Splanchnic Glucose Release Research Articles

Differences in splanchnic metabolism between late gestation and early lactation dairy cows

In the transition from the pre- to postcalving state, the demands on the cow increase from support of gestation to high rates of milk production. This extra demand is met partly by increased intake but may also involve altered metabolism of major nutrients. Six multiparous Holstein cows were used to monitor changes in net fluxes of nutrients across the portal-drained viscera and liver (splanchnic tissues) between late gestation and early lactation. Blood samples were obtained simultaneously from the portal, hepatic, and subcutaneous abdominal veins and the caudal aorta 18 d before expected calving and 21 or 42 d after calving. On the day of blood sampling and the 3 d preceding sampling, cows were fed every 2h. The precalving (1.63 Mcal of net energy for lactation/kg and 1,326g of metabolizable protein/d) and postcalving (1.72 Mcal of net energy for lactation/kg and 2,136g of metabolizable protein/d) diets were based on corn silage, alfalfa hay, and corn grain. Dry matter intake increased postcalving. Net splanchnic release of glucose increased postpartum because of tendencies for both increased portal absorption and net liver release. Increased removal of lactate, rather than AA, contributed to the additional hepatic gluconeogenesis. Although portal absorption of AA increased with intake at the onset of lactation, hepatic removal of total AA-N tended to decline. This clearly indicates that liver removal of AA is not linked to portal absorption. Furthermore, net liver removal relative to total liver inflow even decreased for Gly, His, Met, Phe, and Tyr. Together, these data indicate that in early lactation, metabolic priority is given to direct AA toward milk protein production rather than gluconeogenesis, in cows fed a corn-based ration.

Quantitative aspects of ruminant predicting animal performance

AbstractRations for dairy cattle are currently balanced to meet needs for energy, protein, vitamins, and minerals. While individual vitamins and minerals are considered, energy and protein are generally treated in aggregate even though entities within those aggregates can affect milk yield and composition. Significant efforts have been undertaken to describe ruminal metabolism in detail, but descriptions of post-absorptive metabolism assume constant fractional conversions of energy and protein to milk. A quantitative understanding of nutrient metabolism by the post-absorptive tissues is required, and the splanchnic tissues are critical components of the post-absorptive system as they mediate absorption of nutrients and play a rôle in regulation of metabolite availability.Glucogenic precursor supply can significantly affect endocrine status as well as splanchnic release of glucose, acetate, lactate, ketones, and the non-essential amino acids. Although the relative affinities of the splanchnic tissues for the essential amino acids (AA) are low as compared with the udder, net clearance on a daily basis represents approximately 2/3 of the net supply to the animal due largely to recycling of AA back to the tissue bed. This could be significantly reduced by stimulating removal and use by the udder as splanchnic affinities are much lower than mammary affinities. Additionally, the essential AA composition of absorbed protein is significantly modified by these tissues due to differing affinities for each of the AA. The extent of that modification is not a fixed constant but rather a function of several factors including milk yield. The accuracy of our current feeding systems could be improved if such variable rates of substrate removal replaced current static estimates.

Intraruminal propionate supplementation modifies hindlimb energy metabolism without changing the splanchnic release of glucose in growing lambs

The influence of propionate supplementation on the splanchnic metabolism of energy-yielding nutrients and the supply of glucose to the hindlimb was investigated in growing lambs. Six rumen-cannulated and multicatheterized lambs (32.2 kg), fed frozen rye grass at 690 kJ metabolizable energy intake/d per kg body weight0.75, were infused intraruminally with a salt solution (control) or with propionate solutions at 0.55 mol/d (P1) or 0.98 mol/d (P2) according to a replicated Latin square design. In the rumen fluid, supplementation decreased the acetate:propionate molar ratio from 2.36:1 to 1.37:1, without modifying the ruminal concentrations of acetate and NH4. As a result, the portal appearance of propionate increased by 51 and 72 % with P1 and P2, respectively, and that of l-lactate doubled. Across the liver, net extraction of propionate increased by 47 and 67 % with P1 and P2, respectively. However, the net hepatic production of glucose remained unchanged, probably as the result of a substantial rise in insulin secretion and its hepatic extraction. Overall, the net splanchnic release of acetate, glucose and butyrate was not modified while that of l-lactate increased. Despite this, the net uptake of acetate, glucose, l-lactate and non-esterified fatty acids by the hindlimb increased. Propionate probably enhanced the storage of energy-yielding nutrients in the hindlimb, despite their unchanged release by the splanchnic tissues and the unmodified insulinaemia. Regulatory mechanisms are not clear.

