Splenic complications in chronic pancreatitis: Prevalence and risk factors in a medical-surgical series of 500 patients

Splenic complications in chronic pancreatitis: Prevalence and risk factors in a medical-surgical series of 500 patients

GASTROENTEROLOGY Vol. 114, No. 4 A482 AGA ABSTRACTS G1961 SPLENIC COMPLICATIONS IN CHRONIC PANCREATITIS: PREVALENCE AND RISK FACTORS IN A MEDICAL-SU...

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GASTROENTEROLOGY Vol. 114, No. 4

A482 AGA ABSTRACTS G1961

SPLENIC COMPLICATIONS IN CHRONIC PANCREATITIS: PREVALENCE AND RISK FACTORS IN A MEDICAL-SURGICAL SERIES OF 500 PATIENTS. D. Malka, P. Hammel, P. L~vy, A. Sauvanet°, P. Ruszniewski, J. Belghiti°, P. Bernades. Gastroenterology and °Surgery Departements, HSpital Beaujon, 92118 Clichy, France. Backoround: to assess the prevalence, course, treatment, outcome, and risk factors of splenic complications in chronic pancreatitis. Method: patients with and without splenic complications in a medical-surgical series of 500 consecutive patients with proven chronic pancreatitis prospectively followed up a mean time of 7.0 years were compared. Results: 11 men (2.2%) with alcoholic chronic pancreatitis (median duration: 2 years; range:0-5) had a splenic complication: intrasplenic pseudocyst (n=5), subcapsular hematoma (n=2), or rupture (n=4). All patients except one underwent splenectomy, 5 of whom also underwent distal pancreatectomy. No deaths occurred. Patients with splenic complications had pancreatic tail necrosis (54.5% vs 17.4%, P=0.007), distal pseudocyst (54.5% vs 11.7%, P=0.0009), or splenic vein occlusion (63.6% vs 10.8%, P < 0.0001) more frequently than those without. In the 22 patients who had the two latter lesions, the prevalence of splenic complications was 18.2% (odds ratio: 15.0; 95% confidence interval:4.0-55.7). Conclusion: splenic complications occur early in the course of chronic pancreatitis, are rare, and are favoured by splenic vein occlusion, and pseudocyst or necrosis of the pancreatic tail. Surgical treatment is usually required. G1962 EFFECTS OF PHOSPHOLIPIDS AND SPHINGOLIPIDS IN THE INDUCTION OF APOPTOSIS IN PANCREATIC AR42J CELLS. A. Masamune. T. Shimosegawa, M. Fujita, M. Koizumi, and T. Toyota. Third Dept. of Internal Medicine, Tohoku University School of Medicine, Sendal 980-77 Japan Recent investigations have suggested roles of acinar cell injury through apoptosis in the pathogenesis of acute pancreatitis. Intracellular mechanism of acinar cell apoptosis is largely unknown. Sphingolipids and phospholipids have been shown to mediate several cellular functions. For example, hydrolysis of sphingomyelin to ceramide, termed sphingomyelin pathway, mediates apoptosis, differentiation and inflammation in certain types of cells. In this study, we examined whether phospholipids and sphingolipids induce apoptosis in rat pancreatic AR42J ceils. (Methods) Rat pancreatic AR42J cells were treated with C2-ceramide (C2-cer; a cell-permeable analogue of ceramide), dihydro-C2-cer, sphingosine (Sph), sphingosine-l-phosphate (S-I-P), phosphatidic acid, phosphatidylcholine (PC), phosphatidylethanolamine (PE), platelet activating factor (PAF), lysoPC, lysoPAF, lysoPE, or lysophosphatidylinositol. Cell viability was assessed by MTT assay. Apoptosis was assessed by morphological studies, FACS analysis, and DNA agarose gel electrophoresis. (Results) C2-cer caused cell death in a time and dose-dependent manner. The effect was significant at concentrations above 5 NM. Sph caused cell death to lesser extent while Sph-l-P was ineffective up to 80 ~tM. Morphological changes characteristic of apoptosis (i.e., cell shrinkage and nuclear condensation) were observed. Apoptosis was confirmed by FACS analysis and internucleosomal DNA fragmentation. LysoPC, not PC, induced apoptosis in a similar manner to C2-cer. PAF and lysoPAF also induced apoptosis at concentrations as low as 2.5 pM while other sphigolipids or phospholipids were ineffective, suggesting their specific effects. (Conclusion) Our results suggest that possible roles of ceramide, lysoPC, PAF, and lyso PAF in the pathogenesis of acute pancreatitis through apoptosis. This study was supported in part by grants from Pancreas Research Foundation of Japan • G1963 ROLE OF ENDOTHELIAL ACTIVATION IN ACUTE PANCREATITIS. A. Masamune, T. Shimosegawa, M. Fujita, M. Koizumi, and T. Toyota. Third Dept. of Internal Medicine, Tohoku University School of Medicine, Sendal 980-77 Japan Multiple organ failure (MOF) is the most serious complication in acute pancreatitis. The mechanisms as well as the factors leading to MOF remain to be studied. We previously demonstrated enhanced expression of ICAM-1, suggesting involvement of endothelium in the pathogenesis of acute pancreatitis. In this study, we examined effects of ascitic fluids prepared from rats with experimental necrotizing pancreatitis on the (i) expression of cytokines, (ii) vascular tone, and (iii) microthrombus formation in human umbilical vein endothelial cells (HUVEC). (Methods) Experimental necrotizing hemorrhagic pancreatitis was induced in male Wistar rats (250 g wt) under general anesthesia by the retrograde injection of 5% sodium taurocholate into the pancreatic duct. At 24 h later, the peritoneal exudates were aseptically collected, centrifuged and HUVEC were treated with the supernatants. We examined (i) expression of interlenkin (IL)-6, IL-8 by enzyme-linked immunosorbent assay; (ii) induction of mRNA for these cytokines, endothelial isoform of nitric oxide synthase (ecNOS), endothelin-1, platelet-derived growth factor-B (PDGF-B), tissue factor, thrombomodulin by reverse-transcription PCR or Northern analysis, (iii)

