2.2 Mice
Six-week-old male C57BL/6 mice were randomly and evenly divided into groups as indicated in specific experiments. The mice were intraperitoneally injected with PQ (50 mg/kg, Sigma-Aldrich, 36541) for one time, whereas vehicle control, SKF (10 mg/kg, MedChemExpress, HY-100001) or lysine (10 mg/kg, Sangon Biotech, A602769) was intraperitoneally injected every day for 3 days, or as indicated. The weight, daily food and water uptake of the treated mice were recorded every day. Mice were sacrificed on day 4 or as indicated, and lung lobes were removed, fixed in 4% paraformaldehyde, dehydrated, and subjected to paraffin embedding. Lung microsections (5 µm) were stained with hematoxylin & eosin (H&E) and Masson’s trichrome to visualize fibrotic lesions. Cheek blood samples were prepared and the serum was isolated by centrifugation with 2000 rpm for 5 min. The serum was monitored in Servicebio (Wuhan, China) for blood levels of calcium, ALT, AST, and creatinine. All the animal studies were approved by the Ethics Committee of Shanghai General Hospital.