The greatest overestimates occurred with the single-pool model. Using two samples, rather than multiple samples, to derive the elimination constants produced slightly more discrepant results. Discrepancies greatly exceeded the measured analytical precision of the DLW estimates. The higher values with DLW probably occurred because the dogs were extremely active during the 1 h in each 24 spent outside the chamber. Estimates of CO2 production from food intake-mass balance, which include this activity, produced a much closer comparison to DLW (lowest mean discrepancy 0.3 % using the observed group mean dilution space ratio and an assumption that the mass changes reflected changes in hydration for all except one animal). We recommend an equilibration time of 6 h and use of the two-pool model based on the observed population dilution space for future studies of energy demands in dogs of this body mass.

Animals↗
PubMed2000

Maintenance energy requirements and the effect of diet on performance of racing Greyhounds.

OBJECTIVES: To determine maintenance energy requirements and effect of diet on performance of racing Greyhounds. ANIMALS: 7 adult racing Greyhounds. PROCEDURE: Dogs were fed a higher fat and protein (HFP) or a lower fat and protein (LFP) diet for 8 weeks in a crossover design. Dogs were exercised for 15 minutes twice daily in a paddock and raced 500 m twice weekly. Blood gas, hematologic, and serum biochemical analyses were performed before and after racing, and race times were compared at the end of each diet period. RESULTS: Mean race time was significantly shorter (32.81+/-0.65 seconds vs. 33.05+/-0.71 seconds), and mean racing speed over 500 m was significantly faster (15.25+/-0.30 vs. 15.13+/-0.30 m x s(-1)) when dogs were fed the HFP diet than when they were fed the LFP diet. Diet had little or no effect on results of blood gas, hematologic, and serum biochemical analyses, except that Hct was 4% greater before and after racing when the HFP diet was fed than when the LFP diet was fed. Mean SD metabolizable energy intake from weeks 1 through 16 was 155+/-9 kcal x kg(-0.75) x d(-1). CONCLUSIONS AND CLINICAL RELEVANCE: Racing Greyhounds ran faster when fed a diet containing higher fat and protein and lower carbohydrate contents. Their maintenance metabolizable energy requirement was slightly higher than that of moderately active dogs.

Animal Feed↗
PubMed1994

Energy requirements of cats and dogs--what goes wrong?

Obesity, which represents the most common form of malnutrition encountered in small animal practices, is mainly the result of overeating. In other words, the energy intake of the obese animal has exceeded at some stage its energy requirement leading to an excessive storage of fat. To overcome such a phenomenon, it is important to define what are the exact energy requirements of dogs and cats. The daily energy requirement of an animal should correspond to the sum of its normal resting energy expenditure, its thermogenesis, and its energy requirement associated with its physical state. The former is affected by intrinsic factors such as body size, body conformation and body composition as well as by environmental parameters (ambient temperature). The latter is affected by the physiological state of the animal (growth, gestation/lactation, ageing) and/or by the amount and type of its activity. The effects of all these factors on the individual energy requirements of dogs and cats will be reviewed here. More scientific information on energy requirements of dogs and cats is clearly necessary to avoid problems of over-or under-feeding. However, there will still be situations where animals become obese because the total energy intake is underestimated. For example, owners often forget to take into account the energy contribution of food eaten outside the regular feeding time. These situations will be discussed because of their importance in the incidence of obesity in pets.

Animals↗
PubMed1993

Metabolism and time-course excretion of murideoxycholic acid, a 6 beta-hydroxylated bile acid, in humans.

The metabolism and time-courses of urinary and fecal excretions of murideoxycholic acid (MDCA; 3 alpha,6 beta-dihydroxy-5 beta-cholanoic acid), a 6 beta-hydroxylated bile acid, was investigated in man. The study was carried out in two groups of subjects. Six cholecystectomized patients fitted with a cystic duct drain ingested 100 mg of a tracer dose of 3H-MDCA. Time-course of radioactivity in plasma was then followed for an 8-h period. Biliary, urinary and fecal excretions of radioactivity were measured for a 5-day period and excreted MDCA metabolites were identified. Five lithiasic patients with intact enterohepatic circulation ingested 500 mg of the same tracer dose of 3H-MDCA. Radioactivity in plasma was followed for a 49-h period and urinary and fecal excretions of radioactivity were measured daily for 7 days. In the first group, the excretion of the radioactivity by the three routes (bile+urine+feces) reached 97.8 +/- 1.5% of the ingested dose but dropped to 75 +/- 8.3% (urine+feces) in patients in the second group. In cholecystectomized patients, the estimation of intestinal MDCA absorption was dependent on cystic duct drain flow rate and gave values ranging from 20% to 87%. The biological half-life of MDCA in lithiasic patients averaged 3.4 +/- 0.7 days. Radioactivity appeared in the plasma in the first hour and reached a maximum 6 and 3 h after the beginning of the experiment in group I and II respectively. In the second group, another peak of radioactivity in plasma was observed just after breakfast.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Ion-pair high-performance liquid chromatography of bile salt conjugates: application to pig bile.

