PubMed Health⌕ Search

Biomedical subjects

J Odle

Publications and source records attributed to J Odle.

At least 55 records · Page 3Linked to original sources
PubMed1995

Carnitine affects octanoate oxidation to carbon dioxide and dicarboxylic acids in colostrum-deprived piglets: in vivo analysis of mechanisms involved based on CoA- and carnitine-ester profiles.

Newborn, colostrum-deprived piglets (n = 21) were used to study the effects of L-carnitine supplementation on the in vivo oxidation of [1-14C]octanoate to CO2 and dicarboxylic acids. Pigs were fitted with arterial and bladder catheters and were infused with octanoate (supplying 35-100% of piglets' energy expenditure) and with or without valproate for a period of 24 h. After achieving steady-state octanoate oxidation, carnitine was coinfused [50 mumol/kg 0.75 prime plus 20 mumol/h.kg 0.75)], and deviations in the octanoate oxidation rate, dicarboxylic acid excretion rate, and carnitine metabolism were monitored. At the end of the 24-h infusion, samples of liver and muscle were analyzed for carnitine- and CoA-esters by HPLC. Carnitine stimulated octanoate oxidation by 7% (P < 0.05) and decreased dicarboxylic acid excretion by 45% (P < 0.05). Carnitine supplementation increased (P < 0.05) concentrations of carnitine and acetyl carnitine in hepatic tissue (three- and 55-fold, respectively) and plasma (seven- and 11-fold); whereas, muscle-carnitine concentration doubled upon carnitine supplementation, but acetyl carnitine concentration remained unaltered. Urinary excretion of acetyl and free carnitine also increased with carnitine supplementation, but accounted for < 10% of carnitine infused. Hepatic total CoA and CoA esters increased with carnitine supplementation, whereas muscle acetyl-CoA decreased. Valproate had only marginal effects on octanoate metabolism. These data confirm the hypothesis that carnitine effects the in vivo oxidation of octanoate in colostrum-deprived piglets and suggest that the effects may be mediated by aiding the export of excess acetyl groups from muscle or by enhancing uptake of octanoate into liver mitochondria.

Animals↗
PubMed1995

Contribution of D-(-)-3-hydroxybutyrate to the energy expenditure of neonatal pigs.

In vivo oxidation rate of arterially infused D-(-)-3-hydroxybutyrate (3HB) was measured in 1-2-d-old-piglets. Twelve piglets (1.4 kg) were randomly assigned to a 12 h continuous infusion of 3HB at 19.5, 37.8, 55.8 or 74.5 mumol/min along with -31 kBq/h of [3-14C]3HB. Piglets were housed in respiration chambers allowing collection of total expired CO2 over 20-min intervals for the 12 h infusion and 6 h washout. Oxidation of 3HB was calculated from the quantity and specific radioactivity of expired CO2 for 20-min collection periods at 6, 9 and 12 h for each piglet and collectively plotted against plasma 3HB concentration measured in blood drawn during those 20-min periods. A Lineweaver-Burk plot of these data yielded a Km of 0.62 +/- 0.07 mmol/L and Vmax of 0.74 +/- 0.02 mmol ATP equivalents/(min.kg 0.75) (parameter estimate +/- SD), which could account for 32% of the piglet mean total ATP turnover of 2.3 mmol/(min.kg 0.75). These data show that 3HB oxidation is a linear function of plasma concentration in the physiologic range measured in piglets (0.006 mmol/L to 0.1 mmol/L) and within this range would account for 0.3% to 4.5% of piglet energy requirement. Oxidation of 3HB can meet a maximum of 30 to 40% of piglet energy requirement at unphysiologically high 3HB concentrations (> 3 mmol/L).

3-Hydroxybutyric Acid↗
PubMed1995

Effects of glycine and bovine serum albumin on inhibition of propionate metabolism in ovine hepatocytes caused by reduced phenolic monomers.

