P.47 A COMPARISON OF THE EFFECTS OF CONTINUOUS AND CYCLIC NOCTURNAL TOTAL PARENTERAL NUTRITION ON PLASMA AMINO ACID CONCENTRATIONS AND URINARY AMINO ACID ELIMINATION

E. Lerebours, B. Hecketsweiler Ph. Denis, R. Colin - Groupe de Physiopathologie Digestive et Nutritionnelle, 76031 ROUEN Cedex FRANCE.

Cyclic nocturnal total parenteral nutrition (N.TPN) is an increasingly used method. Nevertheless, the metabolic implications of this technique have not been extensively investigated. The aim of this study was to compare the effects of N.TPN and continuous TPN (C.TPN) on plasma amino-acid (AA) concentrations and urinary AA elimination. Twelve patients with gastro-intestinal disease were investigated during 2 consecutive periods of 7 days with N.TPN (infusion from 17hOO to 09hOO) and C.TPN (infusion over 24h) in a random order. Over the two periods eneigy supply 59 Kcal/Kg/d (48-69) and ni- trogen intake, provided as a mixture of Totamine and Vamine (0.30 g/kg/d (0.25-0.36)), were the same. During the last day of each period we have performed at 08h30 and 16h30 a determination of plasma AA levels using Beckman 119 CL AA Analyzer. Last two days of each period was determined the 24 h urinary AA elimination. During C.TPN, total plasma q concentrations were not different at 08h30 (3703 nmol/l+ 270) and 16h3$ (3598 umol/l- 474). During N.TP$, total plasma AA.were higher at 08h30 (4190 umol/l- 510) than at 16h30 (2853 pmol/l- 224) (p < 0.05), with a significant difference for all AA but five (cysteine, tyrosine, citrulline, glutamine, taurine). In comparison with mean C.TPN values (mean of 08h30 and 16h30), total plasma AA during N.TPN were significantly higher at 08h30 (p < 0.05) and lower at 16h30 (p < 0.01). During N.TPN, plasma AA concentrations at 08h30 and AA changes between 08h30 and 16h30 were significantly correlated with AA intake. During N.TPN, for 1 umol of infusion per minute the most important rise in the AA concentrations concerns ornithine, alanine, proline, valine, and the lowest rise : cysteine, aspartate. Total urinary AA elimination was not different during C.TPN and N.TPN. These results demonstrate that, by comparison with the stability observed during C.TPN, N.TPN induces a more heterogeneous profile of plasma AA with particular regard to the unchanged levels of cysteine, tyrosine and glutamine during the infusion period.

P.48 EVBLUATION OF A NEW MODEL FOR METABOLIC STUDIES OF THE PERIPHERAL TISSUES DURING EXER- CISE WITH THE SUBJECT IN THE BED-RIDDEN POSITION F. Lundgren, K. Bennegard, A-C.Bylund- Fellenius, A. Elander, J. Holm, K. Lundholm & T. Schersten. Surgical Metabolic Research Laboratory, University of Gothenburg, Sahlgrenska Hospital, Gothenburg, Sweden.

Metabolic studies of the peripheral tissues are often performed with the subject exer- cising on a bicycle-ergometer while blood samples are drawn from the cathertized brac- hial artery and femoral vein. In diseased, bed-ridden or old patients this is not pos- sible. We have therefore evaulated a model for metabolic studies of peripheral tissues with the subject in the bed-ridden position.

Methods: Seven male subjects performed a submaximal and maximal exercise on a foot- ergometer in the bed-ridden position. Their VO2 and RQ were analysed with a ventilated

hood technique. Calf blood flow was measured with an ECG-triggered semicontinous ple- tysmograph at rest and immediately after exercise. The radial artery and popliteal vein were catheterised and blood samples drawn at rest, during the end of the exercise pe- riods and during the recovery phase. Blood gases, glycose, FFA, lactate, pyruvate and keton bodies were analyzed.

Results: When subjects worked approximately 30 and 50% of the V02max their oxygen con- sumption increased from 145+ 6 to 254 + 21 and 304 + 22 Amol/kg x min. Oxygen consup- tion of the calf increased From 9.1 + i.5 to 112.2 7 19.9 and 122.8 + 16.4 pmol/lOO ml x min.Calf blood flow increased from-j.7 + 1.0 to lg.4 + 1.7 and 21.6 + 1.8 ml/100 ml x min at rest and during the two exercise-periods respectively. RQ decreased from 0.88 + 0.02 to 0.69 + 0.02 and 0.82 + 0.03; glucose flux increased from 0.71 + 0.44 to 10.8 7 2.2 and 15.9 ; 4; FFA flux increased from 0.16 + 0.12 to 0.59 + 0.52 and 3.26 2 0.69 %nol/lOO ml x mzn. Venous lactate increased from i.03 + 0.11 to 3.06 + 0.50 and 3.04 2 0.47 mmol/l. 0 extraction increased from 0.36 + 0.05 to 0.59 + 0.07 arid 0.59 + 0.06 measured at re$t and during exercise with a wofk-load of 863 i 71 and 1465 + 310 Joule and an effect of 4.94 + 0.32 and 5.852 0.48 Watt.

Conclusions: This model seems to be ideally suitable for metabolic studies on bed-ridden subjects.

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