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Jeschke MG, Mlcak RP, Finnerty CC, Norbury WB, Gauglitz GG, Kulp GA, Herndon DN. Burn size determines the inflammatory and hypermetabolic response. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 11:R90. [PMID: 17716366 PMCID: PMC2206482 DOI: 10.1186/cc6102] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/20/2007] [Accepted: 08/23/2007] [Indexed: 01/04/2023]
Abstract
Background Increased burn size leads to increased mortality of burned patients. Whether mortality is due to inflammation, hypermetabolism or other pathophysiologic contributing factors is not entirely determined. The purpose of the present study was to determine in a large prospective clinical trial whether different burn sizes are associated with differences in inflammation, body composition, protein synthesis, or organ function. Methods Pediatric burned patients were divided into four burn size groups: <40% total body surface area (TBSA) burn, 40–59% TBSA burn, 60–79% TBSA burn, and >80% TBSA burn. Demographic and clinical data, hypermetabolism, the inflammatory response, body composition, the muscle protein net balance, serum and urine hormones and proteins, and cardiac function and changes in liver size were determined. Results One hundred and eighty-nine pediatric patients of similar age and gender distribution were included in the study (<40% TBSA burn, n = 43; 40–59% TBSA burn, n = 79; 60–79% TBSA burn, n = 46; >80% TBSA burn, n = 21). Patients with larger burns had more operations, a greater incidence of infections and sepsis, and higher mortality rates compared with the other groups (P < 0.05). The percentage predicted resting energy expenditure was highest in the >80% TBSA group, followed by the 60–79% TBSA burn group (P < 0.05). Children with >80% burns lost the most body weight, lean body mass, muscle protein and bone mineral content (P < 0.05). The urine cortisol concentration was highest in the 80–99% and 60–79% TBSA burn groups, associated with significant myocardial depression and increased change in liver size (P < 0.05). The cytokine profile showed distinct differences in expression of IL-8, TNF, IL-6, IL-12p70, monocyte chemoattractant protein-1 and granulocyte–macrophage colony-stimulating factor (P < 0.05). Conclusion Morbidity and mortality in burned patients is burn size dependent, starts at a 60% TBSA burn and is due to an increased hypermetabolic and inflammatory reaction, along with impaired cardiac function.
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Affiliation(s)
- Marc G Jeschke
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
- Department of Surgery, University Texas Medical Branch, Galveston, TX, 77550 USA
| | - Ronald P Mlcak
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
| | - Celeste C Finnerty
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
- Department of Surgery, University Texas Medical Branch, Galveston, TX, 77550 USA
| | - William B Norbury
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
| | - Gerd G Gauglitz
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
- Department of Surgery, University Texas Medical Branch, Galveston, TX, 77550 USA
| | - Gabriela A Kulp
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
| | - David N Herndon
- Shriners Hospitals for Children, 815 Market Street, Galveston, TX 77550, USA
- Department of Surgery, University Texas Medical Branch, Galveston, TX, 77550 USA
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Ericsson A, Hamark B, Jansson N, Johansson BR, Powell TL, Jansson T. Hormonal regulation of glucose and system A amino acid transport in first trimester placental villous fragments. Am J Physiol Regul Integr Comp Physiol 2004; 288:R656-62. [PMID: 15539610 DOI: 10.1152/ajpregu.00407.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alterations in placental nutrient transfer have been implicated in fetal growth abnormalities. In pregnancies complicated by diabetes and accelerated fetal growth, upregulations of glucose transporter 1 (GLUT1) and amino acid transporter system A have been shown in the syncytiotrophoblast of term placenta. In contrast, intrauterine growth restriction is associated with a downregulation of placental system A transporters. However, underlying mechanisms of transporter regulation are poorly understood, particularly in early pregnancy. In this study, hormonal regulation of placental glucose and system A transporters was investigated. The uptake of 3-O-[methyl-(14)C]-d-glucose was studied in villous fragments isolated from first trimester (6-13 wk of gestation) and term human placenta. Villous fragments were incubated in buffer containing insulin, leptin, cortisol, growth hormone (GH), prolactin, IGF-I, or under hypo/hyperglycemic conditions for 1 h. Subsequently, 3-O-[methyl-(14)C]-D-glucose uptake was measured with and without phloretin for 70 s in first trimester tissue and 20 s in term tissue. Methylaminoisobutyric uptake was measured with and without Na+ for 20 min. Glucose uptake was unaltered by hormones or hypo/hyperglycemia. GH decreased system A activity by 31% in first trimester (P < 0.05). The uptake of glucose was 50% higher in term compared with first trimester fragments and increased markedly between 6 and 13 wk of gestation (P < 0.05). We conclude that placental glucose transporter activity is not regulated by short exposures to the hormones or glucose concentrations tested. In contrast to term placental villous fragments, system A activity was not regulated by insulin or leptin in first trimester but was downregulated by GH.
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Affiliation(s)
- Anette Ericsson
- Perinatal Center, Dept. of Physiology and Pharmacology, Göteborg University, Box 432, 405 30 Göteborg, Sweden.