Hepatocytes isolated from sheep were incubated in the presence of reduced phenolics and glycine to determine the effects of these compounds on hepatic propionate metabolism in vitro. 3-Phenyl-propionic (PPA) or t-cinnamic (CA) acids, but not benzoic (BA) or 3-(4-hydroxyphenyl)propionic (4OHPPA) acids, decreased conversion of propionate to glucose at .05 mM in the absence of supplemental glycine. At 1.2 mM, all reduced phenolics decreased conversion of propionate to glucose in the absence of supplemental glycine. Addition of glycine to the incubation medium linearly alleviated the inhibition by BA, PPA, or CA, suggesting that physiological glycine concentrations limited alleviation of inhibition of propionate metabolism. Hippuric acid production increased as glycine concentration increased in the presence of PPA, CA, or 4OHPPA. Bovine serum albumin did not alleviate inhibition of conversion of propionate to glucose caused by BA, PPA, or CA and slightly alleviated inhibition caused by 4OHPPA (.4 mM). Of the reduced phenolics tested, PPA is the most likely to inhibit gluconeogenesis from propionate in ovine liver in vivo.

Animals↗
PubMed1995

Prenatal androgenization of lambs: II. Metabolism in adipose tissue and liver.

In vitro measurements of metabolism were made in subcutaneous and perirenal adipose tissue (AT) and liver from prenatally androgenized ewe lambs (TE), control ewe lambs (CE), and control wether lambs (CW). In adipose tissue slices, release of glycerol or fatty acids into the medium was not different among treatments, but glycerol release was greater (P < .01) from subcutaneous AT than from perirenal AT. Basal fatty acid release and the free fatty acid pool were greater (P < .05) for perirenal AT than for subcutaneous AT; fatty acid release and the fatty acid response (increased NEFA in media and tissue) were increased more by lipolytic stimuli in subcutaneous AT than in perirenal AT. Adipose tissue from CW had the greatest (P < .05) fatty acid response under conditions of near-maximal stimulation; rates from TE were intermediate to those from CW and CE. Incorporation of glucose into fatty acids and glycerol in subcutaneous AT was lowest (P < .05) for TE. Oxidation of glucose and acetate to CO2 and incorporation of acetate into fatty acids or glycerol in subcutaneous AT, glucose and acetate metabolism in perirenal AT, and cellularity measurements for both AT did not differ among treatments. In liver slices, oxidation of [1-14C]propionate to CO2 was greater (P < .05) for CE than for TE or CW, and gluconeogenic capacity from [1-14C]propionate tended to be greater (P < .10) for CE than for TE. Glucose and CO2 production from [2-14C]propionate, [U-14C]alanine, or [U-14C]glycerol and total and peroxisomal first cycle of beta-oxidation of [1-14C]palmitate were not altered by prenatal androgenization or sex. There were no effects (P > .1) of prenatal exposure to testosterone on mitochondrial protein content of liver, rates of mitochondrial state 3 or state 4 respiration, the ratio of ADP:oxygen in the presence of respiratory substrates, or hepatic contents of lipid, triglyceride, or glycogen. Protein content of liver was greater (P < .05) for CW than for CE; TE were intermediate. Collectively, there were minimal modifications of in vitro metabolism in AT or liver attributable to prenatal androgenization or sex that would directly influence ADG and carcass composition.

Acetates↗
PubMed1995

Effects of induced or delayed parturition and supplemental dietary fat on colostrum and milk composition in sows.

Two experiments were conducted to evaluate the effects of inducing premature parturition on the composition of colostrum and milk and the effects of dietary fat supplementation on colostrum and milk composition from premature and delayed farrowing sows. In Trial 1, eight sows were allowed to farrow naturally (d 114, NF sows) and eight sows were induced to farrow (IF sows) prematurely by injection of prostaglandin F2 alpha on d 112 of gestation. Average fat content of sow's milk during the first 12 h postpartum was lower for IF than for NF sows (P < .05), as was overall mean fat percentage (P < .05). In Trial 2, 53 sows were randomly assigned in a 2 (diets) x 5 (parturition treatments) factorial experiment. Dietary treatments fed during the last 2 wk of gestation and throughout lactation were control diet and added fat diet (control diet plus 10% corn oil). Parturition treatments included 1) natural farrowing (d 114), induction of parturition with prostaglandin F2 alpha on 2) d 110, 3) d 111, or 4) d 112 of gestation, and 5) delay of parturition with progesterone followed by injection of prostaglandin on d 115. The added fat diet increased milk fat percentage compared with the control diet (P < .01). Colostral fat percentage was reduced by induction of premature farrowing (d 110 or 111) in sows fed the control diet but was unaffected in sows fed added dietary fat (interaction, P < .05). Mean fat content of colostrum was not reduced in groups receiving the added fat diet that were induced to farrow prematurely.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Emulsification and fatty acid chain length affect the kinetics of [14C]-medium-chain triacylglycerol utilization by neonatal piglets.

