OBJECTIVE: Acute kidney injury (AKI) is a common and important clinical challenge, and renal ischemia/ reperfusion (I/R) injury is the major reason of AKI. Renal I/R can lead to lung injury, which is associated with increased mortality. This study was designed to evaluate whether paricalcitol may protect against lung injury following renal I/R injury via its antioxidant properties. STUDY DESIGN: Rats (n=7 per group) were divided into 4 groups: control, paricalcitol, I/R, and paricalcitol+ I/R. Rats received daily intraperitoneal injection of paricalcitol (0.3 μg/kg) for 5 days in the paricalcitol and paricalcitol+I/R groups. On day 6, rats were subjected to I/R injury (60 minutes of left renal artery occlusion followed by 60 minutes of reperfusion) after right nephrectomy. Renal function tests, oxidant and antioxidant parameters, and lung histology of both groups were examined. RESULTS: Pretreatment of rats with paricalcitol in the paricalcitol+I/R group significantly decreased serum urea and creatinine levels as compared with the I/R group (p<0.05). Malondialdehyde (MDA) and total oxidant status (TOS) levels were significantly increased in serum and lung tissue of the I/R group as compared with the control and paricalcitol groups (p<0.05). Rats treated with paricalcitol prior to I/R injury exhibited significant reduction in terms of serum and lung tissue TOS and MDA levels and significant increase in terms of serum and lung tissue nitric oxide and total antioxidant capacity levels (p<0.05). The lung histopathological scores were significantly higher in the I/R group as compared with the paricalcitol+I/R group (p<0.05). CONCLUSION: Paricalcitol may ameliorate renal I/Rinduced lung injury by attenuating oxidative stress. © Science Printers and Publishers, Inc.