Oxygen Consumption by Portal-Drained Viscera of Cattle: Comparison of Analytical Methods and Relationship to Whole Body Oxygen Consumption

Huntington, G. B.; Tyrrell, H.F.

doi:10.3168/jds.s0022-0302(85)81157-7

Cited by 37 publications

(21 citation statements)

References 8 publications

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“…Glutamate and glutamine analyses began immediately after all samples were collected and processed. Blood 0, content was determined using an oximeter (Lexington Instruments, Watham, MA) as described by Huntington & Tyrrell (1985).…”

Section: Blood Sampling and Blood Flow Measurementsmentioning

confidence: 99%

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Partition of portal-drained visceral net flux in beef steers

Reynolds

Huntington

1988

Br J Nutr

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1. Blood from chronic indwelling catheters in the caudal aorta and anterior mesenteric, gastrosplenic and hepatic portal veins was used to measure blood flow and net flux of oxygen, glucose and nitrogenous compounds across hepatic portal-drained viscera (PDV), post-stomach (anterior mesenteric-drained viscera (MDV)) and stomach tissues of two beef steers (390 kg mean live weight).2. Steers were fed in sequence on (I) chopped lucerne (Medicago sariva) hay (twelve meals/d), (2) chopped lucerne hay (two meals/d) and (3) a pelleted concentrate diet containing 780 g ground maize/kg (two meals/d). The lucerne hay and concentrate contained 26.5 and 16.8 g nitrogen/kg respectively.3. Five measurements of net flux (blood flow multiplied by venous-arterial concentration differences (VA)) were obtained hourly on 2 d for each dietary regimen, beginning 0.5 h before feeding at 08.00 hours. Blood flow wdS measured by downstream dilution of p-aminohippurate (PAH).4. Blood flow across MDV averaged 42% of PDV blood flow (665 litres/h). 5. Net use of 0, across MDV accounted for 51 % of net PDV use of 0, (920 mmol/h). This disproportionate use of 0, in relation to blood flow was due to greater VA for 0, across MDV than across stomach tissues. Dietary regimen had no effect on the proportions of PDV blood flow and net 0, consumption attributable to MDV or stomach tissues.6. When lucerne was given, net glucose use across MDV represented 69% of PDV use (35 mmol/h). When concentrate was given, MDV glucose use switched to net absorption (29 mmol/h), reducing net PDV glucose use to 1 mmol/h. 7. When concentrate was given, net MDV absorption of a-amino-N (AAN) increased from 98 to 190 mmol/ h, yet net PDV absorption (101 mmol/h) was not affected. Net stomach AAN flux increased from -7 to -69 mmol/h when concentrate was given, negating the increase in net MDV absorption.8. Net absorption of ammonia-N across MDV represented 28 and 52% of net PDV absorption when lucerne and concentrate were given respectively. Net NH,-N absorption across PDV was lower when lucerne was given than when concentrate was given (295 v. 154 mmol/h), reflecting lower dietary N intake (153 v. 83 g/d). Net MDV absorption of NH,-N was not affected by diet. Net removal of blood urea-N (BUN) across PDV (101 mmol/h) was not affected by diet. Across MDV, BUN removal was lower when concentrate was given than when lucerne was given (32 v. 77 mmol/h). In beef steers, MDV tissues account for substantial portions of net flux of nonprotein-N across PDV and are responsible for essentially all PDV absorption of AAN.

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Section: Blood Sampling and Blood Flow Measurementsmentioning

confidence: 99%

“…Uptake of 0, is a measure of metabolic activity and can be used to estimate heat production attributable to respiratory metabolism (Huntington & Tyrrell, 1985). Tissues of MDV accounted for 51% of PDV uptake of 0, and 41 % of PDV blood flow.…”

Section: Blood Flowmentioning

confidence: 99%

Partition of portal-drained visceral net flux in beef steers

Reynolds

Huntington

1988

Br J Nutr

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“…Whole-blood O 2 concentration was calculated using the following equation: O 2 (mM) 5 Hgb 3 1.34 3 % O 2 3 (1/22.4), Splanchnic energy metabolism in forage-fed sheep where Hgb is blood hemoglobin (g/l), 1.34 is ml of O 2 /g of hemoglobin, % O 2 is the O 2 saturation percentage and 22.4 is O 2 volume at standard temperature and pressure (ml of O 2 /mmol of O 2 ) (Huntington and Tyrrell, 1985). The O 2 consumption by the PDV and TSP was calculated as the product of blood flow through PDV and TSP times portal-arterial and hepatic-arterial differences in O 2 concentration, respectively.…”

Section: Animals and Treatmentsmentioning

confidence: 99%

“…The O 2 extraction ratio was calculated as (A O2 -V O2 )/A O2 , where A O2 and V O2 are arterial and venous O 2 concentrations, respectively (Jones et al, 1989). Heat production was calculated assuming 4.89 kcal/l of O 2 consumed (Huntington and Tyrrell, 1985). Net splanchnic energy flux regarding the estimated MP intake was calculated using heats of combustion (MJ/mol) of metabolites shown in Table 1.…”