In vivo oxidation kinetics of medium-chain triglycerides (MCT) composed of [1-14C]hexanoate (tri-6:0) or [1-14C]octanoate (tri-8:0) were compared after being fed to day-old piglets (1.4 kg; n = 4/treatment). Animals were fitted with arterial and oro-gastric catheters and placed into respiration chambers held at 35 degrees C. The radiolabeled MCT were fed in equimolar amounts (6.5 mmol/kg0.75), in either nonemulsified form or as 30% (v/v) emulsions, using polyoxyethylene sorbitan monooleate as an emulsifier. Expired CO2 was quantified and specific radioactivity (Bq/mumol) determined at 20-min intervals over 24 h, and serial blood samples were drawn for measurement of plasma hexanoate and octanoate by HPLC. The rate [mumol/(h.kg0.75)] and extent (mmol/kg0.75) of MCT oxidative utilization (i.e., composite of digestion, absorption and oxidation) were calculated from the kinetics of 14CO2 expiration. Emulsification increased both the rate and extent of MCT oxidative utilization by > 20% regardless of fatty acid chain length (P < 0.05). Maximal MCT oxidation rates occurred at 3.5 h after feeding and were sufficient to meet up to 48% of the piglets' energy expenditure. The maximal rate of tri-6:0 oxidative utilization exceeded that of tri-8:0 by 37% (P < 0.05), but the extent of utilization was not affected by fatty acid chain length. Plasma medium-chain fatty acid concentrations were in agreement with these observations, being higher in pigs fed emulsified MCT than in pigs fed nonemulsified MCT (P < 0.05) and being higher in pigs fed tri-6:0 than in animals fed tri-8:0 (P < 0.05). Collectively, these data demonstrate that newborn piglets can effectively digest, absorb and oxidize MCT, that utilization is improved with emulsification, and that tri-6:0 is utilized more rapidly than tri-8:0.

Analysis of Variance↗
PubMed1994

Effect of orally administered epidermal growth factor on intestinal recovery of neonatal pigs infected with rotavirus.

The effect of oral epidermal growth factor (EGF) on histological and biochemical changes in epithelium in the small intestine was studied in colostrum-deprived neonatal pigs. Forty-eight pigs were infected at 4 days of age with 2 x 10(7) plaque-forming units of porcine group A rotavirus and orally fed a simulated sow-milk diet supplemented with 0.0, 0.5, or 1.0 mg/L recombinant human EGF. Sixteen noninfected pigs were fed a diet without EGF supplementation. Infected pigs developed severe diarrhea; they also consumed 25% less food and gained 60% less weight than noninfected pigs. Pigs were killed 8 days postinfection to collect samples at seven equidistant points in the small intestine. Rotavirus infection decreased villus height by 37% and reduced specific activity of lactase by 54%, of leucine aminopeptidase by 43%, and of alkaline phosphatase by 54% in the small intestine, compared with noninfected pigs. Only the supraphysiological dose of EGF (1.0 mg/L) consistently increased villus height in the proximal and mid-small intestine and lactase-specific activity in the mid-small intestine of rotavirus-infected pigs. However, this dose was only partially effective in restoring intestinal mucosal dimensions and enzyme activities. Supplemental EGF did not hasten the resolution of diarrhea. These data indicate that high physiological levels of EGF are beneficial in stimulating recovery of epithelium in the small intestine following rotavirus infection.

Administration, Oral↗
PubMed1994

Insulin-like growth factors and insulin-like growth factor binding proteins in porcine serum and milk throughout lactation.

