Angiotensin-Converting Enzyme Inhibitor Captopril: Does it Improve Renal Function in Lipopolysaccharide-induced Inflammation Model in Rats

Renin-angiotensin system as an important regulator of renal function has also a major role in inflammation. In the present study, the effects of captopril on renal dysfunction, renal cytokine levels, and renal tissue oxidative damage were investigated in lipopolysaccharide (LPS)-induced inflammation model in rats. Treatment of five groups of the rats was carried out as follows: (1) saline as a control, (2) LPS 1 mg/kg, and (3-5) 10, 50, or 100 mg/kg captopril 30 min, respectively, before LPS. The treatments were given for 12 days. Finally, the animals were deeply anesthetized, the blood samples were obtained, and the renal tissues were removed and kept for biochemical measurements. Administration of LPS increased serum blood urea nitrogen and creatinine (P < 0.001). Pretreatment with all doses of captopril decreased these parameters (P < 0.001). LPS also increased interleukin-6 (IL-6), malondialdehyde, and nitric oxide metabolites in the renal tissues (P<0.05 - P < 0.001), which was prevented by captopril (P < 0.05 - P < 0.001). The total thiol concentration and superoxide dismutase and catalase activities in the kidney of the LPS group were lower than the control (P < 0.001), while they were enhanced when the animals were cotreated by captopril (P <0.01 - P < 0.001). The results of the present study showed that captopril improved renal function and attenuated tissue oxidative stress in LPS-induced inflammation model in rats.