Inter-relationships between renal metabolism (both in physiology and renal dysfunction) and the liver.

Recently, evaluation of organ-specific glucose release showed that renal glucose release is of the same order of magnitude as splanchnic glucose release during the postabsorptive period. Moreover, renal glucose release appeared to be more sensitive to hormone action than did hepatic glucose release, and appeared to have a pre-eminent role during the adaptation to various physiological and pathological conditions. The kidney is now recognized as playing a key role in interorgan glucose metabolism, and particularly in the Cori cycle and glutamine-glucose cycle. During chronic renal failure the suppression of renal glucose release, together with impaired hormone action, decreased glycogen storage and abnormal liver gluconeogenesis, are responsible for an increased risk for hypoglycaemia.

The effect of feed intake level on splanchnic metabolism in growing beef steers.

The effect of feed intake level (.6, 1.0, and 1.6 x maintenance energy and protein requirements, M) on splanchnic (portal-drained viscera [PDV] plus liver) metabolism was evaluated in six multicatheterized beef steers (398 +/- 27 kg), using a double 3 x 3 Latin square design. On the last day of each 21-d experimental period, six hourly blood samples were collected from arterial, portal, and hepatic vessels. Due to catheter patency, PDV fluxes were measured on five steers, and liver and splanchnic fluxes on four steers. Increasing intake elevated (P < .01) splanchnic release of total (T) amino acids (AA), through increases (P < .01) in PDV release of both essential (E) and nonessential (NE) AA, in spite of a tendency (P < .20) for increased liver removal of NEAA. The PDV release of AA N represented 27 and 51% of digested N for 1.0 and 1.6 x M, respectively. At 1.0 and 1.6 x M, the liver removed 34% of total AA released by the PDV. For individual AA, portal flux of most EAA increased (P < .05) with feed intake, and the increase (P < .10) in splanchnic flux was accompanied by increased arterial concentration for all EAA except histidine, lysine, and methionine. This suggests that these might be limiting AA for this diet. On a net basis, most individual NEAA were released by the PDV except glutamate and glutamine, which were removed by the digestive tract. There was a net removal of NEAA by the liver, except for aspartate and especially glutamate, which were released. Ammonia release by the PDV tended (P < .20) to increase with intake and represented 69, 53, and 45% of digested N at .6, 1.0, and 1.6 x M, respectively. Urea removed by the PDV, unaffected by intake, represented 32, 33, and 21% of the digested N. Arterial glucose concentration increased linearly (P < .01) with greater intake, whereas net liver and splanchnic glucose release increased in a quadratic (P < .05) manner. Net PDV glucose release represented 26% of net glucose hepatic release at 1.6 x M. Intake elevated (P < .10) both insulin and glucagon arterial concentrations, resulting from a larger increment of portal release (P < .01) than hepatic removal (P < .05). Intake-based variations in IGF-I and NEFA arterial concentrations (P < .05) were not related to changes in splanchnic metabolism. These results clearly show the crucial role of the splanchnic tissues in regulating the profile and quantity of AA and concentrations of glucose and pancreatic hormones reaching peripheral tissues.

Effects of dietary concentrate level on nutrient absorption, liver metabolism, and urea kinetics of beef steers fed isonitrogenous and isoenergetic diets.

