Effect of glutamine on water and sodium absorption in human jejunum at baseline and during PGE1-induced secretion

2005 ◽  
Vol 98 (6) ◽  
pp. 2163-2168 ◽  
Author(s):  
Moïse Coëffier ◽  
Bernadette Hecketsweiler ◽  
Philippe Hecketsweiler ◽  
Pierre Déchelotte
Keyword(s):  
Steady State ◽  
Nutritional Support ◽  
Random Order ◽  
Metabolic Effects ◽  
Secretory Diarrhea ◽  
Sodium Absorption ◽  
Lumen Tube ◽  
Polyethylene Glycol 4000 ◽  
Jejunal Absorption ◽  
Threefold Increase

Glutamine, a major fuel for enterocytes, stimulates water and sodium absorption in animal models of secretory diarrhea, but data in humans are still limited. The aim of this study was to investigate the effect of glutamine on jejunal absorption during hypersecretion in humans. In six healthy adults, the effects of glutamine on jejunal absorption were assessed with a triple-lumen tube on two occasions, at baseline and during PGE1-induced hypersecretion (0.1 μg·kg−1·min−1) in a random order. Isoosmolar solutions containing polyethylene glycol 4000 as nonabsorbable marker were infused in the jejunum at 10 ml/min over 1-h periods: saline (sodium chloride 308 mmol/l), glucose-mannitol 45:45 mM, glucose 90 mM, alanine-glucose 45:45 mM, glutamine-glucose 45:45 mM, and glutamine 90 mM. Net absorptive and secretory fluxes were measured at steady state. At baseline, glutamine- and alanine-containing solutions induced a threefold increase of water and sodium absorption ( P < 0.05); 90 mM glutamine stimulated water absorption more than 90 mM glucose (3.6 ± 0.6 vs. 1.9 ± 0.3 ml·min−1·30 cm−1, P < 0.05). PGE1-induced hypersecretion was reduced ( P < 0.05) by solutions of alanine-glucose, glutamine-glucose, and glutamine 90 mM ( P < 0.05) and reversed to absorption by alanine-glucose and glutamine-glucose. Glutamine and alanine absorption was nearly complete and was not influenced by PGE1. In conclusion, glutamine stimulates water and electrolyte absorption in human jejunum, even during experimental hypersecretion. In addition to the metabolic effects of glutamine, these results support the evaluation of glutamine-containing solutions for the rehydration and the nutritional support of patients with secretory diarrhea.

Effect of Intraluminal Concentrations on the Impairment of Glycine Absorption by Glucose in the Human Jejunum

1972 ◽  
Vol 42 (5) ◽  
pp. 525-534 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Clinical Evidence ◽  
Random Order ◽  
Glucose Absorption ◽  
Double Lumen Tube ◽  
Three Solutions ◽  
Lumen Tube ◽  
Jejunal Absorption ◽  
Jejunal Segment ◽  
The Mean ◽  
African Patients

1. To investigate the effect of different intraluminal concentrations on the mutual inhibitive effect of glycine and glucose on their jejunal absorption rates, eighteen convalescent Zambian African patients who had no clinical evidence of intestinal disease or of malnutrition were given constant intrajejunal infusions with those solutes either together or alone. A double-lumen tube perfusion system was used, and three solutions containing (A) glycine, (B) glycine and glucose, and (C) glucose, all of which were rendered iso-osmotic with sodium chloride, were perfused in random order at 12·0 ml/min. The concentration of glycine in the perfusing fluid was either 10 or 20 mm, and that of glucose either 100, 200 or 280 mm. By reference to polyethylene glycol 4000, the absorption rates of the solutes and water were calculated for a 30 cm jejunal segment. 2. At a glucose concentration of 200 or 280 mm, but not 100 mm, the mean rate of glycine absorption was decreased by approx. 30%. Glucose absorption rates were not significantly altered by glycine. 3. These observations, taken in conjunction with those from a previous investigation, are consistent with the view that there are two mechanisms for the jejunal absorption of glycine in man, one of which is inhibited by glucose at high intraluminal concentration.

