A1106 AGA ABSTRACTS

5116

SERUM LEVELS OF PROGASTRIN BUT NOT AMIDATED GAS­TRIN OR GLYCINE-EXTENDED GASTRIN ARE ELEVATED INPATIENTS WITH COLORECTAL NEOPLASIA.Karim B. Muhammad, Ravindra K. Siddheshwar, Janine Gray, Seamus B.Kelly, North Tyneside Gen Hosp, Newcastle, United Kingdom; WansbeckGen Hosp, Ashington, United Kingdom; Ctr for Health and Med Research,Middlesbrough, United Kingdom.

Aim: To determine whether fasting serum levels of progastrin, amidatedgastrin and glycine-extended gastrin are elevated in patients with colorectalcancer or colorectal polyps compared to controls. Background: It has beenshown that fasting serum amidated gastrin levels are elevated in patientswith colorectal cancer and decrease after apparently curative resection ofthe tumor. However, these studies failed to control for H.Pylori infection(a known cause of hypergastrinaemia). When confounding factors whichincrease serum gastrin levels are taken into account, it has been shown thatserum gastrin levels are not elevated in patients with colorectal cancer.These studies have only measured amidated gastrin and not the moreimmature forms of gastrin. Total gastrin, which includes all unprocessed,partially processed and mature forms of gastrin has been shown to beelevated in patients with colorectal cancer. Methods: This study included57 patients with colorectal cancer, 29 patients with colorectal polyps and53 controls. Controls included symptomatic patients who underwentcolonoscopy and were found to have normal mucosa or mild diverticulardisease. Patients and controls with factors known to raise plasma gastrinlevels were excluded from the study. Fasting serum levels of progastrin,amidated gastrin and glycine-extended gastrin were measured by radioim­munoassay. H.Pylori antibodies were measured by ELISA test. Statisticalanalysis was by Kruskal Wallis test. Results: This study shows that patientswith colorectal cancers have elevated median levels of progastrin (27.5pM) compared to polyps (:515 pM) or controls (:515 pM), (p=O.OOOI).There was no difference in amidated gastrin between cancer (median 13pM), polyp (median 24 pM) or control (median 10 pM). H.Pylori positivepatients had high amidated gastrin levels (median 19 pM) (p=0.OO22). Nosignificant effect of H.Pylori on progastrin was seen. Median progastrinwas significantly elevated in moderately dysplastic polyps (median 38 pM)compared to mildly dysplastic (median 15 pM) or severely dysplastic(median 15 pM) polyps, (p=0.05). There was no difference betweenmedian levels of progastrin and amidated gastrin in relation to sex, polyptype, cancer site, grade or Dukes' staging. Glycine-extended gastrin levelswere below the limit of detection «20 pM) in all groups. Conclusion:Progastrin levels are elevated in patients with colorectal cancer comparedto patients with polyps or controls.

5117

EFFECT OF NICOTINE ON EXPRESSION OF NACHR ONCD4+CELLS OF SPLENOCYTES AND THYMOCYTES IN OX­AZOLONE-INDUCED COLITIS OF MURINE MODEL.Yuhji Murata, Jugoh Itoh, Ying Han, Akihiro Munakata, Yutaka Yoshida,Aomori Gen Hosp, Aomori, Japan; First Dept Medicine Hirosaki Univ Schof Med, Hirosaki, Japan; Dept Gastroenterology, Beijing Army Gen Hosp,Beijing, P. R. China; Hirosaki Univ, Hirosaki, Japan.

