title: Phospholipid concentration in lung lavage fluid as biomarker for pulmonary fibrosis.
abstract: Pulmonary surfactant comprised primarily of phospholipids is a phospholipid-protein complex synthesized by type II alveolar epithelial cells or Clara cells and secreted to the pulmonary alveoli. As changes have been found in phospholipid concentrations in the bronchoalveolar lavage fluid (BALF) of patients with pulmonary fibrosis, phospholipid is considered to be involved in the process of fibrois/fibrotic process. Therefore, we made a crystalline silica rat model and measured phospholipid concentrations in lung lavage fluid in order to study the relationship of phospholipid to particle-induced pulmonary fibrosis. Eight-week-old Wistar male rats (n = 35) were injected with 2 mg crystalline silica particles suspended in 0.4 ml physiological saline. Rats in the control group (n = 35) were injected with physiological saline only. There were 7 rats in each of the ten subgroups. Rats were sacrificed and dissected at 3 days, 1 wk, 1 mo, 3 mo, and 6 mo after injection. Bronchoalveolar lavage was conducted on bronchoalveoli recovered from the right lung of each rat, the lavage fluid was centrifuged, and the supernatant was used to measure phospholipid concentration. The results were compared with previously reported inflammation scores. Phospholipid concentrations in lung lavage fluid for the exposed group showed a statistically significant increase compared to the control group throughout the observation period. Moreover, when compared to histopathologically examined inflammation scores, a positive correlation was found between the two. Judging from the facts that phospholipid concentrations in lung lavage fluid increased and that this increase correlated with the severity of inflammation, this experiment indicated that phospholipids are involved in particle-induced lung disorders.
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Kuroda
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Akira
authors.initials: A
authors.lastname: Ogami
authors.forename: Takako
authors.initials: T
authors.lastname: Oyabu
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nagatomo
authors.forename: Masami
authors.initials: M
authors.lastname: Hirohashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamato
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nagafuchi
authors.forename: Isamu
authors.initials: I
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D015415:Biomarkers; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D008168:Lung / Q000473:pathology; D008297:Male; D010743:Phospholipids / Q000032:analysis*; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D011663:Pulmonary Surfactants / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D015415:Biomarkers; D010743:Phospholipids; D011663:Pulmonary Surfactants