Potassium conductance in rabbit esophageal epithelium

1993 ◽  
Vol 265 (1) ◽  
pp. G28-G34 ◽  
Author(s):  
W. E. Khalbuss ◽  
R. Alkiek ◽  
C. G. Marousis ◽  
R. C. Orlando
Keyword(s):  
Steady State ◽  
Epithelial Cells ◽  
Short Circuit ◽  
Basolateral Membrane ◽  
Potassium Conductance ◽  
Short Circuit Current ◽  
Sodium Absorption ◽  
High K ◽  
Esophageal Epithelial Cells ◽  
Apical Membranes

K+ conductance in apical and basolateral cell membranes of rabbit esophageal epithelial cells was investigated within intact epithelium by impalement with conventional microelectrodes from luminal or serosal sides. Under steady-state conditions, K+ conductance was demonstrated in basolateral, but not apical, membranes by showing 1) membrane depolarization upon exposure to either solutions high in K+ (20-65 mM) or containing Ba2+, tetraethylammonium, or quinine, and 2) a resistance ratio that increased on exposure to high K+ solution and decreased on exposure to Ba2+, quinine, and tetraethylammonium. From exposures to high K+, the apparent K+ transference number and electromotive force generated at the basolateral membrane were calculated and found to be 0.42 +/- 0.01 and -83 +/- 3 mV, respectively. Furthermore, basolateral K+ conductance was shown to be important for maintaining resting net transepithelial Na+ absorption in that high K+ or barium inhibited the transepithelial potential difference and short-circuit current of Ussing-chambered epithelia. We conclude that under steady-state conditions the basolateral, but not apical, membranes of esophageal epithelial cells contain a K(+)-conductive pathway and that this pathway is important for active sodium absorption.

scholarly journals Breaking up prolonged sitting time with walking does not affect appetite or gut hormone concentrations but does induce an energy deficit and suppresses postprandial glycaemia in sedentary adults

2016 ◽  
Vol 41 (3) ◽  
pp. 324-331 ◽  
Author(s):  
Daniel P. Bailey ◽  
David R. Broom ◽  
Bryna C.R. Chrismas ◽  
Lee Taylor ◽  
Edward Flynn ◽  
...  
Keyword(s):  
Energy Intake ◽  
Peptide Yy ◽  
Random Order ◽  
Sitting Time ◽  
Metabolic Effects ◽  
Energy Deficit ◽  
Moderate Intensity ◽  
Prolonged Sitting ◽  
Gut Hormone ◽  
Ad Libitum

Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study. Thirteen sedentary (7 female) participants undertook three 5-h trials in random order: (i) uninterrupted sitting (SIT), (ii) seated with 2-min bouts of light-intensity walking every 20 min (SIT + LA), and (iii) seated with 2-min bouts of moderate-intensity walking every 20 min (SIT + MA). A standardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial. Subjective appetite ratings and plasma acylated ghrelin, peptide YY, insulin, and glucose were measured at regular intervals. Area under the curve (AUC) was calculated for each variable. AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting (linear mixed modelling: p > 0.05). Glucose AUC was lower in SIT + MA than in SIT + LA (p = 0.004) and SIT (p = 0.055). There was no difference in absolute ad libitum energy intake between conditions (p > 0.05); however, relative energy intake was lower in SIT + LA (39%; p = 0.011) and SIT + MA (120%; p < 0.001) than in SIT. In conclusion, breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period. Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal.

The effect of three osmotic agents on free proline and amino acid pools in Atriplex canescens and Hilaria jamesii

1987 ◽  
Vol 65 (4) ◽  
pp. 799-801 ◽  
Author(s):  
William A. Cress ◽  
Gordon V. Johnson
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Plant Species ◽  
Arid Region ◽  
Proline Content ◽  
Metabolic Effects ◽  
Free Proline ◽  
Atriplex Canescens ◽  
Polyethylene Glycol 4000 ◽  
Osmotic Agents

Three commonly used osmotic agents, mannitol, sucrose, and polyethylene glycol 4000, were used to simulate water stress in two arid region plant species, Hilaria jamesii (Torr.) Benth. and Atriplex canescens (Pursh) Nutt. Large amounts of mannitol (300–1400 μmol/g dry wt.) and sucrose (450–660 μmol/g dry wt.) were absorbed by both plant species, while insignificant amounts of polyethylene glycol 4000 were absorbed. During osmotic stress, Hilaria jamesii accumulated large quantities of proline, while A. canescens accumulated only a small amount. Shoot proline content of both species varied significantly with the osmotic agents used to simulate water stress. These results indicate that use of absorbable osmotic agents to simulate water stress may have important metabolic effects on the concentration of free proline and other metabolites.

