Despite an enhanced HO-1 mRNA expression after stimulation with ASA HO-1 protein induction failed to appear - most likely due to the toxicity of the drug. Stimulation with vitamin C increased expression of both mRNA and protein especially in ASA stimulated cells - therefore gastroprotection by vitamin C could be - at least in part - mediated by HO-1.

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Induction of Urokinase-Type Plasminogen Activator and Its Receptor in the Gastric Fibrohlasts and Effects of Nonsteroidal Anti-Inflammatory Drugs and Prostaglanflin Jun-lchi Iwamoto, "fuji Mizokami, Kimiko Takahashi, Takeshi Matsuoka

Background: In acute inflammatory condition, little is known about the expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in gastric fibrohlasts. Aims and Methods: To clarify the role of the human gastric fibroblasts in acute inflammatory conditions such as gastric ulcer, the effects of IL-I[~ and TNF--a on the production of urokinase-type plasminogen activator (uPA) and its receptor, which were suggested to be associated with tissue remodeling, by the gastric fibroblasts were investigated. The effect of indomethacin on uPA and its receptor expression by those cells was also examined. Further- more, we investigated the role of PGE2, which is suggested to play major roles in the stomach, on uPA and its receptor production by the gastric fibroblasts. Results: The expression level of uPA mRNA and the amounts of uPA antigens increased significantly by the treatment with each concentration of IL-I[~ (land 10 ng/ml) and 10 ng/ml of TNF-a. The expression level of uPA receptor mRNA increased in dose-dependent manner with each concentration of IL-l[~(landl0 ng/ml). When the gastric fibroblasts were treated with 50 g.M of indomethacin, expression level of the uPA mRNA decreased significantly, and the amounts of uPA antigens into the culture medium and on the cell surfaces decreased significantly by indomethacin in a dose-dependent manner. The increased uPA receptor mRNA expression by 1L-I[~ was reduced to the basal level by treatment with 50 pM of indomethacin. The expression level of uPA receptor mRNA and the amounts of uPA antigens on the cell surfaces increased in a dose-dependent manner by the treatment with PGE2 (10 and 50 g.M )Fig .Conclusions: These results suggested that uPA and its receptor production by the gastric fibroblasts is involved in the regulatmg system of PGE2, and that NSAIDs may delay healing of gastric mucusal injury in part through suppressing the uPA production via inhibition of the endoge- nous PG production.

Expreulon of uPA and b recoplar

tre~mmt f.m L.lpl0ng/ml IL.lpt0ngJml I~E210pM PGF.2501JN

INDSOIJM uPAmRNA 0.76~0.19 1.08~0.08 0.66~0.07 uPAR mRNA 0.41:0.04 1.02,0.29 0.63~0.16 1.01~0.12 1.18,0.06 uPA pro- ~ ( ~ ) secreted 4.78~0.55 8.55,0.07 6.26~0.96 4,30~0,44 4.52~0.87 cell eurfizcU 2.50~0.14 2.53,0.23 2.04~-0.06 3.43~0.12 3.58,0.12

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Histology of Mucosai Damage Induced by Amtolmetin Guacyl, Tolmetin and Celecoxib dur ing lschemia-Reperfusion in the Rat Stomach Giuseppina Morini, Daniefa Grandi, Gabriella Coruzzi, Karlheinz Ehrfich, Btigitta M. Veskar

