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Tissue imbalance of amino acids in starved rats: Efficiency of ornithine α-ketoglutarate (OKG) versus glutamine (GLN) during refeeding
OF AMINO ACIDSIN SURVEDRATS: EFFICIENCY OF OR~I~NE (I-0.75 TIS~~BIMBALANCE
(OKG) vmsus
GLUTAMINE (GLN)MIRING KEFEEDING. F. Ziegler, C. Coudrey-Lucas, F. Bonnet, A. Jerdel, E. Lssnier, J. Agneray, O.G. Kkindjien, L. Cynober Lab. Biochem. CNRSUA622 end Dept of Physiology, University Paris KI - Chateney-Melabry- FRANCE Recent interesting studies performed in various catabolic states have pointed out the action of OKGend GLN in correcting protein metabolism disorders. The aim of this study wes to compare the efficiency of these 2 molecules in en experimental model which provides a well characterized disorder of amino acid patterns. Hale Wistar rets (187 f 11 K) were starved for 3 days and then refed for 7 days with oral nutrition (2.25 KN/kg/day) being randomlyassigned (n = 5 in each group) to receive e supplement (0.19 gN/kg/day) of either OKG, GLN or casein (control proup). Amino acids concentrations were measured in plasma, muscle, liver and smell intestine, before end after starvation and on day 7 of refeeding. Stervetion induced a strong decrease in smell intestine end liver weight (45 %, p < O.OOl), in small intestine protein content (41 %, p < 0.001) end in most essential and non essential amino ecids in all tissues with the notable exception of muscle leucine end of liver glutamate end glut&nine which increased significently by 37 %, (p < 0.01) 12 %, (p < 0.05) and 14 % (p < 0.05) respectively. In the control group, abnormalamino acid patterns in liver end intestine were partially corrected but not in muscle. GLNonly normalized its win pool in muscle. OKGnormalized 7 (including proline end branched chain amino acids) of 11 abnormal amino acid concentrations in liver end 5 (including glutamate and alanine) of 7 in intestine. In conclusion, oral dietary supplementation with OKGis more effective than with glutamine in correcting abnormalamino acid patterns in the intestine end liver of starved rats.
0.76 BRADYKININREDUCESGLUCAGON-INDUCED LEUCINE OXIDATION. W.H&rtl, W.Jauch, F.Jahoor, R.R.Wo1f-e. DepartmentUniversity,. Bunich, kest. Germany; Shriners
T.U.Cohnert, K.of Surgery, -Klinikum Grosshadern, LB Burns Institute, Galveston, Texas, USA.
-In surgical stress, leucine .IS both released from proteinand-oxidized at an increased.rate. Glucagon has-been-proposed.as a -mediator of these changes. .On the bradykinin (BK) may activate protein synthesis in-vitro. We therefore other hand, “tested the hypothesis that glucagon-stimulates leucine oxidation and-release and Five healthy volunteers were infused that BK counteracts the effects of glucagon. twice with glucagon. After a baseline peri_od (glucagon infusion rate 0.5 ng/kg was raised to 3.0 ng/kg min in each Study. On one infusion rate min), glucagon a low-dose BK infusion (30 ng/kg min) was given in addition to the high occasion, Endogenoas glucagon and-insulin secretion was suppressed by glucagon infusion. somatostatin infusion throughout the entire study and insulin was replaced at a basal rate. I-‘SC-leucine was used to.determine leucine kinetics. Results: Hyperglucagonemia significantly increased leucine oxidation (0.78 f 0.09 .mrnin vs basal 0.45 + 0.10, pt0.05), but did not accelerate leudine flux. BK significantly reduced the glucagon-induced rise in leucine oxidation (0.63 f 0.06 umol/kg inin vs glucagon’ alone 0.78 f 0.09, ~(0.05). Eonclusion: The glucagon-induced rise in leucine oxidation indicates that glucagon (as estimated from non-oxidative leucine flux) may decrease protein synthesis and/or may selectively stimulate branched-chain 2-oxo-acid dehydrogenase. BK atin leucine oxidation. This effect may be due tenuated the glucagon-mediated rise to the stimulatien of protein synthesis, since-prostaglandins, the second messengers of BK have been claimed to activate ribosomal protein -formation.
