P57 EFFECTS OF LOW AND HIGH ENERGY SUPPLY AND DIFFERENT CARBOHYDRATE/FAT RA- TIOS DURING TOTAL PARENTERAL NUTRITION IN THE RAT. A.Wennberg, F.Martins, L.Lindmark and S.Meurling. Dept. of Exp.Nutr., R & D, KabiVitrum AB, Stock- holm & Dept. of Ped.Surg., Academic Hospital, Uppsala, Sweden.

Experiments were performed to evaluate the nutritional effects of in- creased energy supply and variation in the ratio between carbohydrate and fat. Total parenteral nutrition (TPN) with a complete amino acid solution was given via a permanent jugular vein catheter to growing rats for 10 days continuously. The nitrogen supply was 0.99 N/kg/day and non-protein energy 240 (low) and 320 (high) kcal/kg/day. Four different energy-ratios of alucose and fat fG/F) were tested: 100/O, 15.7. 2.33 and 0.67. The fat was-given as Intralipid'20%. The results regarding growth, N-balance (day 4-10) and utilization (NNU) and serum lipids during the experiment are gi- ven in the table below. ENERGY G/F GROWTH N-BALANCE NNU S-TG S-CHOL S-PL S-FFA Number kcal ratio 240 100/o 4%4

mg/day % mnol/l nsnol/l mmol/l umol/l of rats 104 73.6 1.7 1.3 1.5 160 7

15.7 4.0 100 2.33 7.4 93 0.67 -3.5 52

320 100/O 16.2 133 15.7 13.7 128 2.33 20.2 141 0.67 16.5 136

All rats tolerated the infusions

71.4 1.2 1.4 1.6 250 8

71.9 2.0 2.0 2.8 770 52.1 2.0 3.2 4:l 930 ; 86.5 1.8 1.5 1.8 270 7 87.9 1.8 1.5 1.6 180 8 90.5 2.0 2.5 87.1 3.3 4.4

::: 8 7

1;:: 9

well and had normal blood status after the test. EFA (18:2, 18:3 and 20:4) increased in subcutaneous and epididymal fat when more fat was included in the TPN reoimen, but no further increase was seen between the ratios 2.33 and 0.67. The increased incorporation of EFA was more pronounced at the high energy level. Water and protein con- tent in muscle and liver was similar in all groups. Conclusion: This study reveals the importance of selecting the optimal balance of energy substra- tes als well as total energy supply. TPN with a glucose/fat ratio of 2.3 (70% glucose/30% fat) seems to give maximal growth and N-utilization.

P58THE INFLUENCE OF ORAL AND PARENTERAL FAT ON PROTEIN METABOLISM IN RAT AND MAN P. Radermacher, T. Kaufmann, L. Herbertz, H. Reinauer. Biochemical Department, Diabetesforschungsinstitut, DUsseldorf, FRG

The effect of triglyceride application on protein metabolism, especially in skeletal muscle-, was investigated in a‘long term oral study in rats and a short term infusion study with metabolically healthy volun- teers. In the long term study rats were fed with olive oil (4 ml/d) for 3 days. The control group fasted throughout the whole experimental period. Urine was collected daily for 3-methylhistidine (3-MH) and total nitrogen (total-N) determination, blood samples were taken for amino acid (AA) ana- lysis. While in the fed group the 3-MH excretion did not change, it continously rose in the fasting qroup (3,l resp. up to 5,l l.rmol/24 h). The total-N excretion was not altered in'the fasting rats, while it decreased in the fed group due to the missing supply with AA (142 resp. down to 74 mg N/24 h). The concentrations of GLN, ALA, VAL, ILE, LEA were higher in the fasting group than in the fed group. In the short term study for 3 h the test persons were infused with lioid emulsions consistina of lona or medium chained triglycerides (120 mg/kg BW x h): group A LCT; group B MCT/LCT; orouo C MCT/LCT + isocaloric alucose: arouo D Icontrol) alvcerol. The total experimental period was 8 h. Urine was"coliected for AA an> total-N deter- mination, blood samples were taken each hour for AA analysis. While there were no differences in serum AA concentrations, the excretions of ALA, GLU + GLN, 3-MH were lower in the groups A, B and C than in group D (l,l, 3,2, 1,3 reps. 1,5, 4,6, 1,6 pmol/kg BW x 8 h). Total-N excretion was also lower in the fat groups (48 resp.59 mg N/kg BW x 8 h). There were no differences between the two lipid infusion regimens, nor with added glucose. From the present data we conclude that oral or parenteral fat has a nitrogen sparing effect, which may be due to the released FFA and/or the ketone bodies.

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