Remote renal injury is a drastic consequence of hepatic ischemia/reperfusion (IR) injury. Vildagliptin (V) is a dipeptidyl peptidase-4 inhibitor that has a hepatorenal protective effect against models of liver and renal IR. This research was done to explore the protective role of vildagliptin against renal injury following hepatic IR injury as well as the possible involvement of transforming growth factor-beta (TGF-β)/Smad/alpha-smooth muscle actin (α-SMA) expressions in the pathophysiological mechanism of the remote renal injury. Three groups of male Wistar rats were organized into: sham group, IR group, and V + IR group in which 10 mg/kg/day of vildagliptin was pretreated for 10 days intraperitoneally. Blood in addition to renal and hepatic tissue samples was used for biochemical and histopathological studies. Hepatic IR induced a marked increase in serum creatinine, blood urea nitrogen, liver enzymes, renal nitric oxide, malondialdehyde, tumor necrosis factor-alpha levels with a marked upregulation of renal mRNA expressions of TGF-β, Smad2, Smad3, and α-SMA in addition to a marked decline in renal catalase content comparing to the sham group. Abnormal histopathological findings of hepatic and renal injury were detected in the IR group. Vildagliptin significantly improved these biochemical markers as well as the histopathological changes. The upregulation of renal TGF-β/Smad/α-SMA mRNA expressions was involved for the first time in the pathogenesis of the renal injury following hepatic IR and vildagliptin ameliorated this renal injury through blocking these expressions.
Keywords: Hepatic ischemia/reperfusion; TGF-β; renal injury; vildagliptin; α-SMA.