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Carroll PV, Jackson NC, Russell-Jones DL, Treacher DF, Sönksen PH, Umpleby AM. Combined growth hormone/insulin-like growth factor I in addition to glutamine-supplemented TPN results in net protein anabolism in critical illness. Am J Physiol Endocrinol Metab 2004; 286:E151-7. [PMID: 12759221 DOI: 10.1152/ajpendo.00122.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Protein loss leading to reduced lean body mass is recognized to contribute to the high levels of morbidity and mortality seen in critical illness. This prospective, randomized, controlled study compared the effects of conventional parenteral nutrition (TPN), glutamine-supplemented (0.4 g.kg-1.day-1) TPN (TPNGLN), and TPNGLN with combined growth hormone (GH, 0.2 IU.kg-1.day-1) and IGF-I (160 microg.kg-1.day-1) on protein metabolism in critical illness. Nineteen mechanically ventilated subjects [64 +/- 3 yr, body mass index (BMI) 23.8 +/- 1.3, kg/m2] were initially studied in the fasting state (study 1) and subsequently after 3 days of nutritional with/without hormonal support (study 2). All had recently been admitted to the ICU and the majority were postemergency abdominal surgery (APACHE II 17.5 +/- 1.0). Protein metabolism was assessed using a primed constant infusion of [1-13C]leucine. Conventional TPN contained mixed amino acids, Intralipid, and 50% dextrose. TPNGLN, unlike TPN alone, resulted in an increase in plasma glutamine concentration ( approximately 50%, P < 0.05). Both TPN and TPNGLN decreased the rate of protein breakdown (TPN 15%, P < 0.002; TPNGLN 16%, P < 0.05), but during these treatments the patients remained in a net negative protein balance. Combined treatment with TPNGLN + GH/IGF-I increased plasma IGF-I levels (10.3 +/- 0.8 vs. 48.1 +/- 9.1 nmol/l, study 1 vs. study 2, P < 0.05), and in contrast to therapy with nutrition alone, resulted in net protein gain (-0.75 +/- 0.14 vs. 0.33 +/- 0.12 g protein.kg-1.day-1, study 1 vs. study 2, P < 0.05). Therapy with GH/IGF-I + TPNGLN, unlike nutrition alone, resulted in net positive protein balance in a group of critically ill patients.
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Affiliation(s)
- Paul V Carroll
- Department of Diabetes & Endocrinology, St. Thomas' Hospital, London SE1 7EH, UK.
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Ljungmann K, Grofte T, Kissmeyer-Nielsen P, Flyvbjerg A, Vilstrup H, Tygstrup N, Laurberg S. GH decreases hepatic amino acid degradation after small bowel resection in rats without enhancing bowel adaptation. Am J Physiol Gastrointest Liver Physiol 2000; 279:G700-6. [PMID: 11005756 DOI: 10.1152/ajpgi.2000.279.4.g700] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Growth hormone (GH) treatment in short bowel syndrome is controversial, and the mechanisms of a possible positive effect remain to be elucidated. Rats were randomly subjected to either an 80% jejunoileal resection or sham operation and were given either placebo (NaCl) or biosynthetic rat GH (brGH). The in vivo capacity of urea nitrogen synthesis (CUNS) and the expression of urea cycle enzymes were measured and related to changes in body weight and adaptive growth in ileal segments on days 7 and 14. Ileal segments were examined by unbiased stereological techniques. brGH treatment decreased CUNS among the resected rats by 19% (P<0.05) and 36% (P<0.05) on days 7 and 14, respectively. The mRNA levels of urea cycle enzyme genes were not influenced by brGH treatment. brGH treatment did not increase the adaptive growth in the ileal segments. In conclusion, we found that GH treatment decreased the accelerated postoperative hepatic amino acid degradation in experimental short bowel syndrome without enhancing the morphological intestinal adaptation.
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Affiliation(s)
- K Ljungmann
- Surgical Research Unit, Department of Surgery L, University Hospital of Aarhus, DK-8000 Aarhus C, Denmark.
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Matthews JC, Beveridge MJ, Dialynas E, Bartke A, Kilberg MS, Novak DA. Placental anionic and cationic amino acid transporter expression in growth hormone overexpressing and null IGF-II or null IGF-I receptor mice. Placenta 1999; 20:639-50. [PMID: 10527818 DOI: 10.1053/plac.1999.0421] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The role of growth hormone (GH), insulin-like growth factor (IGF)-II and the IGF-I receptor (IGF-Ir) in the regulation of the in vivo expression of Na(+)-coupled anionic [System X-AG; GLAST1 (EAAT1), GLT1 (EAAT2), EAAC1 (EAAT3), EAAT4; where the human homologues of amino acid transport proteins first cloned in the rat are given in parentheses] and Na(+)-independent cationic (System y(+);CAT1) amino acid transport proteins was evaluated by comparing transporter expression in day 17 placentae of mice that overexpressed bovine GH (GH+) or that carried null gene mutations for IGF-II or IGF-Ir. Northern analysis revealed no apparent difference in the mRNA content of GLAST1 (EAAT1), EAAC1 (EAAT3), or EAAT4, in homogenates of GH+ placentae, but levels of GLT1 (EAAT2) and CAT1 mRNA were increased. Immunoblot analysis revealed that whole-placental steady-state GLAST1 (EAAT1), EAAC1 (EAAT3), and EAAT4 protein levels were not affected by GH+, whereas GLT1 (EAAT2) levels were increased. Immunohistochemical analysis showed that the cell-specific expression of the anionic and CAT1 transporters was not affected by overexpression of GH. Similar analyses of null IGF-II placentae demonstrated increases in GLAST1 (EAAT1), EAAT4 and CAT1 mRNAs. Parallel immunoblot analysis demonstrated decreased expression of GLT1 (EAAT2), GLAST1 (EAAT1) and EAAC1 (EAAT3) protein, but an increased expression of EAAT4. In null IGF-II and IGF-Ir placentae, however, GLT1 (EAAT2) and EAAC1 (EAAT3) protein content was decreased in junctional zone cells, whereas CAT1 content was increased in junctional and labyrinth zone cells. These data indicate that an excess level of GH stimulates GLT1 (EAAT2) expression and that a normal level of IGF-II is required for typical expression of GLT1 (EAAT2), GLAST1 (EAAT1) and EAAC1 (EAAT3), but that IGF-II downregulates the expression of EAAT4 and CAT1.