111 Validation of the Indicator Amino Acid Oxidation Technique in the Domestic Cat

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 61-61
Author(s):  
Julia Guazzelli Pezzali ◽  
Mahroukh Rafii ◽  
Glenda Courtney-Martin ◽  
Anna-Kate Shoveller
Keyword(s):  
Steady State ◽  
Plasma Concentrations ◽  
Dietary Treatment ◽  
Random Order ◽  
Domestic Cat ◽  
Acid Oxidation ◽  
Linear Regression Models ◽  
Deficient Diet ◽  
Steady State Kinetics ◽  
Adult Cats

Abstract There is a lack of data on the minimum Met or total sulfur AA (SAA) requirements for adult cats. Non-invasive and precise techniques, such as indicator AA oxidation (IAAO) can be used for these purposes. This pilot study aimed to validate the IAAO technique in cats and investigate the effect of dietary Met concentrations and sources on fasted plasma SAA concentrations. Six cats were fed three experimental diets in random order: Met-deficient diet (BASAL; 0.23% Met+Cys-DM) and two Met-sufficient diets in which either DL-Met (DLM) or Met-hydroxy-analogue (MHA) were supplemented, respectively, on an equimolar basis to meet the total SAA requirement (0.34%-DM). After 2d diet adaptation, IAAO studies were performed. Cats were offered 13 ½-hourly small meals. The 6th meal contained a priming dose (4.8 mg/kg-BW) of L-[1-13C]-Phe and the remaining meals the constant dose (1.04 mg/kg-BW). Breath samples were collected ½-hourly to measure 13CO2 enrichment. The following morning after an 16hr fast, blood samples were collected. Isotopic steady-state was evaluated through linear regression models. Plasma AA data were analyzed using PROC GLIMMIX procedure in SAS (Version 9.4). Met concentrations tended to be higher in cats fed DLM compared to BAS (P = 0.0877), but similar to those fed MHA (P &gt; 0.05). Total cysteine plasma concentrations were similar between treatments (P &gt; 0.05). Cats fed BAS had greater concentrations of plasma HCys compared to DLM and MHA (P = 0.0093). Cats did not reach isotopic steady-state in atom percent excess (P &gt;0.05) regardless of the dietary treatment provided. Non-steady-state kinetics models are under development to predict 13CO2 flux. This study indicates that the short-term feeding of a Met-deficient diet in cats results in greater plasma Hcys and a tendency for lower plasma Met concentrations. A higher prime dose of L-[1-13C]-Phe is warranted to achieve isotopic steady-state and successfully apply the IAAO to estimate AA requirements.

scholarly journals Steady-State Kinetic Analysis of Phosphotransacetylase from Methanosarcina thermophila

2006 ◽  
Vol 188 (3) ◽  
pp. 1155-1158 ◽  
Author(s):  
Sarah H. Lawrence ◽  
James G. Ferry
Keyword(s):  
Steady State ◽  
Kinetic Analysis ◽  
Random Order ◽  
Kinetic Mechanism ◽  
Methanosarcina Thermophila ◽  
Steady State Kinetic ◽  
Ping Pong ◽  
Acetyl Group ◽  
State Kinetic ◽  
Reversible Transfer

ABSTRACT Phosphotransacetylase (EC 2.3.1.8) catalyzes the reversible transfer of the acetyl group from acetyl phosphate to coenzyme A (CoA), forming acetyl-CoA and inorganic phosphate. A steady-state kinetic analysis of the phosphotransacetylase from Methanosarcina thermophila indicated that there is a ternary complex kinetic mechanism rather than a ping-pong kinetic mechanism. Additionally, inhibition patterns of products and a nonreactive substrate analog suggested that the substrates bind to the enzyme in a random order. Dynamic light scattering revealed that the enzyme is dimeric in solution.

