title: Methylprednisolone effects on oxygenation and histology in a rat model of acute lung injury.
abstract: We examined the effects of methylprednisolone on gas exchange, pressure-volume curve, lavage fluid inflammatory cell counts, protein content, surfactant pool size, and lung histology in a rat model of paraquat-induced lung injury. Twenty-three adult male Sprague-Dawley rats received intraperitoneal paraquat injection (35 mg/kg) and were randomly divided into three groups: (1). control group received no further treatment; (2). 1-dose methylprednisolone group received a concomitant intraperitoneal methylprednisolone injection (30 mg/kg); (3). 3-dose methylprednisolone group received a concomitant and daily intraperitoneal methylprednisolone injection (30 mg/kg) for three doses. Three days after paraquat injection, the rat was ventilated for 90 min, a static pressure-volume curve and bronchoalveolar lavage was performed, and postmortem histology was examined. Surfactant pool size of the 3-dose methylprednisolone group was significantly increased when compared with the control and 1-dose methylprednisolone groups. Methylprednisolone treatment increased oxygenation and the value was statistically significant for 3-dose methylprednisolone group at 90 min of ventilation. Inflammatory cell counts in bronchoalveolar lavage fluid and lung injury score were decreased as the methylprednisolone dose increased. We conclude that high-dose methylprednisolone treatment increased surfactant pool size and improved lung histology of paraquat-injured lungs but this augmentation could not significantly improve oxygenation throughout the ventilation period.
authors.affiliation: Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan, ROC.
authors.forename: Chung-Ming
authors.initials: CM
authors.lastname: Chen
authors.forename: Leng-Fang
authors.initials: LF
authors.lastname: Wang
authors.forename: Borcherng
authors.initials: B
authors.lastname: Su
authors.forename: Hsun-Hui
authors.initials: HH
authors.lastname: Hsu
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005938:Glucocorticoids / Q000627:therapeutic use*; D006540:Herbicides / Q000633:toxicity; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D010269:Paraquat / Q000633:toxicity; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology
chemical_list: D005938:Glucocorticoids; D006540:Herbicides; D010269:Paraquat; D008775:Methylprednisolone