P.104 Captopril reduces TNFα induced IL-1β synthesis in human peripheral blood monocytes, in vitro

GH, particularly on skeletal muscle, has been recently proposed as nutritional index. The study aimed to evaluate the nutritional significance of IGF-1 in patients with COPD by comparing IGF-1 with the traditional anthropometric and visceral parameters. Forty hospitalised patients with clinically stable COPD were studied. BPCO was diagnosed according to the American Thoracic Society. Nutritional assessment included: body mass index (BMI), midarm muscle circumference (MAMC), creatinine-height index (CHI), triceps skin fold (TSF), visceral proteins (serum albumin, transferrin, retinol-binding-protein and transthyretin), and hand-grip dinamometry (HG). Plasma IGF-1 was analysed by IRMA (DSL, Webster, USA) after acid-etanol extraction from its binding proteins. Reference IGF-1 values were derived from a normal population (135 healthy subjects, matched for sex and age with BPCO patients). Pulmonary function tests and maximal inspiratory (MIP) and expiratory pressure (MEP) were also evaluated. Malnutrition, as defined by BMI < 20, was found in 5/40 (12.5%) patients. Three other patients (7.5%), however, showed muscle mass depletion (MAMC < 5th percentile) in spite of a normal BMI. A slight decrease of one or more serum proteins was found in 5/40 patients (12.5%). IGF-1 correlated with MAMC% (P< 0.001), and to a lesser extent with BMI (P< 0.05), but not with serum albumin or other visceral proteins. MIP% correlated with IGF-1 (r= 0.50; P< 0.01) and HG% (r= 0.55, P< 0.01). In conclusion, IGF-1 appears to be related to muscle mass depletion in patients with COPD. Both IGF-1 and HG, indexes of skeletal muscle mass and skeletal muscle function respectively, are related to respiratory muscle function, confirming that malnutrition negatively influences pulmonary function.

P.103 Inhibition of cNOS, but not iNOS, causes renal insufficiency in endotoxemic rats M. M. Hallemeesch, D. C. R Cobben, N. E. R Deutz and R B. Soeters Department of Surgery, Maastricht University, The Netherlands. To study the role of nitric oxide and the individual iNOS and cNOS pathways in the pathogenesis of renal insufficiency during endotoxemia, we blocked these pathways by the administration of relatively cNOS (NW-nitro-L-arginine-methylester; L-NAME) or iNOS (smethylisothiourea; SMT) selective inhibitors. We measured renal function in endotoxemic (2 mg/kg at 0 and 12 h) rats that obtained the NOS inhibitor L-NAME (0, 25 or 50 mg/kg) or SMT (50mg/kg). All rats received fluid support at 0 and 12 h (saline, 10ml/100g s.c.). At t = 20 h, urine production and renal urea flux were measured as indicators of kidney function. Renal urea flux was calculated as the product of blood flow and AV difference. Results: Urine output was decreased dose dependently by L-NAME but not by SMT (LPS: 1.6 _ 0.1 ; L-NAME (25) 1.3 + 0.1 ; L-NAME (50) 1.0 _+0.2; SMT: 1.5 _+0.1 ml/100g/h. Renal blood flow was decreased by both L-NAME doses, but not by SMT administration (LPS: 1.6 -+0.2; LNAME (25) 0.7 +_ 0.2; L-NAME (50) 0.6 _+ 0.2; SMT 2.2 _+ 0.4 ml/100g/min). Plasma urea levels increased markedly in high dose LNAME rats, possibly due to decreased renal urea clearance. SMT had no effect on urea levels or renal urea flux.

Arterial urea Renal urea flux

P.102 Interferon gamma and interleukin 6 responses to peritoneal inflammation following parenteral and enteral nutrition S. Kobayashi, R. Fukushima and K. Okinaga Department of Surgery II, Teikyo University School of Medicine, Tokyo, Japan.

