The rats were exposed to the nanomaterial suspension by intratracheal instillation once every 2 days for 5 weeks. The group of corn oil-instilled rats served as controls. After removal from the inhalation anesthetic, the rats recovered and were active within 10 min. The rats were divided into seven groups randomly by weight, including low-and high-dose groups of the three AR-13324 in vitro nanomaterials, and a control group. Histopathological evaluation The middle of the left lungs was embedded in paraffin and thin-sectioned coronally; then, sections

were stained with hematoxylin-eosin and examined by light microscopy. Preparation of BALF and detection Twenty-four hours after the last instillation, rats were anesthetized with ether, bled from the femoral artery and sacrificed by cervical decapitation. The lung and trachea were exposed by dissection, and then the left lung was temporarily clamped. The right lung was lavaged with 6 mL of warm normal saline; then, the recovered BALF were centrifuged at 400 × g for 10 min. The concentrations of lactate dehydrogenase (LDH), total antioxidant

capacity (T-AOC), superoxide dismutase (SOD), and malondialdehyde selleck chemicals (MDA) in BALF were analyzed using biochemical analysis kits (Shangbo, Beijing, China). The reactions were selleckchem measured using a UV/Vis spectrometer (UNICAM UV2, ATI-Unicam, Cambridge, UK). The levels of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis

factor alpha (TNF-α) in lung homogenates were analyzed using enzyme-linked immunosorbent assay (ELISA) kits (Shangbo). The reactions were measured using an ELISA reader. Comparative proteomics analysis The left lungs of rats were excised, immediately cooled in ice, and homogenized in a Teflon-glass homogenizer. Then, the homogenates were centrifuged at 700 × g for 15 min. Homogenized lung tissue of 40 to 100 mg was placed in 2 mL of lysis buffer containing 8 mol · L−1 urea, 4% CHAPS, 40 mmol · L−1 Buspirone HCl Tris, 65 mmol · L−1 DDT, and 1 mmol · L−1 PMSF and then centrifuged for 20 min at 12,000 rpm after being kept for 1 h at room temperature. Samples were stored in aliquots at −80°C. Protein determination was carried out according to the Bradford assay. Two-dimensional electrophoresis First-dimension isoelectric focusing on immobilized pH gradient One milligram of protein sample, 7 μL of DTT (1 mol · L−1), and 1.75 μL of IPG buffer (20 mmol · L−1) were solubilized in 350 μL of rehydration solution containing 8 mol · L−1 urea, 2% CHAPS, and a trace of bromophenol blue. This solution was pipetted into each 18-cm pH 3-10 strip holder. The strip holder was positioned on the IPGphor™ 3 isoelectric focusing system (Amersham Pharmacia, Little Chalfont, UK). Rehydration and isoelectric focusing (IEF) were carried out at 20°C.