IGF-I, IGF-II, and IGF binding proteins (IGFBP) were characterized in porcine serum, colostrum, and milk on d 1-28 postpartum. IGF-I and -II were measured by heterologous RIA. Serum IGFBP were characterized by Western ligand blotting and milk IGF binding activity by [125I]-IGF binding assay. IGF-II accounted for 70-85% of serum IGF and rose 2-fold between d 1 and d 28. Serum IGF-I was unaffected by duration of lactation. Milk IGF-II concentrations were higher than IGF-I concentrations on d 1-7 postpartum. After d 10, milk IGF-I and IGF-II contents were not significantly different. Serum contained IGFBP with M(r) of 43, 39, 34, 28, and 24 kD. Over the course of lactation, the 43- and 39-kD bands increased, the 24-kD band decreased, and the 34- and 28-kD bands were unchanged. Milk IGF binding activity increased between d 1 (28%) and d 3 (44%), then declined until d 28 (7%). Serum and milk were separated by isoelectric focusing into 20 fractions, across a gradient from pH 3 to 10, that were screened for IGFBP by Western ligand blotting. Milk contained six IGFBP of similar M(r) as serum IGFBP; however, the relative amounts of the IGFBP and their apparent isoelectric points differed. In conclusion, porcine milk contains both IGF-I and -II, with IGF-II predominating. Several IGFBP with similar M(r) as those found in serum are present in milk. IGF peptide concentrations were highest in prepartum secretions and colostrum, whereas IGF binding activity peaked on d 4 of lactation.

Animals↗
PubMed1994

Use of the piglet to study the role of growth factors in neonatal intestinal development.

Milk growth factors are thought to contribute to postnatal gastrointestinal growth. The roles of epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) in the neonatal piglet intestine were investigated. In the first study, piglets were infected with rotavirus on d 4 postpartum and received formula containing 0, 500 or 1000 micrograms/l of EGF for 8 days. A non-infected control group received no EGF. Infected piglets developed severe diarrhea and gained 60% less weight than controls. Rotaviral infection caused a 37% decrease in villus height and 40% decreases in intestinal enzyme activities compared to control. Oral EGF increased villus height and lactase activity in a linear dose-response fashion. Our results suggest that supplementation of formulas with high physiological levels of EGF may aid in small intestinal recovery. A second study investigated absorption of orally administered IGF-I. Newborn piglets were fitted with catheters via the umbilical artery and vein. Piglets were given formula containing 25 microCi of [125I]-IGF-I and blood samples were drawn for 24O min. Total radioactivity, protein bound counts, and counts immunoprecipitable with an antibody to IGF-I were determined in plasma. Radioactivity was detected in portal and arterial plasma within 15 min and rose throughout the study, however, protein bound counts were stable at 20-30% of total counts between 30 and 180 min postgavage. Approximately 10% of the counts were immunoprecipitable by a polyclonal antibody to IGF-I, suggesting that up to 10% of orally administered IGF-I may be absorbed intact.

Animals↗
PubMed1993

Medium-chain fatty acid oxidation in colostrum-deprived newborn piglets: stimulative effect of L-carnitine supplementation.

To investigate the role of L-carnitine in medium-chain fatty acid (MCFA, fatty acids with 6-12 carbons) metabolism, 16 newborn pigs were fitted with umbilical arterial catheters. Pigs were placed in respiration chambers, and [1-14C]MCFA were infused for 9-12 h providing energy equivalent to 50-175% of the animals' metabolic rate. After 5-7 h (carnitine-free infusion period) of MCFA infusion, a primed (12.5, 25 or 50 mumol) co-infusion of L-carnitine [5, 10 or 20 mumol/(h.kg0.75), respectively] was started and maintained for 4-5 h (carnitine infusion period). The fatty acid oxidation rate (MCFA-derived CO2/total CO2 x 100) was calculated based on the specific radioactivity of expired CO2 (measured per 20-min interval) and the specific radioactivity of the MCFA infused. A single-pool exponential curve was fitted to the fatty acid oxidation rate of the carnitine-free infusion period and was extrapolated to the carnitine infusion period. For each piglet, the average difference between fatty acid oxidation rate during the carnitine infusion period and the extrapolated curve was calculated and tested for significance using a t test. Under steady state conditions, MCFA oxidation accounted for 40% of MCFA infused. Carnitine, independent of the level, increased the fatty acid oxidation rate by as much as 20% if the energy provided as MCFA exceeded 50% of the metabolic needs of the pig (P < 0.01), and the response above 50% was proportional to the relative rate of fatty acid infusion (increase in fatty acid oxidation rate = -3.9 + 0.07 x infusion rate, r0.76).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Plasma beta-hydroxybutyrate after octanoate challenge: attenuated ketogenic capacity in neonatal swine.