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Affiliation(s)
- J C Matthews
- Department of Animal Sciences, University of Kentucky, Lexington, 40546, USA
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Barle H, Essén P, Nyberg B, Olivecrona H, Tally M, McNurlan MA, Wernerman J, Garlick PJ. Depression of liver protein synthesis during surgery is prevented by growth hormone. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:E620-7. [PMID: 10198296 DOI: 10.1152/ajpendo.1999.276.4.e620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was undertaken to elucidate the specific effects of growth hormone (GH) on liver protein metabolism in humans during surgery. Otherwise healthy patients scheduled for elective laparoscopic cholecystectomy were randomized into controls (n = 9) or pretreatment with 12 units of GH for 1 day (GH 1, n = 9) or daily for 5 days (GH 5, n = 10). The fractional synthesis rate of liver proteins, as assessed by flooding with [2H5]phenylalanine, was higher in the GH 5 group (22.0 +/- 6.9%/day, mean +/- SD, P < 0.05) than in the control (16.1 +/- 3.1%/day) and GH 1 (16.5 +/- 5.5%/day) groups. During surgery, the fraction of polyribosomes in the liver, as assessed by ribosome analysis, decreased in the control group by approximately 12% (P < 0.01) but did not decrease in the GH-treated groups. In addition, the concentrations of the essential amino acids and aspartate in the liver decreased in response to GH treatment. In conclusion, GH pretreatment decreases hepatic free amino acid concentrations and preserves liver protein synthesis during surgery.
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Affiliation(s)
- H Barle
- Department of Anesthesiology and Intensive Care, Huddinge University Hospital, S-141 86 Huddinge, Sweden.
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8
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Tang YW. The effect of burn subeschar tissue fluid on skeletal muscle and hepatic amino acid uptake in an experimental system in vitro. Burns 1999; 25:137-44. [PMID: 10208388 DOI: 10.1016/s0305-4179(98)00146-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Burn injury is associated with major metabolic disturbances. Many factors or mediators are responsible for post-burn metabolic changes. The present study was designed to test the role of interstitial edema fluid from burn eschar in regulating amino acid transport into hepatic and muscle tissue. Subeschar tissue fluid (SEF) was collected from just under the full thickness burn area. Amino acid transport, determined as the uptake of [3H]-alpha-aminoisobutyric acid by incubated soleus muscles or liver slices in vitro, was reduced after the addition of subeschar tissue fluid. The suppression was more marked with fluids taken from patients with a large burn area. Significant findings were noted when the total surface burn area was more than 70%. There were significant differences in the SEF suppression effect between survivors and non-survivors, but not between inhalation and non-inhalation victims. The results suggest the presence of one or more factors in subeschar tissue fluid that inhibit both muscle and liver amino acid transport. The data also suggest that the inhibitory factors are most likely produced by the burned tissue. This suppression effect may be beneficial to burn victims in maintaining near-normal vascular osmolarity by way of an increased plasma amino acid level.
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Affiliation(s)
- Y W Tang
- Plastic and Reconstructive Surgery, Taichung Veterans General Hospital, Taiwan.
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Hwang TL, Yang JT, Lau YT. Arginine-nitric oxide pathway in plasma membrane of rat hepatocytes during early and late sepsis. Crit Care Med 1999; 27:137-41. [PMID: 9934907 DOI: 10.1097/00003246-199901000-00041] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To study the transported L-arginine in rat hepatocytes during different stages of sepsis. DESIGN A prospective, controlled study. SUBJECTS Thirty-six Sprague-Dawley male rats (250 to 300 g) were anesthetized and studied. INTERVENTIONS Early sepsis was produced 9 hrs after cecal ligation and puncture (CLP) and late sepsis developed 18 hrs after CLP. The control group underwent sham operation. Plasma membrane of rat hepatocytes was prepared by differential centrifugation. The [3H] L-arginine uptake of plasma membrane vesicles during sepsis was measured and inhibition studies employing omega-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine were performed. MEASUREMENTS AND MAIN RESULTS L-arginine transport was saturable, increased linearly with plasma membrane protein concentration, and increased with uptake time up to 5 mins. [3H] L-arginine uptake increased by 77% to 121% (p < .05) during early sepsis, with no significant changes during late sepsis. Comparing inhibitors of nitric oxide synthase, L-NAME was effective in inhibiting L-arginine transport while aminoguanidine was not. CONCLUSIONS L-arginine transport was enhanced in rat hepatocytes during the early stage of sepsis. The increased uptake of L-arginine could contribute to the increase production of nitric oxide by hepatocyte during sepsis.
