A1250 AGA ABSTRACTS

5720

AMMONIA STIMULATES PEPSINOGEN RELEASE FROM PEP·TIC GLANDS VIA CAH MEDIATED PATHWAY.Masaki Inoue, Tomohiko Shimatani, Yoko Horikawa, Yukinobu Kawai,Goro Kajiyama, Hiroshima Univ Sch of Med, Hiroshima, Japan,

AIM: The physiological role of H.pylori on gastric secretion has not yetbeen ascertained. To clarify it, we investigated the effects of ammonia onpepsinogen secretion. SUBJECTS AND METHODS: Peptic glands iso­lated from the bullfrog (Rana catesbeiana) esophagus were prepared byenzymatic digestion, which was mounted in a perfusion chamber. It wasperfused with Amphibian Ringer medium. Pepsinogen secretion was ex­amined for 30 minutes with 2 min intervals. Pepsinogen secretion wasmeasured with a hemoglobin digestion method at pH2. After the observa­tion of basal pepsinogen secretion, various concentration of NH4Cl (3­90mM) was added to the medium. In the other experiments, several drugswere used as follows; I) IOJ.LM carbonyl cyanide m-chlorophenylhydrazone(CCCP), which is an uncoupler of oxidative phosphorylation in mitochon­dria + 50mM NH4CI 2)Ca2+ free medium with ImM EGTA + 50mMNH4CI3)100J.LM LaCI3 .which is an non-selective Ca2+ channel blocker +50mM NH4CI 4) 100J.LM W-7 , which is a specific calmodulin antagonist +50mM NH4Cl 5)30J.LM bethanechol + 50mM NH4CI. The viability ofpeptic glands was assessed by a trypan-blue exclusion test. RESULTS:I)NH4CI (3-90mM) induced an increase of pepsinogen secretion time- andconcentration-dependently. After treatment for 15min, 90mM NH4CI in­duced about 2-fold increase in pepsinogen secretion over controls(p<O.OI). 2)Glands viability was not affected by NH4CI of these concen­trations. 3)pepsinogen secretion stimulated by 50mM NH4Cl was reducedby 10J.LM CCCP. 4)Ca2 + free medium with ImM EGTA or 100J.LM LaCl3reduced pepsinogen secretion by 50mM NH4CI. 5)50mM NH4CI stimula­tion was reduced by 100J.LM W-7. 6)50mM NH4CI enhanced the stimula­tory effect of the pepsiongen secretion by 30J.LM bethanechol. CONCLU­SIONS: These results suggest that ammonia stimultates gastric pepsinogensecretion in a time- and concentration-dependent manner, and this effect isnot toxic, requires extracellular Ca2 + influx, and is mediated via thecalcium dependent pathway.

5721NORMALIZATION IN GASTRIC MUCOSAL PHOSPHATIDYL·CHOLINE AFTER ERADICATION OF HELICOBACTER PYLORIIN PATIENTS WITH PEPTIC ULCER.Sadatoshi Ishibashi, Ryuichi Iwakiri, Seiji Kawasaki, Jutarou Tadano,Kouji Fukuyama, Kayoko Oda, Keiji Matsunaga, Yudai Goto, HiroyukiSakata, Kazuma Fujimoto, Saga Med Sch, Saga, Japan.

Phosphatidylcholine(PC) is a principal phospholipid in the gastric mucosathat forms a hydrophobic layer in the gastroduodenal epithelium,and playsan important role in the gastric protective system. We previously reporteda decrease in the amount of PC in patients with peptic ulcer regardless ofHelicobacter pylori(H.pylori) infection (Gastroenterology 112:1056,1997).The aim of this study was to examine an effect of eradication of H.pylorion phopholipids including PC in patients with gastric and/or duodenalulcer. Methods: The endoscopic biopsy specimens were obtained from theantral and corporal mucosa of 18 H.pylori positive patients with pepticulcer to evaluate contents of phospholipids. We also obtained biopsyspecimens in patients with peptic ulcer without H.pylori infection(n= 13)and control subjects without H.pylori infection. H.pylori was eradicated inpatients with H.pylori infection. Three months after the eradication, theendoscopic biopsy specimens were again obtained for evaluation ofamounts of phopholipids. Phospholipids were measured quantitatively inthe lipid extraxt from the bipsy specimens according to thin-layer chro­matography and flame ionization detection method using Introscan TLC/FID analyzer. Result: The amount of phospholipids were evaluated in 17patients who were eradicated H.pylori successfully without relapse ofpeptic ulcer( 17 out of the 18 patients; 94.4%). Among phospholipids, PCdecreased significantly in patients with peptic ulcer regardless of H.pyloriinfection compared to normal control subjects( peptic ulcer with Helico­bacter infection: 6.2::+:0.2 micro-grams/mg; peptic ulcer without H.pyloriinfection: 5.6::+:0.3 micro-gram/mg; normal subjects without H.pylori in­fection: 7.6::+:0.3 micro-gram/mg). Other phospholipids evaluated in thepresent experiment were not differed significantly among the tested groups.The eradication of H.pylori recovered the amount of PC to the control levelin patients with peptic ulcer 3 months after the eradication (before theeradication: 6.2::+:0.2 micro-gram/mg, after the eradication: 9.6::+:0.2 micro­gram/mg). Conclusions: This study demonstrated that the eradication ofH.pylori inpatients with peptic ulcer recovered decrease in PC in the gastricmucosa to the control level. The eradication of H.pylori can lessen thedeteriolation of the protective system of the gastric mucosa, which mightbe one of reasons for prevention of recurrence in peptic ulcer after theeradication.