Aim:We have shown that nicotine enhance Thl-derived cytokine in DSS­induced colitis and suppress Th2-derived cytokine in oxazolone(OXZ)­induced colitis. The presence of nicotinic acetylcholine receptor (nAchR)on lymphocytes has been demonstrated and nicotine may influence thefunction of lymphocytes through nAchR on their surface. However, nostudy has investigated the expression of nAchR of lymphocytes fromspleen and thymus in murine models of IBD. The present study attemptedto elucidate the possible role of nAchR in nicotine-related effect on IBD.Methods: 6 mg of OXZ(in 50% ethanol) was intrarectally administered inSJL/J mice to induce colitis. In nicotine group, 0.5mg/kg/day of nicotinewas injected subcutaneously for three weeks. Isolated splenocytes andthymocytes as well as lamina propria lymphocytes(LPL) from small intes­tine were incubated with 0.1U/ml of cholinesterase for over 8 hours andresuspended . Cells were stained with FITC-conjugated nornicotine (I X lO,4M) and PE-conjugated anti-CD4, and analyzed by FACS. Results:The percentage of FITC-Iabeled nornicotine binding to splenocytes afterthe addition of nAchR antagonist mecamylamine in each concentrations ofI X lO'4M, I X lO'3M and I X IO'2M was 94.8% ,60.9% and 8.3% respec­tively, indicating that nornicotine is able to bind with nAchR specifically.About 90-95% of splenocytes, thymocytes and LPL expressed nAchR ontheir surface.In OXZ-induced colitis, the percentage of CD4 +nAchR+cellsin splenocytes (33.9::':1.0%) or thymocytes(50.7::':8.4%) tend to decreasecompared with controls(55.3::':lO.l% and 80.9::':2.1%, respectively), butthe nAchR on CD4+ cells expressed quantitatively as mean fluorescenceintensity (MFI) had no significant change in either splenocytes(126.8::':17.7) or thymocytes (62.8::':6.9, respectively) compared with con­trols (118.9::':23.6 and 86.2::':8.9, respectively). In nicotine group, com­pared with OXZ group, the decreased proportion of CD4 + nAchR+cellswas up-regulated in splenocytes(45.3::':3.7) and thymocytes (58.3::':2.7%),and amount of nAchR on CD4+ cells was down-regulated in spleno­cytes(75.9::':24.4) but was up-regulated in thymocytes (157.7::': 17.7). Con­clusion: Nicotine could affect cytokine production by lymphocytes througha specific binding with nAchR on their surface; colonic inflammation mightinfluence CD4+nAchR+cells; and nicotine might have an inhibitory effecton the expression of nAchR on CD4 +cells of splenocytes but a stimulatoryeffect on that of thymocytes.

GASTROENTEROLOGY Vol. 118, No.4

511S

INVOLVEMENT OF THE SMALL GTP BINDING PROTEIN, RHOA AND THE CELL -CELL ADHERENCE PROTEINS, E-CAD·HERIN AND B-CATENIN IN SIGNALING PATHWAY OF PAN­CREATIC ACINI.Fumihiko Nozu, Shigeki Tanaka, Keiji Mitamura, Showa Univ Sch ofMedicine, Tokyo, Japan.

Background: Several lines of evidence have suggested that the actincytoskeleton is regulated by Rho family proteins. We previously reportedthat Rho A is involved during stimulus-secretion coupling of pancreaticacini (Am. 1. Physio!. 276:G915-G923, 1999). Although the actin cytoskel­eton is known to play important roles in pancreatic acinar cell, its precisemechanisms are still uncertain. On the other hand, the roles of cell-celladherence proteins, E-cadherin and ,B-catenin remain to be determined inpancreatic acini. Aim: In this study, we aimed to evaluate the interactionof Rho A, E-cadherin and ,B-catenin in signaling pathway of pancreaticacini. Methods: Pancreatic acini were incubated with or without chole­cystokinin-octapeptide (CCK-8), carbachol (CCh) and 12-0-tetradecanoyl­phorbol 13-acetate (TPA). Western immunoblotting and immunoprecipi­tation of solubilized rat pancreatic acini were performed. Isolated aciniwere used for immunohistochemical study. Results: Using anti-Rho Aantibody, anti-E-cadherin antibody and anti-,B-catenin antibody, clearbands were detected at the location of 21 KDa, 115 KDa and 90 KDa,respectively. CCK-8 (10 pM-lO nM) enhansed these bands from 3 min andsustained up to 30 min after stimulation. CCK-8 (10 pM-lO nM) and CCh(100 nM-lOO p.M) biphasically increased and TPA (10 nM-Ip.M ) dose­dependently increased the intensities of Rho A bands. CCK-8 (10 pM-lOnM), CCh (100 nM-lOO p.M) and TPA (10 nM-Ip.M ) dose-dependentlyincreased the intensities of E-cadherin and ,B-catenin bands. Removal ofextracellular Ca2+ during CCK-8, CCh and TPA stimulation inhibited theincrease of E-cadherin bands. In immunoprecipitation study, E-cadherinformed imrnunocomplex with ,B-catenin after CCK-8 (10 nM) and CCh(lOOp.M) stimulation and Rho A also formed immunocomplex with ,B-cate­nin after CCK-8 (10 nM) and CCh (lOOp.M) stimulation. Immunohisto­chemical study indicated that Rho A localized in acinar luminal portion andE-cadherin and ,B-catenin localized in the basolateral portion after CCK-8stimulation. Conclusion: Our study suggest that the activation and inter­action of Rho A, E-cadherin and ,B-catenin are involved in signalingpathways of rat pancreatic acini evoked by CCK and CCh.