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Affiliation(s)
- T L Hwang
- Department of Surgery and Physiology and Chang Gung Memorial Hospital, School of Medicine, Chang Gung University, Taipei, Taiwan
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Gahl MJ, Benevenga NJ, Crenshaw TD. Rates of lysine catabolism are inversely related to rates of protein synthesis when measured concurrently in adult female rats induced to grow at different rates. J Nutr 1998; 128:1503-11. [PMID: 9732311 DOI: 10.1093/jn/128.9.1503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To test the effect of changes in the rate of protein synthesis on amino acid oxidation, both were studied concurrently in individual 200-g female Sprague-Dawley rats. In a growth trial (Experiment 1), recombinant bovine somatotropin (rbST) was injected subcutaneously (0, 2 or 12 mg/d) over 6 d (n = 4 rats per rbST level). Weight gain increased with rbST level (P < 0.01); 1.96 +/- 0.8, 4.24 +/- 0.8 and 8.67 +/- 0.8 g/d, respectively. After treatment with rbST (0 or 12 mg/d) for 4 d (Experiment 2), rats were injected via a tail vein catheter with valine (400 mmol, 4.07 mBq L-[3,4(n)-3H]valine) at 0, 4, 10, 13 or 16 h after the daily rbST injection and killed 20 min later. This flooding dose was 5 to 6 times, not 10 times, the free pool as hoped. Protein synthesis in rbST-treated rats increased 46% in muscle (P < 0.001) and 36% in liver (P < 0.01). The ks was unaltered with time after rbST injection (0-16 h, P > 0.05). When 600 mmol valine (4.4 mBq L-[3,4(n)-3H]valine) was used in Experiment 3, specific activity (SA) of free valine was constant over 20 min and was 94 +/- 4% of that injected. Finally, in Experiment 4, protein synthesis and amino acid oxidation rates measured in the same rat revealed a 35% increase (P < 0.01) in protein synthesis in hind leg muscle and a 29% increase in liver (P < 0.05) from rbST-injected (12 mg/d) rats (n = 6). Lysine oxidation was estimated by continuous (12 h) infusion of L-[1-14C]lysine via the opposite tail vein catheter. Expired CO2 was collected over 20-min intervals and SA at plateau was estimated by fitting an exponential model. Lysine oxidation was reduced (P < 0.05) by 44% in rbST-treated rats. The idea that an increase in protein synthesis results in decreased amino acid oxidation remains tenable.
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Affiliation(s)
- M J Gahl
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
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Grøfte T, Jensen DS, Grønbaek H, Wolthers T, Jensen SA, Tygstrup N, Vilstrup H. Effects of growth hormone on steroid-induced increase in ability of urea synthesis and urea enzyme mRNA levels. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:E79-86. [PMID: 9688877 DOI: 10.1152/ajpendo.1998.275.1.e79] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Growth hormone (GH) reduces the catabolic side effects of steroid treatment due to its effects on tissue protein synthesis/degradation. Little attention is focused on hepatic amino acid degradation and urea synthesis. Five groups of rats were given 1) placebo, 2) prednisolone, 3) placebo, pair fed to the steroid group, 4) GH, and 5) prednisolone and GH. After 7 days, the in vivo capacity of urea N synthesis (CUNS) was determined by saturating alanine infusion, in parallel with measurements of liver mRNA levels of urea cycle enzymes, N contents of organs, N balance, and hormones. Prednisolone increased CUNS (micromol . min-1 . 100 g-1, mean +/- SE) from 9.1 +/- 1.0 (pair-fed controls) to 13.2 +/- 0.8 (P < 0.05), decreased basal blood alpha-amino N concentration from 4.2 +/- 0.5 to 3.1 +/- 0.3 mmol/l (P < 0.05), increased mRNA levels of the rate- and flux-limiting urea cycle enzymes by 20 and 65%, respectively (P < 0. 05), and decreased muscle N contents and N balance. In contrast, GH decreased CUNS from 6.1 +/- 0.9 (free-fed controls) to 4.2 +/- 0.5 (P < 0.05), decreased basal blood alpha-amino N concentration from 3. 8 +/- 0.3 to 3.2 +/- 0.2, decreased mRNA levels of the rate- and flux-limiting urea cycle enzymes to 60 and 40%, respectively (P < 0. 05), and increased organ N contents and N balance. Coadministration of GH abolished all steroid effects. We found that prednisolone increases the ability of amino N conversion into urea N and urea cycle gene expression. GH had the opposite effects and counteracted the N-wasting side effects of prednisolone.