The high-performance liquid chromatographic separation and quantitation of conjugated bile salts from pig bile is reported. Synthetic standards and bile samples were chromatographed on a C18 reversed phase column using acetonitrile/water/tetrabutyl ammonium phosphate as an isocratic mobile phase at a flow rate of 1 mL/min. Detection of the ion-pairs was at 214 nm. The method permits efficient separation of all conjugated pig biliary bile salts without prior modification or treatment of the samples. Analysis of 12 pig biles showed that 85% of the bile salts are conjugated to glycine. The three main conjugated bile salts were glyco-3 alpha,6 alpha,7 alpha-trihydroxy-5 beta-cholanoic acid (GHC), glyco-3 alpha,7 alpha-dihydroxy-5 beta-cholanoic acid (GCDC), and glyco-3 alpha,6 alpha-dihydroxy-5 beta-cholanoic acid (GHDC). Glyco-3 alpha-hydroxy-6-oxo-5 beta-cholanoic acid (G3 alpha 6oxo), tauro-3 alpha,7 alpha-dihydroxy-5 beta-cholanoic acid (TCDC), tauro-3 alpha,6 alpha,7 alpha-trihydroxy-5 beta-cholanoic acid (THC), and tauro-3 alpha,6 alpha-dihydroxy-5 beta-cholanoic acid (THDC) were found to contribute each for 4 to 5% to the total. An excellent correlation was found between the sum of conjugated bile salts quantitated by high-performance liquid chromatography (HPLC) and values obtained by conventional enzymatic assay. Simplicity, efficiency and relative rapidity of the method render it suitable for routine analyses.

Animals↗
PubMed1988

Intestinal absorption of bile acids in the pig. Role of distal bowel.

The role of distal bowel in intestinal recycling of total bile acids was investigated in five healthy, conscious, normally fed pigs. Total bile acids appearing in the portal blood of fistulated animals were measured when bile irrigated the whole bowel (control period) and again when it was diverted at 1 m proximal to the ileocecal valve so that enterohepatic circulation was limited to only the last meter of ileum plus large bowel. Measurements were taken just after the bile had been diverted and then four days later when a new steady state was reached. Under steady-state conditions bile acid reabsorption rate in distal bowel was 20% of the normal rate. This result has been discussed taking into account the high but transient ability of distal bowel to spare bile acids measured in the first hours after bile diversion. The present experiment, together with some other in vivo trials on small laboratory animals, indicate that the proximal bowel may take a large part in bile acid absorption and that we need to reevaluate the notion that bile acid absorption takes place mainly in distal bowel.

Animals↗
PubMed1986

Enterohepatic circulation of bile acids in pigs: diurnal pattern and effect of a reentrant biliary fistula.

The present studies were undertaken 1) to assess the quantitative absorption of total bile acids in the portal vein of normally fed, unanesthetized pigs with an intact biliary tract and 2) to evaluate the effect of a chronic reentrant biliary fistula on absorption. In the intact biliary tract group (5 pigs), mean total bile acid concentration averaged 83.9 +/- 2.0 and 15.6 +/- 0.6 microM in portal and arterial blood, respectively, and 216.9 +/- 20.4 mmol of total bile acids were absorbed over 24 h. Time courses of blood concentration and absorption were described all along the light-dark cycle, and hepatic uptake averaged 79.3 +/- 0.5%. A reentrant choledocal fistula in the upper duodenum (5 pigs) did not affect mean daily blood concentrations (87.5 +/- 2.4 and 19.1 +/- 0.8 microM in portal and arterial blood, respectively), daily absorption (226.4 +/- 23.7 mmol, i.e., 93.5% of the daily secretion), or hepatic uptake (76.4 +/- 1.1%), but it did seem to influence the daily kinetics of blood concentration and absorption. These studies supply quantitative and kinetic data about the absorptive stage of the enterohepatic cycle in pigs and show that a bile fistula is suitable for the study of biliary dynamics.

Animals↗
PubMedDate not supplied

Intestinal permeability of Irish setter puppies challenged with a controlled oral dose of gluten.

A combined test of intestinal permeability using lactulose (L) and rhamnose (R), and absorptive function using xylose (X) and 3-O-methylglucose (G), was carried out at four, six, eight and 16 weeks of age in 22 healthy control and six gluten-sensitive Irish setter (IS) dogs fed a diet containing a controlled dose of gluten from weaning. Comparisons were made with two groups of 12 healthy control dogs of breeds other than IS, one fed the same diet as the setters and the other fed a gluten-free diet. Gluten-sensitive IS showed a rise in permeability (mean [SEM] urinary L/R) from 0.23 (0.07) at four weeks to 0.39 (0.05) at eight weeks, remaining at 0.36 (0.04) at 16 weeks. These results were significantly higher in gluten-sensitive than control IS at six, eight and 16 weeks, compatible with jejunal biopsy lesions characteristic of gluten-sensitive enteropathy demonstrated in affected dogs at 16 weeks. Urinary L/R ratios of control dogs of breeds other than IS peaked at six weeks 0.27 (0.02), and were significantly higher than those of control IS at six and eight weeks, demonstrating differences in permeability between Irish setter dogs and other breeds at this age. There were no significant differences in urinary X/G ratios at six, eight and 16 weeks of age between any of the groups of dogs challenged with gluten. Urinary L/R and X/G ratios were similar in the control dogs of breeds other than IS fed gluten-containing and gluten-free diets. These findings indicate that intestinal permeability testing of puppies during controlled oral gluten challenge provides a practical screening test for gluten sensitivity in Irish setter dogs at an early age.

Administration, Oral↗