Six multicatheterized beef steers (421 +/- 21 kg BW) were used to predict the effect of dietary concentrate level on blood flow and net flux of urea and other metabolites across splanchnic tissues. Diets ranged from 0% (switchgrass hay) to 90% concentrate (10% switchgrass hay, 89% cracked corn, 1% urea). Daily DMI varied from 8.01 to 5.34 kg/d. Nitrogen intake (99 g/d) and calculated ME intake (16.8 Mcal/d) were equal among diets. As dietary concentrate increased from 0 to 90%, liver blood flow decreased from 850 to 795 L/h, portal-drained visceral (PDV) blood flow decreased from 750 to 620 L/h, and mesenteric-drained visceral (MDV) blood flow decreased from 270 to 250 L/h. Liver release of urea N was 94 mmol/h when dietary concentrate was less than 20%, then increased to 146 mmol/h at 55% concentrate. Urinary excretion of urea N was 13 mmol/h or less when dietary concentrate was 20% or less, increased to 53 mmol/h at 55% concentrate, then continued to increase to 76 mmol/h at 90% concentrate. Transfer of urea N to PDV ranged from 71 to 91 mmol/h and transfer to MDV ranged from 0 to 10 mmol/h among diets. As dietary concentrate increased from 27 to 63%, VFA release by PDV decreased, net MDV and splanchnic release of glucose increased, and splanchnic tissues switched from net uptake to net release of L-lactate. Net PDV release or liver removal of ammonia or alpha-amino N and net liver release of glucose were not affected. We conclude that the liver responded to changes in the percentage of dietary concentrate by altering urea production and by altering the role of lactate in intermediary metabolism.

Effect of Mesenteric Vein Infusion of Propionate on Splanchnic Metabolism in Primiparous Holstein Cows

Our objective was to assess the effects of increased propionate supply on gut and liver function in lactating cows. Four multicatheterized, primiparous cows (30.4±.5 kg/d of milk) were fed for ad libitum intake a diet of 50% alfalfa hay and 50% concentrate (20.6±1.9 kg/d of DM, 226±21 MJ/d of metabolizable energy, and 611±56 g/d of N). Each cow received intramesenteric infusions of NaCl (control) or Na-propionate (150 mmol/h of a 2.5 M solution) in a reversal design. After 72h of infusion, blood flow (by indicator dilution) and net flux (venoarterial differences multiplied by blood flow) were measured across portal-drained viscera and the liver. Energy supply from feed consumed and from infusion was similar between treatments. Energy that was excreted as milk decreased with propionate infusion. Propionate infusion increased arterial concentration of propionate; decreased absorption of acetate, butyrate, and valerate; and decreased hepatic removal of L-lactate, butyrate, valerate, NEFA, and oxygen. Propionate infusion decreased splanchnic release of glucose and increased splanchnic release of acetate and alanine. Net flux of urea, BHBA, insulin, or glucagon was unaffected by treatments. Our data show a link between a greater proportion of energy supplied as propionate and decreased energy excreted as milk. This response was associated with decreased net removal of glucogenic and ketogenic substrates by the liver and increased supply of acetate for use by peripheral tissues.

Effects of Diet Forage-to-Concentrate Ratio and Intake on Energy Metabolism in Growing Beef Heifers: Net Nutrient Metabolism by Visceral Tissues

Effects of diet forage-to-concentrate ratio and intake on metabolism of nutrients by portal-drained viscera (PDV), liver and kidneys were measured in seven growing beef heifers. Isonitrogenous pelleted diets containing approximately 75% alfalfa or 75% concentrate were fed every 2 h at two metabolizable energy intakes. Greater intake increased net PDV removal of glucose and urea nitrogen and net PDV release of NH3N, alpha-amino nitrogen (AAN), alanine and lactate. Lower net PDV release of NH3N, liver removal of NH3N and AAN and liver release of urea nitrogen accompanied lower N intake and digestion in heifers fed the 75% concentrate vs. the 75% alfalfa diet. Lower net PDV glucose removal resulted in greater total splanchnic glucose release when heifers were fed the 75% concentrate vs. the 75% alfalfa diet. In addition, net PDV, liver and total splanchnic release of beta-hydroxybutyrate (BOHB) were lower when heifers were fed the 75% concentrate vs. the 75% alfalfa diet. Greater tissue energy retention in heifers fed the 75% concentrate vs. the 75% alfalfa diet at equal metabolizable energy intake accompanied differences in net PDV metabolism of glucose, NH3N and BOHB and liver metabolism of nitrogenous compounds, BOHB and lactate.