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Affiliation(s)
- T Grøfte
- Department of Medicine V, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
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Balteskard L, Unneberg K, Mjaaland M, Jenssen TG, Revhaug A. Growth hormone and insulinlike growth factor 1 promote intestinal uptake and hepatic release of glutamine in sepsis. Ann Surg 1998; 228:131-9. [PMID: 9671077 PMCID: PMC1191438 DOI: 10.1097/00000658-199807000-00019] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To study the effects of growth hormone (GH) and insulinlike growth factor 1 (IGF-1) on whole body and gastrointestinal (GI), hepatic, femoral, and renal glutamine (GLN) uptake and release in septic piglets. SUMMARY BACKGROUND DATA The GI metabolism of GLN is impaired during sepsis, and this may contribute to a breakdown of the gut's mucosal barrier. GH treatment has produced increased GI GLN uptake in surgical stress. Little is known about the effects of GH and IGF-1 in sepsis. METHODS Twenty-four piglets were randomized to three groups of eight each: a GH group received a bolus of 16 IU of Genotropin; an IGF-1 group received a continuous infusion of 1.3 mg/hour of IGF-1; and a control group received saline. After surgical preparation, sepsis was induced with live Escherichia coli bacteria. Using isotope technique, whole body turnover and organ-specific absolute uptake and release were measured before and 4 hours after sepsis. RESULTS After sepsis, both GH and IGF-1 treatment increased GI GLN uptake compared with controls and induced hepatic release of GLN. GLN release from skeletal muscle was diminished in all groups after sepsis. Whole body GLN turnover was increased in the GH and IGF-1 groups compared with the controls, before and after sepsis. CONCLUSIONS GH and IGF-1 treatment induced increased GI net uptake of GLN. GH and IGF-1 treatment also promoted absolute and net release of GLN from the liver. This release might facilitate increased GI uptake despite reduced hindleg release in the early phase of sepsis.
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Affiliation(s)
- L Balteskard
- Department of Surgery, Tromsø University Hospital, Norway
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Easson AM, Bode BP, Fischer CP, Souba WW. Effects of endotoxin challenge on hepatic amino acid transport during cancer. J Surg Res 1998; 77:29-34. [PMID: 9698528 DOI: 10.1006/jsre.1998.5323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The hepatic uptake of amino acids is increased in both sepsis and cancer, and this response appears to be both global and essential in the catabolic host. Because immunocompromised cancer patients are susceptible to episodes of gram-negative sepsis, we examined the capacity of hepatocytes from normal and tumor-influenced livers to respond to the additional challenge of endotoxemia via increases in the Na+-dependent uptake of glutamine and zwitterionic amino acids by System N and System A, respectively. MATERIALS AND METHODS Fischer 344 rats were implanted with methylcholanthrene-induced fibrosarcomas. Control rats were sham-operated and pair-fed. Animal pairs (tumor burden = 8-32% carcass weight) were injected intraperitoneally with either Escherichia coli endotoxin (10 mg/kg) or PBS, and after 4 h, hepatocytes were isolated from the livers of the animals via collagenase perfusion and placed in primary culture. Three hours later, amino acid transport rates were measured using radiolabeled glutamine for System N and alpha-methylaminoisobutyric acid (MeAIB), a nonmetabolizable substrate specific for System A. RESULTS Cancer-independent of tumor size-and endotoxin each elicited similar 1.5- to 2-fold inductions of System N activity. When combined, their effects were additive rather than synergistic. In contrast, endotoxin induced an insignificant increase in System A activity, whereas cancer stimulated this carrier 2-fold in either the absence or the presence of endotoxin. CONCLUSIONS The primary glutamine and alanine carriers in hepatocytes are differentially influenced during catabolic states, and the tumor-influenced liver is competent to further increase glutamine uptake in response to additional catabolic insults.
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Affiliation(s)
- A M Easson
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, 02114, USA
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Turner ND, Knapp JR, Byers FM, Kopchick JJ. Expression of mutant bovine growth hormone genes in mice perturbs age-related nutrient utilization patterns. J Nutr 1998; 128:520-4. [PMID: 9482758 DOI: 10.1093/jn/128.3.520] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Three lines of transgenic mice expressing mutant bovine growth hormone (bGH) genes and displaying small (G119K), near normal (M11) or large (M4) phenotypes and nontransgenic control (NTC) mice were used to determine GH-associated, age-specific changes in empty body composition. The single amino acid substitution in G119K mice reduced the quantities (P < 0.001) and early rates (P < 0.05) of deposition for water, protein and ash but resulted in similar quantities of fat as the NTC mice. The change in relative quantities of empty body components indicated the G119K analogue altered nutrient partitioning, basal metabolism and (or) nutrient availability to effect the differential observed in body composition. The two amino acid substitutions in the bGH gene expressed by the M11 mice caused only a small change in phenotype, but age-related changes in the accretion of protein, fat and ash indicated these mice were not mature by 68 d of age. The bGH analogue produced by the M4 mice resulted in a doubling (P < 0.001) of body weight in comparison with the NTC mice, a result of the increasing (P < 0.001) rate of weight gain. Empty body component gain of the M4 mice also indicated they had not yet matured by 68 d of age. The G119K and M4 mutant forms of bGH altered rates and composition of growth, possibly through redirection of tissue nutrient utilization, modification of nutrient metabolism, and(or) nutrient availability.