5119

FOLLOW-UP OF VAGAL FUNCTION IN DIABETIC PATIENTSAFTER PANCREAS TRANSPLANTATION.B. Otto, S. Kiehler, RI Riepl, C. Dieterle, R. Landgraf, Clin InnenstadtLudwig Maximilians Univ, Munich, Germany.

During insulin-induced hypoglycemia a strong increase of pancreaticpolypeptide (PP) - a hormone under vagal control - is observed in healthysubjects. This increase can be abolished after truncal vagotomy or atropine.It has been shown that only in diabetic patients with an intact autonomicnervous system a postprandial increase of PP was observed. The intentionof our study was to show whether autonomic neuropathy (vagal function)improves after pancreas transplantation in longstanding type I diabeticpatients. Methods: In 12 patients (8 male, 4 female; 44.7::':8.2 years;mean::':SD) autonomic neuropathy was tested in a follow-up design:2.9::':1.1 months (test A) and 20.6::':4.8 months (test B) after pancreastransplantation. After given written informed consent, vagal neuropathywas screened by measuring PP-increase during insulininduced hypoglyce­mia (0.15 IV insulin/kg body weight). Plasma PP concentrations weremeasured in regular intervals with an established radioimmunoassay. Re­sults: There was no significant difference in serum creatinine (A: 1.2::':0.2mg/dL, B: 1.3+-0.2 mg/dL), HbAI (A: 5.5::':0.6 %, B: 6.1 ::':0.6 %) or basalPP levels (A: 10.5::':4 pmollL, B: 18.2::':11.2 pmollL) at both time points.In two patients the insulinhypoglycemia-test had to be interrupted becauseof prolonged hypoglycemia. Early after pancreas transplantation (test A) nosignificant increase of plasma PP concentrations during hypoglycemia(delta after 30 min: -0.6::':2.9 pmol/L; delta after 45 min: 1.5::':5.2 pmollL)was observed. There was also no significant difference in hypoglycemia­induced PP release in test B (delta after 30 min: -2.0::':10.3 pmol/L; deltaafter 45 min: 4.1 ::':9.0 pmol/L). Conclusions: No improvement of vagalfunction could be observed in patients after successful pancreas transplan­tation (20.6:+ - 4.8 posttrmsplant.). It may be speculated that autonomicneuropathy of the vagus needs a longer time for recovery.

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PHAGOCYTIC KILLING OF THE PERITONEAL MACRO­PHAGES IS ENHANCED BY THE SIGNAL VIA MAC-t (CD11BICDtS).Tetsuhiro Owaki, Sonshin Takao, Takashi Aikou, Gregory B. Bulkley,Andrew S. Klein, 1st Dept of Surg, Kagoshima Univ Sch of Medicine,Kagoshima, Japan; Kagoshima Univ Sch of Medicine, Kagoshima, Japan;Johns Hopkins Med Inst, Baltimore, MD.

INTRODUCTION Mac-I (CD29/CDllb, CR3), a beta2 integrin expressedon macrophages (Mfs), is important in adhesion to endothelial cells. Mfshave a phagocytic and phagocytic killing function, and these functionsrequire the adhesion with foreign substances. In the previous study, Mac-Iaffected the phagocytic function of Mfs, and increased superoxide anion(Oi) generation in neutrophils. Therefore we investigated phagocytic kill-