The aim of the study is to evaluate the ability of short glyprolines with arginine on C-end - PGPR, PGR and GPR – to increase gastric mucosa resistance to damaging factors, such as ethanol. The reason for the study is that glyprolines effectively support disrupted gastric mucosa homeostasis, among their other effects. PGP and PG demonstrated different combinations of protective effects on different gastric ulcer models (stress- and ethanol-induced ulcers, acetate ulcer). According to recent data, as GPR has already shown biological activity not connected with gastric mucosa homeostasis: it successfully inhibited ADP-induced platelet aggregation and prevented neuronal death caused by beta-amyloid. So it is perspective to study influence of glyprolines on C-end on gastric mucosa homeostasis. In this work we investigated their possible effect on ethanol ulcer model. Peptides were administered intragastrically in 3.7 mmol/kg dose 1 hour prior to ethanol. 5 ml/kg dose of 96% ethanol was used to induce gastric mucosa damage. PGPR and PGR showed significant decrease in size of mucosa lesions (32.4712.39% and 41.7825.53% of control size respectively). GPR was ineffective on ethanol model (93.3781.54% of control size). Glyprolines with arginine on C-end showed similar efficacy as original glyprolines: PGP and PGPR antiulcer effects are almost the same (64.0% and 67.53% respectively) and PGR was less effective than PG (58.22% compared to 83.1%).

Conclusions: 

besides already known biological activities of glyprolines with arginine on C-end, peptides PGPR and PGR demonstrate significant protective antiulcer effect on ethanol-induced ulcer and GPR is ineffective.