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Affiliation(s)
- N D Turner
- Texas A&M University, Department of Animal Science and Faculty of Nutrition, College Station, TX 77843-2471, USA
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Shimoda N, Tashiro T, Yamamori H, Takagi K, Nakajima N, Ito I. Effects of growth hormone and insulin-like growth factor-1 on protein metabolism, gut morphology, and cell-mediated immunity in burned rats. Nutrition 1997; 13:540-6. [PMID: 9263235 DOI: 10.1016/s0899-9007(97)00033-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of recombinant human growth hormone (GH) and insulin-like growth factor-1 (IGF-1) were investigated in burned rats. Sprague-Dawley rats were fed exclusively by total parenteral nutrition and were subjected to 20% third-degree scald burns. The rats were then divided into the following three groups: (1) the GH group received GH at a dose of 1 IU.kg-1.d-1 for 2d (n = 10); (2) the IGF group received IGF-1 at a dose of 4 mg.kg-1.d-1 for 2d (n = 19); and (3) the control group received saline (n = 17). Cumulative nitrogen balance increased significantly in the GH (P < 0.01) and IGF (P < 0.01) groups as compared with the control group. There were no differences in nitrogen balance between the GH and IGF groups. Blood glucose was decreased in the IGF group (P < 0.01) and increased in the GH group (P < 0.05) as compared with the control group. The intestinal villus height and wall thickness of the GH and IGF groups were significantly greater than those of the control group. Delayed-type hypersensitivity was enhanced in both the GH and the IGF groups as compared with the control group (both P < 0.01). Furthermore, the increase in the IGF group was significantly greater than that in the GH group (P < 0.05). It was concluded that both GH and IGF-1 improve protein metabolism and immune responsiveness, as well as promote proliferation of the intestinal mucosa.
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Affiliation(s)
- N Shimoda
- First Department of Surgery, School of Medicine, Chiba University, Japan
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16
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Grøfte T, Wolthers T, Jensen SA, Møller N, Jørgensen JO, Tygstrup N, Orskov H, Vilstrup H. Effects of growth hormone and insulin-like growth factor-I singly and in combination on in vivo capacity of urea synthesis, gene expression of urea cycle enzymes, and organ nitrogen contents in rats. Hepatology 1997; 25:964-9. [PMID: 9096605 DOI: 10.1002/hep.510250429] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Improvement of nitrogen balance is desirable in patients with acute or chronic illness. Both growth hormone (GH) and insulin-like growth factor-I (IGF-I) are promising anabolic agents, and their combined administration has been shown to reverse catabolism more efficiently than each of the peptides alone. This is believed to be mediated primarily through increased peripheral protein synthesis, whereas little attention has focused on a possible participation of amino acid metabolism in the liver. Four groups of rats were given: 1) placebo; 2) GH (200 micrograms/d); 3) IGF-I (300 micrograms/d); and 4) both GH and IGF-I. After 3 days, the maximum capacity of urea-nitrogen synthesis was determined by saturating infusion of alanine (n = 8 in each group), together with measurements of liver messenger RNA (mRNA) levels for urea cycle enzymes (n = 5 in each group) and N-contents of muscles, heart, and kidney. Basal plasma alpha-amino acid concentrations were similar in all groups. The capacity of urea-N synthesis [mumol/(min x 100 g body weight)] was reduced in a stepwise manner (placebo: 8.25 +/- 1.2; GH treatment: 6.52 +/- 0.8; IGF-I treatment: 5.5 +/- 0.6; and GH/IGF-I: 4.22 +/- 1.6 [P < .001 by ANOVA]), each step being lower than the former. Serum IGF-I increased stepwise from placebo (699 +/- 40 to 1,579 +/- 96 micrograms/L in the combined GH/IGF-I group), and was correlated negatively with the capacity of urea-nitrogen synthesis (P < .01). mRNA levels for urea cycle enzymes in the liver decreased after GH and IGF-I treatment, and the effect was more pronounced after the combined treatment in which the rate-limiting enzyme, argininosuccinate synthetase, was halved. Nitrogen contents of organs increased after both GH and IGF-I treatment, and even more so after the combination treatment, reaching an increase of 30% (P < .05). Data suggest that GH and IGF-I singly and, even more so in combination, additively inhibit urea synthesis. This is supposed to favor protein buildup in organs. We speculate that this inhibitory effect on the capacity of urea synthesis is caused by a decreased translation rate of the urea cycle enzymes caused by GH and IGF-I's down-regulatory effect on urea cycle enzyme gene transcription. The findings may indicate a novel mechanism of the protein anabolic action of GH and IGF-I.
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Affiliation(s)
- T Grøfte
- Department of Medicine V (Hepatology and Gastroenterology), Aarhus Kommunehospital, Denmark
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17
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Caperna TJ, Gavelek D. Influences of somatotropin on Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPases of Porcine visceral tissues. Comp Biochem Physiol B Biochem Mol Biol 1996; 115:13-8. [PMID: 8896328 DOI: 10.1016/0305-0491(96)00082-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Two experiments were conducted to determine the overall influence of porcine somatotropin (pST) administration on the specific activity of visceral tissue ATPases. Pigs were fed a corn-soybean meal-skim milk-based diet approximately 85% of ad libitum, such that for each experiment, control and pST-treated pigs consumed similar amounts of feed. As observed for pigs chronically treated with pST, enhanced growth of visceral tissues was evident in pigs treated for 6 and 14 days (d) with pST. The specific activity of detergent-activated Na(+)-K(+)-ATPase (ouabain-sensitive adenosine triphosphatase activity) was determined in fresh tissue homogenates prepared from liver, heart, kidney and duodenum. Treatment with pST was associated with a 19% increase in Na(+)-K(+)-ATPase-specific activity in the liver; specific activity of Mg(2+)-ATPase was not influenced by pST. Whole liver Na(+)-K(+)-ATPase and Mg(2+)-ATPase activities were 35% and 25% greater, respectively, in somatotropin-treated pigs. The specific activities of Na(+)-K(+)-ATPase in heart, kidney and duodenum were similar for controls and pigs treated for 14 d with pST. The specific activities of high- and low-affinity Ca(2+)-ATPase in kidney medulla were 20 and 26% lower, respectively, in pigs treated for 14 d with pST compared with controls. In contrast, Ca(2+)-ATPases in other tissues, including kidney cortex, were not influenced by pST treatment. These data indicate that some of the observed increase in energy expenditure associated with pST treatment may be attributable to increased organ size as well as to enhanced hepatic Na+ and K+ flux. While Na(+)-K(+)-ATPase activity is specifically enhanced in the liver, pST does not appear to be a general Na(+)-K(+)-ATPase activator in all tissues and may be associated with depressed activity of Ca(2+)-ATPases in the kidney.