scholarly journals Cation-Anion Balance during Potassium and Sodium Absorption by Barley Roots

1963 ◽  
Vol 46 (3) ◽  
pp. 369-386 ◽  
Author(s):  
P. C. Jackson ◽  
H. R. Adams
Keyword(s):  
Steady State ◽  
External Solution ◽  
Potassium Ion ◽  
Sodium Ion ◽  
The Other ◽  
Sodium Absorption ◽  
Specific Rate ◽  
Sodium Ions ◽  
Ion Absorption ◽  
Rate Limiting

Steady-state rates of potassium ion and sodium ion absorption by excised barley roots accompanied by various anions were compared with the rates of anion absorption and the concomitant H+ and base release by the roots. The cation absorption rates were found to be independent of the identities, concentrations, and rates of absorption of the anions of the external solution, including bicarbonate. Absorption of the anion of the salt plus bicarbonate could not account for the cation absorption. H+ is released during cation absorption and base during anion absorption. The magnitude by which one or the other predominates depends on the relative rates of anion and cation absorption under various conditions of pH, cation and anion concentration, and inhibitor concentrations. The conclusion is that potassium and sodium ions are absorbed independently of the anions of the absorption solution in exchange for H+, while anions are exchanged for a base. The H+ release reflects a specificity between K+ and Na+ absorption such that it appears to be H+ exchanged in the specific rate-limiting reactions of the cation absorption.

scholarly journals Metabolic Effects of Oral Versus Transdermal Estrogen in Growth Hormone-Treated Girls with Turner Syndrome

2007 ◽  
Vol 92 (11) ◽  
pp. 4154-4160 ◽  
Author(s):  
Nelly Mauras ◽  
Dorothy Shulman ◽  
Helen Y. Hsiang ◽  
Prabhakaran Balagopal ◽  
Susan Welch
Keyword(s):  
Turner Syndrome ◽  
Protein Turnover ◽  
Plasma Lipids ◽  
Random Order ◽  
Metabolic Effects ◽  
Whole Body ◽  
Dual Emission ◽  
Body Protein ◽  
Oxidation Rates ◽  
Igf I

Abstract Background: Transdermal (TD) estrogen is often preferred over the oral route in postmenopausal and GH-deficient women taking estrogen, but this has not been studied in detail in girls. Objective: Our objective was to study the metabolic effects of oral vs. TD estrogen in GH-treated girls with Turner syndrome. Design and Methods: Eleven girls with Turner syndrome, mean age 13.4 ± 0.5 (se) yr, on GH for at least 6 months were recruited. Studies included [13C]leucine and d5-glycerol infusions, indirect calorimetry, dual-emission x-ray absorptiometry, and hormone and substrate measurements. They received, in random order, 17β-estradiol orally (0.5, 1, and 2 mg for 2 wk each) and TD (0.025, 0.0375, and 0.05 mg for 2 wk each), and studies were repeated after each 6-wk course with 4 wk washout in between. Results: Rates of whole-body protein turnover, oxidation and synthesis, lipolysis, lipid and carbohydrate oxidation, and resting energy expenditure were unaffected by either form of estrogen; nor were lipids, insulin, and fibrinogen concentrations affected. Plasma IGF-I concentrations did not change clinically significantly with either form of estrogen, despite higher estrogen concentrations after oral estrogen. Estradiol concentrations did not correlate with any variables measured. Conclusions: In GH-treated girls with Turner syndrome, neither oral nor TD estrogen adversely affected rates of protein turnover, lipolysis, and lipid oxidation rates or plasma lipids, fibrinogen, or fasting insulin concentrations. There was no clinically significant change in IGF-I concentrations after either form of estrogen. In aggregate, these data suggest that the route of delivery of estrogen does not adversely affect these metabolic effects of GH in young girls with Turner syndrome.

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