surviving animals were sacrificed and the mesenteric lymph nodes (MLN), liver (L) and spleen (S) excised under sterile conditions for aerobic cultures Results: BT in burned animals (groups l-5) was similar in MLN (20/35), L (16/36) and S (12/30). Control group showed no BT. SBD with comparison with no antibiotic groups (2 and 4) (4/12 vs 1 l/12, resp. p < 0.05), as well as in a lesser mortality rate (O/12 vs 5/17, resp. p < 0.05). As far as the nutritional therapy is concerned:

TPN TEN SAL

..-.. 7/l 1 8/l 1

10/12 7/l 3 216’ l/6’

I’ p < 0.05 resp. TPN and TEN)

with no difference in mortality rate. Conclusions: 1) SBD with neomycine reduces BT and mortality after burn injury. 2) Early postinjury nutritional therapy with TPN or TEN with polymeric diet promotes more BT than a normal standard rat chow.

P.37 Changes in protein metabolism in a zymo- san induced rat model of sepsis

O.E. Rooyackers, A.J.M. Wagenmakers, P.B. Soeters# and W. H. M. Saris Department of Human Biology and # General Surgery, Uni- versity of Limburg, Maastricht, The Netherlands

Characteristic changes in protein metabolism are seen during sepsis and critical illness. These among others involve a fall in muscle protein synthesis, a reduction of muscle glutamine (Gln) concentration and an acceleration of liver protein synthesis. lntraperitoneal (Lp.) injection of zymosan in rats has previously been described to lead to long term illness and protein catabolism. Here we investigate whether this model is suitable to study the metabolic response to sepsis both during acute and long term illness. Male Lewis rats (2200 g) were i.p. injected with either zymosan (50 mg suspended in 2 ml of paraffin per 100 g bodyweight) or paraffin. Because zymosan treatment significantly reduced food intake, control animals were pair-fed. Also an ad libitum fed control group was included. Protein synthesis rates were measured by the flooding dose technique using i.p. injected [3H]phenylalanine. Gln was measured by HPLC.

22 (n = 8) PF2 (n = 8) 26 (n = 6) food intake (g/day) 0.5f0.4# 17.1 f1.6# muscle ks (%/day) 5.1?1.0# 5.6+1.5# 6.9fl .O muscle weight (mg) 851+135#’ 1037k143# 799+115#’ muscle Gin (pmol/g ww) l.O+O.Z#’ 2.2+0.3 1.6?0.4# liver ks (%/day) 114*20#’ 77k16 82+12 liver weight (g) 7.2+0.7#’ 5.5+0.4# 9.3f1.5’

PFB (n = 6) Con (n = 8) food intake (g/day) 21.1+1.3 muscle ks (%/day) 6.5k1.5 8.2+1.3 muscle weight (mg) 1017~172# 1310+239 muscle Gln (qmol/g ww) 2.3kO.3 2.5+0.3 liver ks (%/day) 67?18 77*10 liver weight (g) 7.3+0.6# 9.1 io.7

Mean + SD. ks = fractional protein synthesis rate; Z = rymosa”; PF = pair fed; 2,6 are days after ~eatnwnt; Con = ad libitum fed control. ‘significant/y different from PF; f significantly different from Con, Student t-test, p c 0.05

The zymosan model shows the characteristic metabolic adap- tations to sepsis. The model seems suitable to study both acute and long term illness and could be useful when testing therapeutic interventions.

P.38 Decreases in cytochrome C oxidase activi- ties in muscle of a zymosan induced rat model of sepsis A.J.M. Wagenmakers, O.E. Rooyackers and J.M.G. Senden Department of Human Biology, University of Limburg. Maa- stricht, The Netherlands

Muscle weakness and a reduced exercise tolerance are observed in patients for month8 after recovery from critical illness. lntraperitoneal (i.p.) injection of zymosan in rats has been used as a model of critical illness and sepsis (Goris et al., Arch. Surg. 120: 897,1986). Here we measure in this rate model activities of cytochrome C oxidase (a mitochondrial respiratory chain enzyme) to investigate whether a reduction in the activity of mitochondrial enzymes plays a role in the weakness. Muscle weights are also measured to quantify the loss of muscle mass. Male Lewis rats (+200 g) were injected i.p. with either zymosan (50 mg suspended in 2 ml of paraffin per 100 g body weight) or paraffin only. Comparisons are made with fed and pair-fed control animals, becausezymosan treatment significantly reduced food intake.

Cytochrome C oxidase Gastrocnemicus (g)

~=n~l (fed) 22 PF2 n=8 n=8

172+29 50+26’,# 114*54# 1.31 +0.24 0.85*0.14,# 1.04&0.14#

Cytochrome C oxidase Gastrocnemicus (g)

26 PFB n=6 fl=B

75+38-# 125+22# O.EOi_O.lZ’~# 1.02+0.17#

Table: Cytochrome C oxidase activities (prnolfmin Jgram wet weight) and the weight of the m. gastrocnemicus are given as means + SD. Cytochrome C oxidase activities were measured as described by Gohil et al. Clin. Physiol. 1: 195 207, 1981. Z = zymosan; PF = pair-fed; 2 and 6 denote days after treatment. + Significantly different from pair-fed at p < 0.05; # Significantly different from fed control at p < 0.05, Student t-test. Zymosan treatment resulted in a substantial fall in muscle mass and cytochrome C oxidase activity. These data suggest that a reduction in muscle mass and loss of mitochondrial enzymes both contribute to the weakness and reduced exercise tolerance observed after recovery from critical illness.

P.39 Increased branched-chain 2-0~0 acid dehydrogenase activities in muscle in a zymo- san induced rat model of sepsis A.J.M. Wagenmakers, O.E. Rooyackers, P.B. Soeters# and W. H. M. Saris Departments of Human Biology and # Surgery, University of Limburg, Maastricht, The Netherlands

Previously it has been suggested that the oxidation of branched-chain amino acids (BCAA) is enhanced in skeletal muscle in patients with sepsis and trauma. lntraperitoneal (i.p.) injection of zymosan in rats has been used as a model of sepsis. Here we measure the activity of the branched- chain 2-0~0 acid dehydrogenase complex (BC-complex), the regulatory enzyme in the oxidative pathway of the BCAA in muscle and also plasma and muscle concentrations of BCAA (by HPLC). Male Lewis rats (_t200 g) were injected i.p. with either zymosan (50 mg suspended in 2 ml of paraffin per 100 g body weight) or paraffin only. Control animals were pair-fed because zymosan treatment significantly reduced food intake.

22 PF2 Z6 PF8

active BC-complex total BC-complex % active plasma z [BCAA] muscle 2 [ECAAI

(n = 8) (n&E, 1 .l +0.4 0.6kO.3 ?.,,“!I.,* (;.;:b.l

14.9+7.4’ 24.8f9.7 26.7+10.0 20.7+3.2 9.2 f 5.0’ 2.9f1.5 5.0+2.3’ 1.9*0.7

369+73 390+78 351 f 67 432?89 460+121 355+55

Table: Activities of the BC-complex (nmol/min/g wet weight) and the sum concentration (Z) of BCAA (rmol/l or pmol/g wet weight) are given as means + SD. Both the active (=dephosphorylated) and total amount of B&complex were measured as described before (Wagenmakers et al. Am. J. Physiol. 260: E883, 1991). Z = zymosan; PF = pair-fed; 2

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