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Affiliation(s)
- T J Caperna
- USDA-ARS, LPSI, Growth Biology Laboratory, Beltsville, MD 20705, USA
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18
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Jeevanandam M, Ali MR, Holaday NJ, Petersen SR. Adjuvant recombinant human growth hormone normalizes plasma amino acids in parenterally fed trauma patients. JPEN J Parenter Enteral Nutr 1995; 19:137-44. [PMID: 7609279 DOI: 10.1177/0148607195019002137] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The addition of an anabolic stimulant during intensive nutrition therapy in trauma patients seems to be a reasonable adjuvant for minimizing muscle-mass erosion. The plasma free amino acid pattern is the mirror of the net amino acid metabolism, and we have measured the progressive changes resulting from recombinant human growth hormone therapy in trauma victims during nutritional repletion in the early catabolic flow phase of injury. METHODS In 20 severely injured (injury severity scale = 31 +/- 2), highly catabolic, and hypermetabolic adult multiple-trauma patients, we have measured the fasting (day 0) plasma amino acid levels (48 to 60 hours after injury before starting the nutrition therapy) and their progressive changes during 7 days of IV nutrition support (total parenteral nutrition, 1.1 x resting energy expenditure calories, 250 mg of nitrogen per kilogram per day) with or without adjuvant recombinant human growth hormone. Group H (n = 10) randomly received daily recombinant human growth hormone (0.15 mg of Somatropin per kilogram per day) and Group C (n = 10) received the vehicle of infusion. RESULTS Hypoaminoacidemia of trauma is normalized by infusion of recombinant human growth hormone, which indicates its anabolic nature, and this is confirmed in the cumulative nitrogen balance (-281 +/- 139 mg of nitrogen per kilogram per 7 days compared with -809 +/- 151 mg of nitrogen per kilogram per 7 days without recombinant human growth hormone; p < or = .005). This improved nitrogen retention is also reflected in the significantly low blood urea nitrogen levels in the recombinant human growth hormone group, which represents the efficient utilization of the infused amino acids for synthesis of proteins. Elevated plasma insulin-like growth factor-1 levels in Group H compared with those in Group C may also account for this altered amino acid metabolism. CONCLUSIONS Recombinant human growth hormone treatment in combination with conventional total parenteral nutrition in the immediate posttraumatic period improved nitrogen metabolism and normalized the plasma free amino acid levels.
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Affiliation(s)
- M Jeevanandam
- Trauma Center, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA
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Inoue Y, Copeland EM, Souba WW. Growth hormone enhances amino acid uptake by the human small intestine. Ann Surg 1994; 219:715-22; discussion 722-4. [PMID: 8203982 PMCID: PMC1243230 DOI: 10.1097/00000658-199406000-00016] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE The effects of growth hormone (GH) on the luminal transport of amino acids and glucose by the human small intestine were investigated. SUMMARY BACKGROUND DATA The anabolic effect of growth hormone administration is associated with nitrogen retention and an increase muscle strength, but the impact of growth hormone on nutrient uptake from the gut lumen has not been examined. METHODS Twelve healthy patients received a daily subcutaneous dose of low-dose GH (0.1 mg/kg), high-dose GH (0.2 mg/kg), or no treatment (controls) for 3 days before surgery. At operation, ileum (8 patients) or jejunum (4 patients) was resected, and brush border membrane vesicles (BBMVs) were prepared by differential centrifugation. Vesicle purity was confirmed by a 16-fold enrichment of marker enzymes. The carrier-mediated transport of glutamine (System B), leucine (System L), alanine (System B), arginine (System y+), MeAIB (methyl alpha-aminoisobutyric acid [System A]), and glucose (Na(+)-dependent glucose transporter) by BBMVs was measured by a rapid mixing/filtration technique. RESULTS Treatment with low-dose GH resulted in a statistically insignificant increase in amino acid transport rates in jejunal and ileal BBMVs. High-dose GH resulted in a generalized 20%-to 70%-stimulation of amino acid transport, whereas glucose transport was not affected. The effects of GH were similar in ileum and jejunum. Kinetic analysis of the transport of glutamine (the most abundant amino acid in the body and the principal gut fuel) and the essential amino acid leucine revealed that the increase in transport was caused by a 50% increase in carrier Vmax, consistent with an increase in the number of functional carriers in the brush border membrane. Pooled analysis of transport velocities demonstrated that total rates of amino acid uptake from the gut lumen were increased significantly by 35% in GH-treated patients. CONCLUSIONS The ability of GH to enhance amino acid uptake from the gut lumen provides energy and precursors for protein synthesis in the gut mucosa, as well as additional substrate for anabolism in other organs.
