2.10. Enzyme-Linked Immunosorbent Assay (ELISA) for Measuring Inflammatory Cytokines

ELISA was performed to measure the content of TNF-α, IL-6, and IL-1β in lung tissues. Wet lung tissue (100 mg) was homogenized, centrifuged at 4°C (12,000 rpm for 15 min), and the supernatant was collected. The inflammatory cytokine content was examined according to the manufacturer's protocol. The ELISA kits were purchased from IBL International GmbH (Hamburg, Germany). The optical density was determined at 450 nm on a spectrophotometer (Molecular Devices Corporation, Sunnyvale, CA, USA).