Detection of cytoklne transcripts in rat gastric mucosa after exposure to stress using the reverse transcrlptase polymerase chain reaction. H. Ernst*, P. Konturek*, A. Ihlm, T. Brzozowski, E.G. Hahn* and S.J. Konturek. *Dept. of Med. I, Univ. Erlangen-Nuremberg, FRG and Inst. of. Physiol., Univ. Sch. Med., Krakow, Poland. Cytokines may contribute to the pathogenesis of stress ulcerations. They may be directly cytotoxic to epthelial cells, or may change the balance towards ulcer formation. Here we investigate the expression of several cytokine transcnpts after a single exposure to stress. Material and Methods: 25 rats were exposed to water restraint stress for 3.5h and then sacri!iced at O, 2, 4, 6 and 12h. The number of stress lesions were counted. Specimens were frozen in liquid nitrogen and total RNA was isolated. cDNA for RT-PCR was synthesized from RNA by reverse transcription using oligo(dT)priming. GAPDH, r~-actin, IL-la, IL-2, IL-6,1FN-¥, TNF-~ and TGFf51 transcripts were analysed by RT-PCR using specific primers. Results: The average number of ulcerations at Oh was 15±3 and then gradually declined to 4 ± 2 at 12h after stress. Controls for r~-actin and GAPDH showed equal expression of transcripts, except that GAPDH transcripts were not detectable 2 h after stress induction. No IL-2, TNF-ct, or IFN-y transcripts were detectable. IL-6 was found in the control group and was also detectable 4 and 6 h after exposure to stress and decreased to below normal levels at 12h. A week signal for ILla was detectable at 4 h after exposure to stress. In contrast, TGFf31 transcripts decreased at 0 and 2 h after stress and its levels did not differ from those of controls at 4, 6, and 1 2 h after exposure to stress. Conclusions: There is expression of a time-dependent pattern of cytokine gentranscripts after exposure to stress. This signaling of cytokines may reflect the normal biological response to stress. INFLUENCE OF BLOOD MICROCIRCULATION ON THE ACUTE NSAID-INDUCED GASTRIC INJURY. J. Esteban*. M.A. Rodriguez*, LR. Aracama*, C. del Pine*, M.J. Martin**, V. Motilva**, C. Alarc6n**, D. Delgado**, J.M. Herrerlas**. *Servicio Central de Investigaci6n en Ciencias de la Salud de la Universidad de Cfidiz. Espaha. **Servieio de Aparato Digestive. Hospital Virgen de Macarena. Universidad de Seville. Espafia.