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Affiliation(s)
- Y Inoue
- Department of Surgery, University of Florida College of Medicine, Gainesville
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Takano K, Mouri N, Sakurai H, Muto S, Koshizuka K, Tada Y. Effect of growth hormone on wound healing in protein-malnourished rats treated with corticosteroids. J Pediatr Surg 1994; 29:790-3. [PMID: 8078023 DOI: 10.1016/0022-3468(94)90372-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study was designed to evaluate the efficacy of human growth hormone (GH) in improving the tensile strength of wounds weakened by chronic protein malnourishment and corticosteroid (CS) administration. Eighty-six female Sprague-Dawley rats, weighing 80 to 100 g, were divided into five groups. Group 1 (control) received 23.4% protein chow for 8 weeks before surgery. Groups 2, 3, 4, and 5 received nonprotein chow on alternate days for the same duration. Groups 3 and 5 received prednisolone (2 mg/kg/d intramuscularly) for 3 weeks preoperatively and for 5 days postoperatively. Groups 4 and 5 were given GH (somatotropin, 1 IU/d) for 5 days postoperatively. All the animals underwent a precise 4-cm midline celiotomy. Wound testing was performed on the sixth postoperative day, after removal of the sutures. The bursting strength (BS, mean +/- SD) for group 1 was 145 +/- 16 mm Hg. The BS for groups 4 (137 +/- 13 mm Hg) and 5 (134 +/- 7 mm Hg) were significantly stronger than those for groups 2 (115 +/- 15 mm Hg) and 3 (91 +/- 16 mm Hg). The authors conclude that postoperative systemic GH restored the wound BS in protein-malnourished animals treated with CS, to the level of the normally nourished controls.
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Affiliation(s)
- K Takano
- Second Department of Surgery, Yamanashi Medical University, Japan
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Inoue Y, Bode BP, Beck DJ, Li AP, Bland KI, Souba WW. Arginine transport in human liver. Characterization and effects of nitric oxide synthase inhibitors. Ann Surg 1993; 218:350-62; discussion 362-3. [PMID: 7690540 PMCID: PMC1242978 DOI: 10.1097/00000658-199309000-00014] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE Arginine transport was characterized and studied in human liver. SUMMARY BACKGROUND DATA Plasma arginine uptake may regulate hepatocyte intracellular availability and the subsequent biosynthesis of nitric oxide (NO), but little is known about arginine transport across the human hepatocyte plasma membrane. METHODS The authors characterized plasma membrane transport of 3[H]-L-arginine in hepatic plasma membrane vesicles (HPMVs) and in hepatocytes isolated and cultured from human liver biopsy specimens. They also studied the effects of the NO synthase inhibitors omega-nitro-L-arginine methyl ester (L-NAME) and N-methyl-arginine (NMA) on arginine transport in HPMVs and in cultured cells. RESULTS Arginine transport was saturable, Na(+)-independent, temperature and pH sensitive, and was inhibited by the naturally occurring amino acids lysine, homoarginine, and ornithine (System y+ substrates). Arginine transport by both vesicles and cultured hepatocytes was significantly attenuated by NO synthase inhibitors, suggesting that the arginine transporter and the NO synthase enzyme may share a structurally similar arginine binding site. Dixon plot analysis showed the blockade to occur by competitive, rather than noncompetitive, inhibition. In vivo treatment of rats with lipopolysaccharide (LPS) resulted in a twofold stimulation of saturable arginine transport in the liver. This LPS-induced hepatic arginine transport activity was also inhibited by L-NAME. These data indicate that arginine transport by human hepatocytes is mediated primarily by the Na(+)-independent transport System y+. CONCLUSIONS Besides inhibition of the NO synthase enzyme, the ability of arginine derivatives to block NO production may also be due to their ability to competitively inhibit arginine transport across the hepatocyte plasma membrane. The use of selective arginine derivatives that compete with arginine at the plasma membrane level may be a metabolic strategy that can be used to modulate the septic response.
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Affiliation(s)
- Y Inoue
- Department of Surgery, University of Florida College of Medicine, Gainesville
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Souba WW, Pacitti AJ. How amino acids get into cells: mechanisms, models, menus, and mediators. JPEN J Parenter Enteral Nutr 1992; 16:569-78. [PMID: 1494216 DOI: 10.1177/0148607192016006569] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The bloodstream provides a readily available pool of amino acids, which can be taken up by all cells of the body to support the myriad of biochemical reactions that are essential for life. The transport of amino acids into the cytoplasm occurs via functionally and biochemically distinct amino acid transport systems that have been defined on the basis of their amino acid selectivities and physico-chemical properties. Each system presumably relates to a discrete putative membrane-bound transporter protein that resides within the cell membrane and functions to translocate the amino acid from the extracellular environment into the cytoplasm. Many of these transporters require sodium for maximal activity. The sodium-dependent model presented is consistent with "preferred random" kinetics, with sodium binding preferentially before the amino acid. The transporter acts as an enzyme that catalyzes the movement of its bound amino acid (and sodium) into the cell. In this review, the authors provide a conceptual view of the mechanism of carrier-mediated amino acid transport as well as an overview of the various models that can be used in the laboratory to study this process. In addition, the known agencies that accomplish transport and their regulation by nutrition, hormones, and other mediators of critical illness are discussed.
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Affiliation(s)
- W W Souba
- Department of Surgery, University of Florida College of Medicine, Gainesville
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