Our previous study demonstrated that combination treatment with cetraxate plus omeprazole, amoxicillin, and clarithromycin is effective for the eradication of Helicobacter pylon in smokers. To evaluate the effect of cetraxate on gastric mucosal blood flow (GMBF) and the gastric concentration of clarithromycin in nicotine-treated rats, 10 rats were divided into two groups given nicotine with or without cetraxate, and GMBF was measured by laser Doppler blood flowmetry. Another 36 rats were divided into three groups (control, nicotine, and nicotine + cetraxate). Clarithromycin was administered intraduodenally and nicotine was administered after 30 minutes, with cetraxate being given 30 minutes later. The gastric mucosal clarithromycin concentration was measured. After cetraxate administration, GMBF increased significantly in the nicotine + cetraxate group compared with the nicotine group (p<0.05). The mucosal clarithromycin concentration increased in the nicotine + cetraxate group compared with the nicotine group, but the difference was not significant. Our results indicate that cetraxate increased GMBF in nicotine-treated rats