Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion

Background This study evaluated the protective effect of sildenafil on liver injury induced by intestinal ischemia-reperfusion. Methods Forty female Sprague Dawley rats were divided into 4 groups: sham-control (SC), ischemia (I), ischemia-reperfusion (IR), and ischemia-reperfusion + sildenafil (SIL; sildenafil gavaged at 50 mg/kg before operating). A 2-h ischemia-reperfusion was performed by clamping the superior mesenteric artery. Liver function, plasma alanine (ALT) and aspartate (AST) aminotransferase, and intestinal and liver malondialdehyde (MDA) were measured at the end of the experiment. Intestinal and liver tissue damage was examined by histology. Liver samples were immunologically stained for endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA). Results The ALT and AST levels were highest in the IR group and were lower in the SIL group (p < 0.05). Intestinal MDA levels were statistically higher in the IR group than in the SC, I and SIL groups. Liver MDA levels were significantly higher in the IR group than in the I and SC groups (p < 0.05) and higher than in the SIL group (p > 0.05). Intestinal damage based on Chiu scoring was more severe in the IR than in the SIL group (p < 0.05). Sildenafil reduced damage and also increased eNOS and PCNA immunoreactivity in liver tissue. Conclusions Sildenafil shows a protective effect on intestinal ischemia-reperfusion-induced liver injury, possibly by decreasing vascular resistance through increased nitric oxide levels. © 2013 Elsevier Inc.