Section: Animals and Treatmentsmentioning

confidence: 99%

Energy metabolism by splanchnic tissues of mature sheep fed varying levels of lucerne hay cubes

Elsabagh

Goto

Sugino

et al. 2013

Animal

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The objective of this study was to determine the pattern of energy metabolites net flux across the portal-drained viscera (PDV) and total splanchnic tissues (TSP) in mature sheep fed varying levels of lucerne hay cubes. Four Suffolk mature sheep (61.4 6 3.6 kg BW) surgically fitted with multi-catheters were fed four levels of dry matter intake (DMI) of lucerne hay cubes ranging from 0.4-to 1.6-fold the metabolizable energy (ME) requirements for maintenance. Six sets of blood samples were simultaneously collected from arterial and venous catheters at 30-min intervals. With increasing DMI, apparent total tract digestibility increased linearly and quadratically for dry matter (P , 0.05), quadratically (P , 0.05) with a linear tendency (P , 0.1) for organic matter and tended to increase quadratically (P , 0.1) for NDF. PDV release of volatile fatty acids (VFA) and b-hydroxybutyric acid was relatively low at 0.4 M and then linearly increased (P , 0.05) with increasing DMI. Net PDV flux of non-esterified fatty acids showed curvilinear decrease from 0.4 to 1.2 M and then increased at 1.6 M. The respective proportions of each VFA appearing in the portal blood differed (P , 0.05) with DMI and this difference was more obvious from 0.4 to 0.8 M than from 0.8 to 1.6 M. Heat production, as a percentage of ME intake (MEI), decreased linearly (P , 0.05) with increasing DMI accounting for 37%, 21%, 16% and 13% for PDV and 62%, 49%, 33% and 27% for TSP at 0.4, 0.8, 1.2 and 1.6 M, respectively. As a proportion of MEI, total energy recovery including heat production, decreased linearly with increasing DMI (P , 0.05) accounting for 113%, 83%, 62% and 57% for PDV and 140%, 129%, 86% and 83% for TSP at 0.4, 0.8, 1.2 and 1.6 M, respectively. Regression analysis revealed a linear response between MEI (MJ/day per kg BW) and total energy release (MJ/day per kg BW) across the PDV and TSP, respectively. However, respective contributions of energy metabolites to net energy release across the PDV and TSP were highly variable among treatments and did not follow the same pattern of changes in DMI.

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“…Negative values denote net tissue uptake or removal, and positive values indicate net release of a metabolite. The O 2 concentration in blood was calculated as resulted from the sum of the O 2 associated to haemoglobin plus the O 2 dissolved in the blood aqueous phase (Huntington & Tyrrell, ). The molar concentration of O 2 was calculated considering the gas constant of 22.4 ml per mmol.…”

Section: Methodsmentioning

confidence: 99%

Oxygen uptake and net flux of metabolites by splanchnic tissues of sheep in response to short‐term mesenteric infusion of nitrogenous compounds

Stefanello

Mezzomo

Zeni

et al. 2018

Animal Physiology Nutrition

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This study was conducted in an attempt to quantify the impact of N load on splanchnic tissues metabolism of sheep. The trial was conducted with four male sheep (45 ± 2.5 kg body weight (BW)) surgically implanted with chronic indwelling catheters into the portal, hepatic and mesenteric veins. Blood flow and metabolic flux through portal-drained viscera (PDV), liver and total splanchnic tissues (ST) were measured daily following a 4 × 4 Latin Square experimental design, where sheep were continually infused into the mesenteric vein with a physiological saline (0.15 m NaCl) solution during 90 min followed by the infusion, during more 120 min, of either solution: physiological saline (control), 0.250 mNH HCO , 0.250 m L-alanine or 0.125 m L-arginine, all of them infused at a rate of 1.5 ml/min to provide 375 μmol N/min. During the treatment infusion period, the net removal of ammonia N and the net production of urea N by liver were higher (p < .05) in NH HCO infused sheep Based on oxygen consumption, and on average of all treatments, the heat produced by liver and ST was on average 6 and 14 kcal/kg BW representing 16% and 38% of the metabolizable energy intake respectively. Linear relationships between variables indicated that gluconeogenesis and ureagenesis occurred concomitantly and both processes accounted for approximately 50% of total liver energy expenditure, two-thirds of it associated with gluconeogenesis. The results of the current study did not present clear evidence of the expected energy costs associated with ammonia N, alanine or arginine metabolism by liver. However, they indicated that gluconeogenesis is on average a more energy expensive process than ureagenesis.

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Oxygen Consumption by Portal-Drained Viscera of Cattle: Comparison of Analytical Methods and Relationship to Whole Body Oxygen Consumption

Cited by 37 publications

References 8 publications

Partition of portal-drained visceral net flux in beef steers

Partition of portal-drained visceral net flux in beef steers

Energy metabolism by splanchnic tissues of mature sheep fed varying levels of lucerne hay cubes

Oxygen uptake and net flux of metabolites by splanchnic tissues of sheep in response to short‐term mesenteric infusion of nitrogenous compounds

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