BACKGROUND: We have previously shown that amtolmetin guacyl (AMG) which inhibits cyclooxygenases (COX) and upregulates inducible nitric oxide synthase (iNOS) in the gastric mucosa does not aggravate macroscopic mucosal damage in rats during ischemia-reperfusion (l-R). In contrast, the AMG metabofite tolmetin does not induce iNOS and markedly aggra- vates gross I-R injury. This study evaluates the histological changes induced by AMG, tolmetin and the COX-2 inhibitor celecoxib in gastric tissues during I-R. METHODS: In rats (3-6/group), the celiac artery was clamped for 30 min. After 60 min reperfusion, the glandular mucosa was processed for light and transmission electron microscopy. Rats were treated po with AMG (300 mg/kg), tolmetin (61 mg/kg) or celecoxib (3 mg/kg). Other rats received the drugs without I-R and damage was assessed 5.5 h later. RESULTS: Histological examination revealed that I-R damages almost exclusively the upper region of the gastric mucosa. Production of mucus by surface mucous cells (SMC) was sharply decreased and their cytoplasm was hyaline (grade 1 damage). This alteration involved 80% of the total length of tissue examined. Exfoliation of SMCs (grade II damage) involved 12% of the tissue. Uhrastructural changes in superficial microvessels were observed, the most relevant features being the increased thickness and the luminal projections of endothelium. AMG did not modify damage by I-R By contrast, tolmetin increased the severity of damage by I-R. Areas exhibiting grade 11 damage were 42% of the tissue (P < 0.01 vs [-R alone). About 14% of the t ~ u e exhibited necrotic lesions deeply extending into the gastric glands (grade Ill damage) which were not observed in the stomachs with I-R and I-R plus AMG. Damage by 1-R was even more impressively worsened following celecoxib. Areas showing grade 11 and grade Ill damage were 32% (P < 0.01 vs I-R alone) and 24% (P < 0.05 vs I-R plus tolmetin) of the tissue, respectively. AMG, tolmetin and celecoxib without I-R induced a slight vasocongestion and/or infiltration by inflammatory cells. CONCLUSIONS: 1) Whereas AMG does not aggravate I-R injury tolmetin and celecoxib in doses with comparable anti- inflammatory activity significantly increase damage with the occurrence of deep necrotic lesions. 2) The findings suggest that increased formation of endogenous NO resulting from induction of iNOS induced by AMG counteracts the damaging effect of COX inhibition not only at the macroscopic but also at the histological lev

$1203

Interaction of Helicobacter pylori (Hp) with NSAID and coxibs on healing of preexisting gastric ulcerations in rats Stanislaw J. Konturek, Thomas Brzozowski, Peter C. Konturek, Wladyslaw Bielanski, Jerzy Stachura, Marzena Mierzwa, Wieslaw W. Pawlik, Eckhart G. Hahn

Hp and nonsteroidal anti-inflammatory drugs (NSAID) such as aspirin (ASA) act as two independent risk factors of gastric ulcerogenesis but the interaction between Hp and ASA or the new class of specific COX-2 inhibitors (coxibs) remains unclear. We compared the effects of inoculation with viable Hp obtained from type I (cagA+;vacA +) germs or vehicle (saline) in annnals with gastric ulcers induced by acetic acid technique (ulcer area 28 ram2) and administered i.g. with or without acidified aspirin (ASA 50 mg/kg-day) or rofecoxib (10 mg/kg-day), a specific COX-2 inhibitor, that started one week upon Hp (series A) or prior to Hp or saline inoculation (series B). Animals were killed at day 12 and 20 upon Hp inoculation and the area of gastric ulcers was measured by planimetry, gastric blood flow (GBF) was determined by H2-gas clearance method and blood was withdrawn for the determination of plasma gastrin levels by RIA and plasma levels and mucosal expression of proinflammatory cytokines such as IL-113 and TNFa was analyzed by ELISA and RT-PCR Gastric ulcers healed gradually in vehicle-treated controls with an ulcer area at day 12 and 20 days being reduced by 63% and 95%. Inoculation with Hp (3x106 CFU, 3 times) or acidified ASA or rofecoxib delayed significantly ulcer healing and these effects were accompa- nied by the fall in the GBF at ulcer margin, the upregulation of [L-113 and TNFtx mRNA and 2-3 fold increase in their plasma levels. Application of ASA or rofecoxib to Hp-infected rats (series A) attenuated significantly the area of gastric ulcers and plasma IL-113 and TNFct levels and produced a significant rise in the GBF at ulcer margin as compared to those treated with acidified ASA alone. In contrast, when ASA or rofecoxib was administered 5 times prior to subsequent inoculation with Hp (series B), the ulcer area and plasma IL-I[3 and TNF~t were significantly elevated and the GBF at ulcer margin was significantly diminished as compared to those in Hp inoculated animals. We conclude that 1) an impairment in the GBF in the ulcer area and overexpression and release of IL-I~ and TNFa contribute to the prolongation of ulcer healing induced by viable Hp in the rat stomach; 2) Hp-induced gastric inflammation may limit the deleterious effect of ASA and rofecoxib on ulcer healing suggesting protective action of preexisting Hp infection against NSAID injury and 3) delayed healing in rats treated with ASA and rofecoxib and then exposed to Hp may reflect the failure in gastric adaptation to these NSAID in Hp-infected gastric mucusa.