EFFECT OF EXTRADURAL ANALGESIA ON GLUCOSE METABOLISM AND GLUCONEOGENESIS: Studies in Association with Upper Abdominal Surgery

Concentrations of glucose and gluconeogenic substrates across the splanchnic circulation were studied in 20 patients undergoing cholecystectomy with general anaesthesia. In 10 patients, general anaesthesia was administered alone, and in 10 general anaesthesia was combined with thoracic extradural analgesia. All patients received a constant i.v. infusion of glucose. Blood glucose concentration increased markedly in the general anaesthesia group in contrast to a moderate and shortlived increase in the patients given extradural analgesia, in whom the splanchnic release of glucose tended to be lower. The splanchnic uptake of glycerol was lower in the patients given extradural analgesia, while the uptake of lactate and the increase in alanine uptake was similar in both groups. Plasma catecholamine and serum cortisol concentrations were higher in the group receiving general anaesthesia alone, while serum growth hormone concentration was higher after surgery in the extradural group. The addition of extradural blockade to general anaesthesia suppresses the increase in blood glucose concentration--and this may be related to a reduced splanchnic release of glucose combined with an increased peripheral uptake.

Splanchnic uptake and release of energy substrates in the fasting baboon infant.

Estimates of splanchnic energy substrate exchange in the primate infant have been obtained using a baboon model. The splanchnic bed of the fasting baboon newborn released glucose at an estimated rate of 14.5 +/- 5.0 mumol/min X kg body weight. Splanchnic glucose release in the fasting 5-7 wk old baboon infant proceeded similarly at an estimated rate of 15.5 +/- 4.5 mumol/min X kg body weight. The principal precursors taken up by the splanchnic bed were lactate, glycerol, and alanine. Uptake of alanine correlated in a linear fashion with glucose release. Lactate was the most important precursor in both age groups. Glucose recycling through lactate is an active mechanism in the primate fetus as well as in the young of other species.

Hepatic gluconeogenesis during halothane anaesthesia in man.

It is known that hepatic gluconeogenesis from lactate and aminoacids is inhibited by halothane in in vitro studies on isolated, perfused livers. In the present work, the effect of halothane anaesthesia on hepatic gluconeogenesis was studied in three volunteers during a constant amino-acid infusion and compared with three control subjects who did not receive any halothane during the amino-acid infusion. Prior to the investigation, all the subjects were on a carbohydrate-poor diet in order to deplete hepatic glucogen stores. During the investigation, hepatic gluconeogenesis was stimulated by a constant amino-acid infusion which caused a slight rise in total hepatic blood flow (THBF), a marked increase in splanchnic oxygen consumption and oxygen extraction, elevation in blood glucose and urea levels and in splanchnic glucose and urea releases. Halothane anaesthesia administered during continued amino-acid infusion caused a reduction in THBF to sub-control values, while the increased oxygen consumption was only slightly reduced, thereby further increasing splanchnic oxygen extraction. Blood glucose and urea levels of the anaesthetized subjects were consistent with those of the control subjects. Splanchnic release of glucose was reduced almost to control values during halothane. However, the release of urea was only slightly reduced. It is concluded that the stimulating effect on hepatic gluconeogenesis caused by the amino-acid infusion was inhibited during halothane anaesthesia, while metabolization of the amino-acids, other than through gluconeogenesis, proceeded without any major changes.

