Paraquat-Induced Lung Injury and Klotho Treatment

PQ dichloride (Sigma-Aldrich, USA) was dissolved in distilled water. For PQ treatment, the mice were IP administered PQ at a single dose of 30 mg/kg. The PQ dosage was selected according to former studies [16 (link), 17 (link)] and our preliminary experiments. An identical volume of normal saline was applied IP as control. For KL administration, the recombinant mouse KL protein (R&D Systems, USA; 10 μg/kg) dissolved in phosphate-buffered saline (PBS, 0.01 mM) was injected IP 6 h prior to PQ treatment followed by every other day injection for 7 days. The dosage of KL was selected based on previous studies [18 (link)]. The mice were randomly assigned to four groups of 12 and studied concomitantly. The grouping design is as follows: control group (mice receiving IP injection of PBS), KL group (mice receiving IP injection of KL), PQ group (mice receiving PQ treatment), and KL+PQ group (mice receiving IP injection of KL 6 h before PQ treatment). The mice were sacrificed concurrently 7 days after PQ administration.