TPN TEN

1170 + 663 468 _+258

195 -+92 64 -+20

529 _+151 398 -+ 58

TPN TEN

Liver

8+4* 386_+40* 967+_202 602_+123

Interleukin 6 (mg/g)

MLN

Serum

Liver

67_+131 127_+26

ND ND

136-+18" ND 38-+3 ND

8.9-+0.6 -0.7 -+0.3

13.2-+1.1 0.2 -+0.3

7.4-+0.4 -1.5 + 0.9

Congestive heart failure is often complicated by catabolic processes, partly mediated by increased activity of pro-inflammatory cytokines like interleukin(IL)-113 and tumour necrosis factor (TNF)-(z. IL-I~, mainly produced in monocytes, is synthesised as a propeptide that is cleaved by the protease intedeukin converting enzyme in order to gain biological activity. The aims of this study were to evaluate whether the angiotensin converting enzyme inhibitor captopril 1) reduces monocyte production of IL-113 in vitro and 2) impairs the proteolysis of pro IL-1 ~. Methods: Blood was collected from healthy volunteers and monocytes were isolated by gradient technique. After two hours preincubation with captopril (0, 100,500 and 1000 pM) the cells (250 000 cells/ml) were stimulated for 24 h with either TNFc~ (10 ng/ml) or lipopolysaccharide (LPS 1 ng/ml). Cell and supernatants were separated and IL-I~ and prolL-11~ were analysed in both fractions by ELISA. Results: In five separate experiments, captopril gave a dose dependent reduction of TNFc~ induced IL-lJ3 synthesis in the intraceltular fraction. The reductions at the highest captopril concentration (1000 IJM) were 50-82%, mean 76%. Corresponding reductions in the TNF(z induced prolL-l~ synthesis were observed, ranging between 58-99%, mean 79%. The IL-1!3 and prolL-11~ concentrations in the supematants were low and was not affected by captopril. LPS induced IL-113 synthesis was not affected by captopril. Conclusion: Captopril reduced TNFc~ induced IL-lJ3 synthesis in monocytes in vitro. The effect seemed to be proximal to prolL-l~ proteolysis, since the synthesis of prolL-113 also was reduced by captopril. These results support the hypothesis that captopril has immunomodulating properties which might contribute to the beneficial effects of the drug in congestive heart failure.

Cytokine responses:

Serum

6.1 -+0.5 -0.7 -+0.4

P.104 Captopril reduces TNF~ induced IL-I~ synthesis in human peripheral blood monocytes, in vitro P. Andersson, J. Palmblad and T. Cederholm Department of Medicine, Stockholm Sdder Hospital, Department of Hematology and Department of Geriatric Medicine, Huddinge Hospital, Stockholm, Sweden.

Mean + SEM. No statistical difference was seen.

Interferon gamma (pg/g)

SMT

insufficiency whereas blockage of iNOS mediated NO production did not have this effect. Therefore, we conclude that the cNOS mediated NO pathway plays a crucial adaptive role in the response of the organism to counteract endotoxemia.

Bacterial translocation: CFU/gram organ: Spleen

NAME 50

Conclusions: Inhibition of cNOS mediated NO production led to renal

Results:

Liver

NAME 25

Mean _+SEM. Arterial urea in mM, urea flux in tJmol/100g/min. Negative flux means uptake, positive flux means production.

Clinical and experimental studies indicate that enteral nutrition has advantages over parenteral nutrition during surgical stress. To examine the underlying mechanisms, we investigated bacterial translocation and cytokine responses in a rat model of peritoneal inflammation. Methods: Twelve rats were divided into a total parenteral nutrition (TPN) group and a total enteral nutrition (TEN) group. They received TPN solution or an isocaloric and isonitrogenous peptide enteral diet for four days. Animals were then challenged intraperitoneally with zymosan to induce peritoneal inflammation. Eighteen hours after zymosan challenge, rats were gavaged with 108 E. coil and sacrificed four hours later. The liver, mesenteric lymphnode (MLN), spleen and blood were harvested. Bacterial translocation was evaluated by counting colony forming units of bacteria (CFU) in the organs. Cytokine levels in the sera, liver and MLN were determined by ELISA.

MLN

LPS

MLN

Mean -+SEM. ND: not detected. *P< 0.05. l-P= 0.09 vs TEN.

Conclusion: Although this animal model showed minimal changes in translocation of viable bacteria, TPN vs TEN resulted distinctly different cytokine responses. This difference in cytokine responses may, in part, explain the benefits of enteral nutrition during inflammatory stress. 57