Interrelationship between splanchnic and leg exchange of glucose and other blood‐borne energy metabolites during abdominal surgical trauma

Summary. In eight patients undergoing cholecystectomy, measurements of leg blood flow, splanchnic blood flow and arterio‐venous differences in oxygen, glucose, lactate, pyruvate, glycerol, 3‐hydroxybutyrate and alanine were made. Splanchnic glucose release averaged 1 1 mmol/min. The uptake of glucose into leg tissue was low. The rise in arterial glucose concentration was about I mmol/h during surgery. At the end of surgery splanchnic oxygen uptake was increased by 70% and the alanine uptake into the same region was comparable to that described in patients with septic complications of surgery. The plasma insulin concentration was low compared with the arterial glucose level.The data suggest that during abdominal surgery (a) increase in arterial glucose concentration can be fully accounted for by slightly increased splanchnic glucose release and a low peripheral utilization; (b) release of gluconeogenic substrates from peripheral tissues is balanced by splanchnic uptake; (c) disturbed relation between glucose and insulin, enhanced gluconeogenesis, increased splanchnic oxygen uptake and fat‐mobilizing lipolysis are in accordance with a raised sympatho‐adrenergic activity.

Splanchnic glucose and muscle glycogen metabolism after glucose feeding during postexercise recovery.

Glucose (100 g) was ingested 15 min after bicycle exercise until exhaustion at a work load corresponding to 70% of maximal uptake (series 1), 14--15 h after an identical exercise period, no food being taken in the interval (series 2), and by nonexercised control subjects. Splanchnic glucose output in the exercised groups rose to values 50--300% greater than in controls, amounting to (over 135 min) 59 +/- 5 g in series 1 and 58 +/- 6 in series 2 compared to 28 +/- 6 in controls. The glycogen concentration of quadriceps muscle in series 1 was 65 +/- 2 mmol glycosyl U/kg wet wt before exercise, 16 +/- 13 at the end of work, and 32 +/- 4 at 135 min after glucose ingestion. In series 2, muscle glycogen concentration was 20 +/- 3 immediately after exercise and rose to 44 +/- 5 over the ensuing 14--15 h in spite of continued fasting. It rose to 56 +/- 3 at 135 min after glucose loading. Repletion of leg muscle glycogen after glucose feeding could account for 50--66% of total splanchnic glucose release. It is concluded that during postexercise recovery, a greater proportion of an oral glucose load escapes hepatic retention, allowing repletion of muscle glycogen to take precedence over hepatic glycogen repletion.

Human splanchnic metabolism during diabetic ketoacidosis

Splanchnic exchange rates of glucose, acetoacetate, β-hydroxybutyrate, lactate, pyruvate, glycerol, alanine, glutamine, glutamate, free fatty acids, and triglycerides were measured in eight patients during moderate to severe diabetic ketoacidosis. Their arterial glucose concentration was 20.68 (9.80–52.79) μmole/liter and total ketone-body concentration was 10.38 (6.04–15.81) mmole/liter. Net splanchnic glucose release was 0.77 (0.09–2.44) mmole/min. Gluconeogenesis accounted for about one-half of net splanchnic glucose release, assuming quantitative conversion of net splanchnic extracted lactate, pyruvate, glycerol, alanine, and α-ketoglutarate equivalents to glucose. Net splanchnic free fatty acid extraction was 0.24 (0.09–0.52) mmole/min. There was a positive correlation between free fatty acid uptake and ketone-body release. Net splanchnic acetoacetate release was 0.50 (0.05–0.92) mmole/min and β-hydroxybutyrate release was 0.35 (−0.16 to 0.84) mmole/min. Total ketone-body release was 0.85 (0.37–1.61) mmole/min. The wide ranges of net splanchnic glucose and ketone-body production rates show the heterogeneous characteristics of the diabetic patient in ketoacidosis. It is concluded that the hyperglycemia and hyperketonemia of diabetic ketoacidosis is due to the lack of reciprocity among rates of hepatic glycogenolysis, gluconeogenesis, and ketogenesis resulting in inappropriate net splanchnic release of glucose and ketone bodies.

Renal glucose, free fatty acid, and ketone body metabolism in the unanesthetized sheep.