activation of nuclear factor kappa B (NF-t:B), nuclear factor IL-6 (NF-IL6), cyclic AMP responsive element binding protein (CREB) by electrophoretic mobility shift assay. (Results) IL-6 and IL-8 expression in HUVEC was induced in a dosedependent manner. Compatibly pronounced mRNA expression for these cytokines, endothelin-1, PDGF-B, tissue factor was observed. In contrast, mRNA levels of ecNOS and thrombomodulin were downregulated. NF-•B, NF-IL6, and CREB were activated by the treatment, suggesting that ascitic fluids contain soluble factors transcriptionally activating the endothelium. (Conclusion) Our results suggest that endothelial activation such as cytokine expression, vascular contraction, and microthrombus formation may play roles in the pathogenesis of MOF in acute pancreatitis. This study was supported in part by grants from Pancreas Research Foundation of Japan • G1964 GROWTH

FACTORS IN THE REGENERATION OF EXPERIMENTAL PANCREATITIS. A. Menke, C. Philippi, H. Yamaguchi, H. Wecklein, and G. Adler. Internal Medicine I, University of Ulm, D-89070 Ulm, Germany

There is growing evidence that coordinated action of various growth factors and cytokines (IL) is necessary for successful tissue regeneration. We investigated the role of peptide growth factors in pancreatic regeneration following an acute pancreatitis. We have recently shown that TGF[3 1-3, as well as TGFI3 receptor proteins type I and II were overexpressed during regeneration and were involved in the stimulation of synthesis and deposition of the extracellular matrix. Methods: Messenger RNA expression of TGF[3 superfamily members (BMP2, -4, -9, activin 13a-e) and different peptide growth factors (TGFet, EGF, HGF, IGF-1, -2, FGF-1, -2, and PDGF B) and their correspondent receptors wer analyzed (between day 0 and 7) during regeneration after ceruleininduced experimental pancreatitis in the rat. The functional role of selected growth factors was investigated in cultured primary pancreatic epithelial cells, fibroblasts, and pancretic carcinoma cell lines. Results:. We could demonstrate an increased expression of BMP-2, BMP-7, but not BMP-4 during regeneration. Moreover activin fla, fie and 13e subunits showed elevated expression, wheras 13b mRNA levels remained unchanged. mRNA of mitogenic growth factors such as TGF0t, IGF-I, HGF, FGF-1 and FGF-2 were also overexpressed in pancreatic tissue during regeneration. Messenger RNA levels of the examined receptors of these growth factors were not altered, except c-met, the HGF receptor, expression of which and protein concentration was elevated. The proliferative effect of HGF and IGF-1 on epithelial cells of the pancreas was demonstrated in cultured cells. In case of FGF-2 the expression of various ECM proteins such as collagen I, III and flbronectin was stimulated in cultured pancreatic fibroblasts, costimulation with TGFI31 resulted in additional increase in collagen synthesis and production. Conclusions: In pancreatic regeneration a large number of different growth factors are overexpressed. FGF-2 together with TGFI3 stimulates the expression of the ECM, whereas IGF-1 and HGF seem to be involved in the proliferation control of epithelial ceils. This work was supported by the Deutsche Forschungsgemeinschaft, Kn200. • G1965

ACUTE PANCREATITIS AND PANCREATIC FIBROSIS IN RATS AFTER SINGLE TREATMENT WITH DIBUTYLTIN DICHLORIDE (DBTC) IN DEPENDENCE ON DOSE AND TIME. J. Merkord, H. Weber*, G. Sparmann**, G. Hennighausen. Institute of Experimental and Clinical Pharmacology and Toxicology, *Institute of Clinical Chemistry /Pathobiochemistry, **Dep. of Medicine, University of Rostock, Germany Dibutyltin dichloride (DBTC, 6 mg/kg b.w.i.v.) induce acute pancreatitis in rats. The pathogenesis and the natural course of the lesion has been described in detail (Merkord et al, Pancreas 15, 392-401, 1997). Methods: In the present study the dependence of the lesions of rat pancreas on the dose of DBTC (single i.v. administration of 4 mg/kg, 6 mg/kg and 8 mg/kg) and on the time after treatment (1 day to 24 weeks) has been investigated. The pathohistological changes of the pancreas were examined by light- and electronmicroscopy 1 and 7 days and 2, 4, 6, 9, 12, 15, 18, 21 and 24 weeks after administration of DBTC. Furthermore pathobiochemical parameters of pancreatitis (amylase and lipase activity in serum), liver lesions (AP and bilirubin in serum) and of fibrosis (hydroxyproline in urine and hyaluronic acid in serum) were studied and the concentration of tin in the tissues was measured, mRNA expression was analysed by Northern blotting. Results: 1 day after administration of a single dose of DBTC (4, 6 and 8 mg/kg i.v.) an acute interstitial pancreatitis had developed. 4 weeks after administration of 4 mg/kg DBTC a complete restitution was observed. The higher doses of DBTC (6 and 8 mg/kg i.v.) induced at the same time an interstitial and periductal fibrosis. 8 weeks after administration of 8 mg/kg DBTC i.v. we could demonstrate elevated serum levels of HA, increased mRNA expression of collagen type I as well as TGFI31, infiltration of lymphocytes and macrophages and an extended pancreatic fibrosis. 24 weeks after administration of 6 mg/kg DBTC i.v. 50% of rats and after