48
(OKG) vmsus
GLUTAMINE (GLN)MIRING KEFEEDING. F. Ziegler, C. Coudrey-Lucas, F. Bonnet, A. Jerdel, E. Lssnier, J. Agneray, O.G. Kkindjien, L. Cynober Lab. Biochem. CNRSUA622 end Dept of Physiology, University Paris KI - Chateney-Melabry- FRANCE Recent interesting studies performed in various catabolic states have pointed out the action of OKGend GLN in correcting protein metabolism disorders. The aim of this study wes to compare the efficiency of these 2 molecules in en experimental model which provides a well characterized disorder of amino acid patterns. Hale Wistar rets (187 f 11 K) were starved for 3 days and then refed for 7 days with oral nutrition (2.25 KN/kg/day) being randomlyassigned (n = 5 in each group) to receive e supplement (0.19 gN/kg/day) of either OKG, GLN or casein (control proup). Amino acids concentrations were measured in plasma, muscle, liver and smell intestine, before end after starvation and on day 7 of refeeding. Stervetion induced a strong decrease in smell intestine end liver weight (45 %, p < O.OOl), in small intestine protein content (41 %, p < 0.001) end in most essential and non essential amino ecids in all tissues with the notable exception of muscle leucine end of liver glutamate end glut&nine which increased significently by 37 %, (p < 0.01) 12 %, (p < 0.05) and 14 % (p < 0.05) respectively. In the control group, abnormalamino acid patterns in liver end intestine were partially corrected but not in muscle. GLNonly normalized its win pool in muscle. OKGnormalized 7 (including proline end branched chain amino acids) of 11 abnormal amino acid concentrations in liver end 5 (including glutamate and alanine) of 7 in intestine. In conclusion, oral dietary supplementation with OKGis more effective than with glutamine in correcting abnormalamino acid patterns in the intestine end liver of starved rats.
0.76 BRADYKININREDUCESGLUCAGON-INDUCED LEUCINE OXIDATION. W.H&rtl, W.Jauch, F.Jahoor, R.R.Wo1f-e. DepartmentUniversity,. Bunich, kest. Germany; Shriners
T.U.Cohnert, K.of Surgery, -Klinikum Grosshadern, LB Burns Institute, Galveston, Texas, USA.
-In surgical stress, leucine .IS both released from proteinand-oxidized at an increased.rate. Glucagon has-been-proposed.as a -mediator of these changes. .On the bradykinin (BK) may activate protein synthesis in-vitro. We therefore other hand, “tested the hypothesis that glucagon-stimulates leucine oxidation and-release and Five healthy volunteers were infused that BK counteracts the effects of glucagon. twice with glucagon. After a baseline peri_od (glucagon infusion rate 0.5 ng/kg was raised to 3.0 ng/kg min in each Study. On one infusion rate min), glucagon a low-dose BK infusion (30 ng/kg min) was given in addition to the high occasion, Endogenoas glucagon and-insulin secretion was suppressed by glucagon infusion. somatostatin infusion throughout the entire study and insulin was replaced at a basal rate. I-‘SC-leucine was used to.determine leucine kinetics. Results: Hyperglucagonemia significantly increased leucine oxidation (0.78 f 0.09 .mrnin vs basal 0.45 + 0.10, pt0.05), but did not accelerate leudine flux. BK significantly reduced the glucagon-induced rise in leucine oxidation (0.63 f 0.06 umol/kg inin vs glucagon’ alone 0.78 f 0.09, ~(0.05). Eonclusion: The glucagon-induced rise in leucine oxidation indicates that glucagon (as estimated from non-oxidative leucine flux) may decrease protein synthesis and/or may selectively stimulate branched-chain 2-oxo-acid dehydrogenase. BK atin leucine oxidation. This effect may be due tenuated the glucagon-mediated rise to the stimulatien of protein synthesis, since-prostaglandins, the second messengers of BK have been claimed to activate ribosomal protein -formation.
48