Suckling neonatal pigs (NP, 24 h old) do not exhibit elevated blood ketone bodies (KB). Mature swine have relatively high KB under certain conditions, suggesting an ontogeny of ketogenesis. Thus we evaluated the hypothesis that NP possess a relatively attenuated ketogenic capacity vs. weaned pigs (WP) and mature pigs (MP). Fasted animals were given an intraperitoneal dose of octanoate (C8), and plasma beta-hydroxybutyrate (beta-OHB) and C8 were monitored over 180 min. Newborn (NR, 24 h old) and mature rabbits (MR, > 1 yr old) were also compared. Linear regressions of plasma beta-OHB (microM) vs. plasma C8 (microM) were calculated for C8 < 1,000 microM. There was a significant linear relationship of beta-OHB regressed against C8 in all ages of pigs (P < 0.001) and in NR (P = 0.024). The slope for NP (0.08) was one to two orders of magnitude below slopes for older pigs (WP = 1.19 and MP = 0.78, P < 0.01 vs. NP), NR *6.97, P < 0.05), and MR (4.04, NS). The beta-OHB peak in NP (40.9 +/- 4.4 microM) was 1-8% of the maxima in other animals (P < 0.05) despite a C8 maximum (2.3 +/- 0.3 mM) similar to that of WP (1.9 +/- 0.7 mM) and MR (2.9 +/- 1.2 mM) (P > 0.05, NS). The data are consistent with the hypothesis that NP have a poor capacity for ketogenesis.

3-Hydroxybutyric Acid↗
PubMed1993

Utilization of medium-chain triglycerides by neonatal pigs: effects of emulsification and dose delivered.

Four trials were conducted using 86, 24-h-old pigs to evaluate the utilization of medium-chain triglycerides (MCT). Effects of emulsification and amount of MCT fed were examined. After a 4-h period during which feed was withheld, pigs were force-fed MCT (containing 75% octanoate and 25% decanoate), marking time 0 of the experiment. Blood samples were obtained at 1 and 2 h for subsequent medium-chain fatty acid (MCFA) analysis. In Trials 1 (six pigs/treatment) and 2 (four pigs/treatment) the response to three emulsifying agents was compared to a nonemulsified (NE) control. Twenty milliliters of a 30% (vol/vol) emulsion of MCT or 6 mL of NE MCT was administered. Concentrations of MCFA at 1 h in pigs receiving a Tween 80 (polyoxy-ethylene [20] sorbitan monooleate) emulsion were 3- to 19-fold higher than concentrations in animals administered a gum arabic/gum tragacanth emulsion, a lecithin emulsion, or NE MCT. Trials 3 (eight pigs/treatment) and 4 (six pigs/treatment) were conducted to determine the plasma MCFA concentrations resulting from feeding increasing levels of NE (3, 6, 9, or 12 mL of MCT) or emulsified MCT oil (2, 4, 6, or 8 mL in a 30% Tween 80 emulsion). Plasma octanoate concentrations measured at 1 h increased linearly (P < .05) with increasing MCT dosage through 9 mL of NE and 6 mL of emulsified MCT. A transient narcosis was observed in 8 of 12 animals that received 6 or 8 mL of emulsified MCT and was most pronounced 1 to 2 h after feeding, which roughly corresponded to peak plasma MCFA concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Emulsification and fatty-acid chain length affect the utilization of medium-chain triglycerides by neonatal pigs.