$1204

A Novel Vitamin E Derivative (TMG) Protects Aspirin-Induced Gastric Mucosal Injury in Rats Hiroshi Ichikawa, Tomohisa Takagi, Naoya Tomatsuri, Hiroshi Higashihara, Kazuhiro Katada, Yutaka Isozaki, "fuji Naito, Norimasa Yoshida, Hironobu Murase, Toshikazu Yoshikawa

There is strong evidence that oxygen-derived free radicals produced by neutrophils are implicated in the production of aspirin-induced gastric mucosal injury. It has been reported that a novel vitamin E derivative, 2-(u-D-glucopyranosyl) methyl-2,5,7,8-tetramethylchro- man-6-ol (TMG), is somewhat located within the membrane surface and acts as a powerful antioxidam by scavenging radicals generated either in the aqueous or in the lipid phase. The purpose of this study was to investigate the antioxidative effects of water-soluble vitamin E derivative, TMG, which has excellent water-solubility (>1 x 103 mg/ml), on aspirin- induced gastric mucusal injury in rats. Aspirin-induced mucosal injury was produced by the intragastric administration of aspirin (200 mg / kg) and HCI (0.15 N, 8.0 ml / kg). At 3 h after administration of aspirin the animals were killed by exanguination via the abdominal aorta. TMG was dissolved in physiological saline at a dose of 0.1 - 10 mg/kg, and was given to the rats by intraperitoneal injection 1 h before the aspirin administration. The intragastnc administration of acidified aspirin induced hyperemia and hemorrhagic erosions in rat stomachs. The increase in the total gastric erosive area after aspirin administration was significantly inhibited by treatment with TMG in a dose-dependent manner. The concentra- tion of thiobarbituric acid-reactive substances (TBA-RS) in the gastric mucosa, an index-of lipid peroxidation, was also significantly higher than the basal level after aspirin administra- tion. This increase in TBA-RS in the gastric mucosa was inhibited by pretreatment with TMG. Furthermore, myeloperoxidase (MPO) activity in the gastric mucosa, an index of neutrophil infiltration, significantly increased by aspirin administration, and pretreatment with TMG significantly reduced this increase. The content of mucosa] CINC-1 in the control groups was significantly increased compared with the levels of that in the sham groups. This increase of the level of CINC-1 was significantly inhibited by the treatment with TMG at a dose of 10 mg/kg. Based on these data, the beneficial effects of TMG on aspirin-induced gastric mucosal injury may be attributed to its anti-inflammatory properties.

$1205

Indomethacin Up-regulates TFF2 Expression in Gastric Epithelial Cells Tadahito Shimada, Ayako Koitabashi, Takashi Hashimoto, Kumi Hosaka, Kyoko Tabei, Masashi Yoneda, Hideyuki Hiraishi, Akira Terano

BACKGROUND: Trefoil factor family (TFF) is a family of peptides which bear the three- loop trefoil domain. TFF peptides (TFF1, TFF2, and TFF3) are mainly expressed in the gastrointestinal tract and play important roles in gastrointestinal mucusal defense and repair. Although gastric epithelial cells are known to express TFF1 and TFF2 peptides, regulatory mechanisms of TFF expression are not fully understood. In the present study, we examined the effect of indomethacin, a non-selective inhibitor of cyclooxygenase (COX), on TFF mRNA expression in gastric epithelial cells. METHODS: MKN45, a cell line derived from gastric cancer, was used as a model of gastric epithelial cells. Other gastric cancer cell lines (AGS and JR) were also used in some experiments. Endogenous TFF1, TFF2, and TFF3 mRNA expression was analyzed by real-time quantitative RT-PCR. Beta-actin mRNA measurement was also performed for standardization. For luciferase reporter gene assay, 5'-flanking regions of TFF1 gene (-956 to +34), TFF2 gene (-912 to +24), and TFF3 gene (-957 to +12)

AGA Abstracts A-172