GASTROENTEROLOGY Vol. 118, No.4

5722THE ROLE OF SELECTIN IS IMPORTANT IN GASTRIC MICRO·CIRCULATORY DISTURBANCE INDUCED BY THERMAL IN·JURY IN RATS.Hideki Ishikawa, Masashi Yoshida, Masahiko Nakamura, Go Wakaba­yashi, Motohide Shimazu, Masaki Kitajima, Keio Univ Sch of Medicine,Tokyo, Japan; Kitasato Institute, Tokyo, Japan.

Leukocytes-endothelial interaction has large manner in microcirculatorydisturbance. In the present study, the role of selectin, one of the adhesionmolecules, on gastric microcirculatory disturbance induced by thermalinjury were studied. Methods: Male Wistar rats were anesthetized and a 30% full skin-thickness dorsal bum was inflicted. The animal experimenta­tion guidelines of the Keio University School of Medicine were followed.Sialyl Lewis X (SLeX) is known as a ligand of selectin family. For purposeof clinical use, we have developed a novel selectin antagonist; SLeXanalogue. The SLeX analogue group (4 mg/kg body weight, injected intojugular vein 30 min before and 2.5 hrs after the bum) and the vehicle group(administrated saline in the same manner) were studied 5 hours afterthermal injury. (I) Immunohistochemistry with fluorescein isothiocyanateconjugated E-selectin monoclonal antibody was studied. (2) Gastric mu­cosal lesions were obserbed under the stereoscopic microscope and thetotal lengths of mucosal lesions were measured. (3) Luminol-dependentzymosan-stimulated chemiluminescence (ChL) activity generated by leu­kocytes from jugular vein were measured. (4) Microvascular images in thebasal layer of gastric mucosa were observed through an intravital micro­scope. (5) Rolling leukocytes were calculated under the CCD camera. (6)Monastral blue B (MBB) was administrated intravenously to assess mi­crovascular endothelial damage. Results: (I) E-selectin was stronglystained at the luminal surface of venule in the vehicle group, whereas thestain was weak in the SLeX analogue group. (2) The percentage of rollingleukocytes was increaced 5 hours after thermal injury, and it was reducedin the SLeX analogue group. (3) Chemiluminescence activity generated byleukocytes was attenuated in the SLeX analogue group. (4) The percentageofMBB deposit areas was suppressed in the SLeX analogue group. (5) Thetotal length of mucosal lesions was supressed in the SLeX analogue group.(6) Venule walls were smooth in the control group, whereas irregularconstrictions tended to be observed in both the SLeX analogue group andthe vehicle group. Conclusion: It is suggested that selectin is involved ingastric microcirculatory disturbance after thermal injury. This novel selec­tin antagonist is an effective material to protect gastric microcirculation.(This work was supported by a Grant-in-Aid for Scientific Research fromthe Ministry of Education. Science and culture of Japan.)

5723MAST CELLS MAY STIMULATE FIBROSIS BY RELEASING BA­SIC FIBROBLAST GROWTH FACTOR (BFGF) IN THE BASE OFGASTRIC ULCER.Izumi Ishizuka, Shigemi Nakajima, Nobumichi Bamba, Mitsue Mura­matsu, Tadao K. Kobayashi, Ryoji Kushima, Tadao Bamba, TakanoriHattori, Shiga Univ ofMed Sci, Otsu, Shiga, Japan; Social Insurance ShigaHosp, Otsu, Shiga, Japan; Kusatsu Gen Hosp, Kusatsu, Shiga, Japan;Saiseikai Shiga Hosp, Ritto, Shiga, Japan.PURPOSE: Mast cells release various kinds of chemical mediators, andcontribute the process of inflammation and wound healing. Althoughincreased mast cells are observed in the stomach with gastritis or gastriculcer, precise roles of these mast cells are still unknown. To determine ifmast cells stimulate ulcer healing, we examined the relationship betweenmast cells and fibrosis in the base of gastric ulcer and demonstrated basicfibroblast growth factor (bFGF) in mast cells. MATERIALS AND METH­ODS: Resected stomachs from 6 patients with perforated gastric ulcer werestudied. Each stomach was fixed with 10% formalin and embedded inparaffin. Serial sections were cut and stained with hematoxylin and eosin(H&E) and elastica van Gieson (EVG) stains, and also stained immuno­histochemically with anti-human mast cell tryptase and anti-human bFGF.Intensity of fibrosis was evaluated semi-quantitatively in 5 grades in thebase and the surrounding area of gastric ulcer. Tryptase-positive mast cellnumbers were counted and the density of mast cells was calculated.Relationship between the intensity of fibrosis and the density of mast cellswere evaluated in the same area of serial sections. Cells stained positivelywith anti-bFGF were compared with cells stained with anti-mast celltryptase in serial sections. RESULTS: Granulation tissue with fibrosis wasobserved in the base and the surrounding area of gastric ulcer. Intensity offibrosis was significantly (p<O.OI) stronger in ulcer base (mean grade: 4.5± 1.7) than in surrounding area (mean grade: 2.0 ± 1.1). The mean mastcell density was significantly associated with the intensity of fibrosis(Spearman's value: 0.717. p<O.OI). Positive cells for bFGF were alsopositive for mast cell tryptase in serial sections. bFGF was stained in thegranules of cytoplasm. DISCUSSION: Intensity of fibrosis was signifi­cantly associated with the density of mast cells in the base and thesurrounding area of gastric ulcer. bFGF was positive in the granules of thecytoplasm. bFGF-positive cells were also positive for mast cell tryptase. Itis reported that mast cells were degranulating in the stomach with gastriculcer. Mast cells in the stomach with gastric ulcer might release bFGF bydegranulation, and stimulate the growth of fibroblasts. CONCLUSION:Mast cells may contribute to the healing of gastric ulcer by stimulatinggrowth of fibroblasts with bFGF.