LAUSR

Graphical abstract Figure. No caption available. Background and purpose: Besides hydrogen sulfide (H2S) and nitric oxide (NO), carbon monoxide (CO) contributes to the maintenance of gastric mucosal integrity. We investigated increased CO bioavailability effects on time‐dependent dynamics of gastric ulcer healing mediated by particular growth factors, anti‐inflammatory and molecular pathways. Experimental approach: Wistar rats with gastric ulcers induced by serosal acetic acid application (day 0) were treated i.g. throughout 3, 6 or 14 days with vehicle or CO‐releasing tricarbonyldichlororuthenium (II) dimer (CORM‐2, 2.5 mg/kg). Gross and microscopic alterations in gastric ulcer size and gastric blood flow (GBF) at ulcer margin were determined by planimetry, histology and laser flowmetry, respectively. Gastric mRNA/protein expressions of platelet derived growth factors (PDGFA‐D), insulin‐like growth factor (IGF‐1), epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGFA) and their receptors, heme oxygenases (HMOX), nuclear factor (erythroid‐derived 2)‐like 2 (Nrf‐2), cyclooxygenase (COX‐2), hypoxia inducible factor (HIF)‐1&agr;, anti‐inflammatory annexin‐1 and transforming growth factor (TGF‐&bgr;1) were assessed by real‐time PCR or Western blot. TGF‐&bgr;1‐3 and IL‐10 plasma concentration were measured using Luminex platform. Prostaglandin E2 content at ulcer margin was assessed by ELISA. Key results: CORM‐2 decreased ulcer area and increased GBF after 6 and 14 days of treatment comparing to vehicle. CO donor upregulated HGF, HGFr, VEGFR1, VEGFR2, TGF‐&bgr;1, annexin‐1 and maintained increased IGF‐1, PDGFC and EGF expression at various time‐intervals of ulcer healing. TGF‐&bgr;3 and IL‐10 plasma concentration were significantly increased after COMR‐2 vs. vehicle. Conclusions: CO time‐dependently accelerates gastric ulcer healing and raises GBF at ulcer margin by mechanism involving subsequent upregulation of anti‐inflammatory, growth promoting and angiogenic factors response, not observed physiologically.