ARTICLESRenal glucose, free fatty acid, and ketone body metabolism in the unanesthetized sheepCF Kaufman, and EN BergmanCF KaufmanSearch for more papers by this author, and EN BergmanSearch for more papers by this authorPublished Online:01 Oct 1971https://doi.org/10.1152/ajplegacy.1971.221.4.967MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByDifferent levels of response to heat stress in dairy goatsSmall Ruminant Research, Vol. 121, No. 1Effect of amino acid or casein supply on whole-body, splanchnic, and mammary glucose kinetics in lactating dairy cowsJournal of Dairy Science, Vol. 94, No. 11Lipids and KetonesChanges in Net Portal Nutrient Flux in Response to Weaning Transition and Ionophore Supplementation in Dairy CalvesJournal of Dairy Science, Vol. 90, No. 3Intraruminal propionate supplementation modifies hindlimb energy metabolism without changing the splanchnic release of glucose in growing lambs9 March 2007 | British Journal of Nutrition, Vol. 89, No. 1Lipids and KetonesIncreased ketone utilization by the kidney reduces renal lactate uptake but does not affect tubular sodium reabsorptionMetabolism, Vol. 42, No. 6Effects of Diet Forage-to-Concentrate Ratio and Intake on Energy Metabolism in Growing Beef Heifers: Net Nutrient Metabolism by Visceral TissuesThe Journal of Nutrition, Vol. 121, No. 7In Vitro Production of β;-Hydroxybutyrate from 1,3-Butanediof by Bovine Liver, Rumen Mucosa, and KidneyJournal of Dairy Science, Vol. 73, No. 3Techniques for Measuring Blood Flow in Splanchnic Tissues of CattleJournal of Dairy Science, Vol. 72, No. 6Autoregulation of Alimentary and Hepatic Ketogenesis in SheepJournal of Dairy Science, Vol. 69, No. 5Relationship of deranged energy metabolism in liver and kidney to arterial ketone body ratio following liver ischemia in ratsThe Japanese Journal of Surgery, Vol. 14, No. 1Metabolism of ketone bodies in pregnant sheep9 March 2007 | British Journal of Nutrition, Vol. 48, No. 3Glutamate interconversions and glucogenicity in the sheepR. N. Heitmann, and E. N. Bergman1 December 1981 | American Journal of Physiology-Endocrinology and Metabolism, Vol. 241, No. 6Inhalation pharmacokinetics based on gas uptake studiesArchives of Toxicology, Vol. 47, No. 4Characteristics of the Metabolism of Carbohydrate in Ruminants Compared with other MammalsLIPID METABOLISM IN LIVER AND SELECTED TISSUES AND IN THE WHOLE BODY OF RUMINANT ANIMALSEffects of an intravenous infusion of hydrochloric acid on renal function in sheepResearch in Veterinary Science, Vol. 28, No. 3Renal gluconeogenesis in pregnant and non-pregnant sheepInternational Journal of Biochemistry, Vol. 11, No. 3-4Oxidation of butyrate to ketone bodies and CO2 in the rumen epithelium, liver, kidney, heart and lung of camel (Camelus dromedarius), sheep (Ovis aries) and goat (Carpa hircus)Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, Vol. 65, No. 4Specific Methods for the Determination of Radioactivity in D-(—)-3-Hydroxybutyrate in Blood Plasma29 August 2016 | Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, Vol. 16, No. 1-6Gluconeogenesis in Cattle: Significance and MethodologyJournal of Dairy Science, Vol. 60, No. 1Cellular Gluconeogenesis by Lactating Bovine Mammary TissueJournal of Dairy Science, Vol. 59, No. 1Production of CO2 by the Intact Functioning Kidney of the DogMedical Clinics of North America, Vol. 59, No. 3Renal conservation of ketone bodies during starvationMetabolism, Vol. 24, No. 1Effects of high and low protein diets on sheep renal function and metabolismKidney International, Vol. 4, No. 3Studies on the control of gluconeogenesis in sheep: effect of propionate, casein and butyrate infusions24 July 2007 | British Journal of Nutrition, Vol. 29, No. 2Radioactive microsphere measurement of cardiac output and regional tissue blood flow in the sheepPfl�gers Archiv European Journal of Physiology, Vol. 344, No. 2 More from this issue > Volume 221Issue 4October 1971Pages 967-972 Copyright & PermissionsCopyright © 1971 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1971.221.4.967PubMed5111265History Published online 1 October 1971 Published in print 1 October 1971 Metrics