title: Evidence that mesothelial cells regulate the acute inflammatory response in talc pleurodesis.
abstract: Intrapleural instillation of talc is used to produce pleurodesis in cases of recurrent malignant pleural effusions. The mechanisms by which pleurodesis is produced remain unknown but may involve either injury or activation of the mesothelium. The aim of the current study was to assess the inflammatory response of pleural mesothelial cells to talc in an experimental model in rabbits. A group of 10 rabbits were injected intrapleurally with talc (200 mg.kg(-1)) and undiluted pleural fluid was collected after 6, 24 or 48 h for measurement of interleukin (IL)-8, vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta1. Samples of pleura were studied to assess the inflammatory infiltrate and mesothelial cell viability. The pleural fluid IL-8 concentration peaked at 6 h, whereas VEGF and TGF-beta1 concentrations increased steadily over 48 h. Immunohistochemistry for cytokeratin showed a preserved layer of mesothelial cells despite the intense inflammatory pleural reaction. In conclusion, it is proposed that the mesothelial cell, although injured by the talc, may actively mediate the primary inflammatory pleural response in talc-induced pleurodesis.
authors.affiliation: Pleura Laboratory - Pulmonary Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. evmarchi@uol.com.br
authors.forename: E
authors.initials: E
authors.lastname: Marchi
authors.forename: F S
authors.initials: FS
authors.lastname: Vargas
authors.forename: M M
authors.initials: MM
authors.lastname: Acencio
authors.forename: L
authors.initials: L
authors.lastname: Antonangelo
authors.forename: E H
authors.initials: EH
authors.lastname: Genofre
authors.forename: L R
authors.initials: LR
authors.lastname: Teixeira
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology*; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D010996:Pleural Effusion / Q000276:immunology*; D018700:Pleurodesis; D011817:Rabbits; D013627:Talc / Q000276:immunology / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000187:drug effects / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects / Q000378:metabolism
chemical_list: D016209:Interleukin-8; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D013627:Talc