Three experiments were conducted using 52 pigs between 22 and 35 h of birth to determine the effects of emulsification and fatty-acid chain length on utilization of medium-chain triglycerides (MCT). After a 4-h period during which feed was withheld, pigs were force-fed 6 mL of nonemulsified (NE) MCT or 20 mL of a 30% (vol/vol) Tween 80-(polyoxy-ethylene [20] sorbitan monooleate) MCT emulsion, marking time 0, and serial blood samples were drawn throughout 8 h for analysis of medium-chain fatty acid (MCFA) concentrations by HPLC. In Exp. 1, pigs received either NE or emulsified Tri-C4, -C5, -C6, or -C7. The emulsified treatments were discontinued due to deaths caused by coma resulting from high concentrations (up to 12 mM) of plasma MCFA. Concentrations in pigs fed emulsified MCT were 2.5-fold higher than those in pigs fed NE MCT. In pigs fed NE MCT, concentrations of even-chain-length MCFA were higher than those of odd-chain-length MCFA (P < .001), with a tendency for C6 to be higher than C4 (P < .1). In Exp. 2 and 3, pigs received an equimolar mixture of MCT in either emulsified or NE form. In Exp. 2, the mixture contained Tri-C4 through Tri-C7; whereas, in Exp. 3 the mixture contained Tri-C4, -C6, -C8, and -C10. A three-way interaction (emulsion x fatty acid x sample time; P < .05) was observed in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Quantification of carnitine esters by high-performance liquid chromatography. Effect of feeding medium-chain triglycerides on the plasma carnitine ester profile.

A high-performance liquid chromatographic (HPLC) technique was developed using commercially available derivatization reagents and commonly used reversed-phase HPLC column chemistry to analyze plasma samples for their carnitine ester content. The method proved to be sufficiently sensitive to determine changes in the carnitine ester profile in plasma resulting from metabolic disorders or metabolic insults. The method was tested using plasma samples obtained from pigs fed medium-chain triglycerides (MCT) of different chain lengths (four to seven carbons). The MCT feeding was associated with transient increases in plasma carnitine and carnitine esters, and feeding odd-chain MCT (tri-C5 or tri-C7) led to elevated levels of propionylcarnitine in plasma.

Animals↗
PubMed1992

Urinary excretion of taurine as a function of taurine intake: potential for estimating taurine bioavailability in the adult cat.

Urinary taurine excretion increases markedly when excess taurine is consumed. Experiments were designed to characterize this response in an attempt to develop an assay system for taurine bioavailability in common cat foods using an adult cat model. Initial studies investigated the time course of changes in urinary taurine excretion in response to alterations in taurine intake. The rate of urinary taurine excretion decreased rapidly when cats were switched from a casein diet supplemented with 0.2% crystalline taurine to a diet containing no supplemental taurine, reaching steady-state in 2 d. In contrast, urinary taurine excretion by cats switched from low to high taurine did not plateau until 6 to 7 d. Subsequently, cats (n = 18) were fed a casein diet containing graded levels of crystalline taurine (0, 0.025, 0.05, 0.10, 0.15 or 0.20%). After a 7-d adjustment period, urinary taurine excretion was quantified over a 5-d collection period and also by cystocentesis, and blood taurine levels were measured on d 6. Plasma taurine increased linearly (r = 0.88) as taurine intake increased, while whole-blood taurine increased asymptotically, reaching 95% of maximum concentration at a taurine intake of 93 mu mole/(kg body weight.d). The rate of urinary taurine excretion increased only slightly as taurine intakes increased to 96 mu mol/(kg body weight.d), but increased markedly (15-fold) thereafter. The same pattern was observed whether urinary taurine excretion was expressed as mu mole/(kg body weight.d) from total urine collection or as mu mole/g creatinine from cystocentesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1992

Comparison of measured carbon dioxide production with that obtained by the isotope dilution technique in neonatal pigs: observations on site of infusion.

Fifteen newborn pigs (1.5 kg) were used to estimate CO2 "production" over a 5-h experiment. In each piglet, the average expired air CO2 irreversible loss rate measured over 15-min intervals was compared with an estimate of CO2 "produced" by a continuous infusion of NaH14CO3 into either the aortic artery (seven pigs) or the portal vein (eight pigs). The specific radioactivity (Bq/mumol) of the expired CO2 taken over consecutive 15-min intervals during the 5-h period was fitted to an exponential model to predict the specific radioactivity at steady state. This specific radioactivity was used to calculate the total CO2 irreversible loss rate and to correct for the difference in tracer infused in relation to tracer excreted at 5 h (76 to 78%). The estimated CO2 "produced" tended to be higher (P < 0.12) when the aortal rather than the portal infusion site was used [571 vs. 498 mumol/(min.kg0.75)]. The isotope dilution technique significantly (P < 0.05) overestimated the expired air CO2 regardless of whether the aortal [571 vs. 469 mumol/(min.kg0.75)] or portal [498 vs. 447 mumol/(min.kg0.75)] routes of infusion were used.

Animals↗