Effect of Long-Term Inhalation of Toner on Extracellular Matrix in the Lungs of Rats In Vivo

Autor:	Isamu Tanaka, Toshiaki Higashi, Takako Oyabu, Takahiko Kasai, Masami Hirohashi, Heungnam Kim, Akira Ogami, Hiroko Nagatomo, Yasuo Morimoto, Hiroshi Yamato
Rok vydání:	2005
Předmět:	medicine.medical_specialty Pathology Pulmonary Fibrosis Health Toxicology and Mutagenesis Matrix metalloproteinase Toxicology Collagen Type I Extracellular matrix In vivo Internal medicine Administration Inhalation Pulmonary fibrosis Gene expression medicine Animals RNA Messenger Rats Wistar Toxicity Tests Chronic Lung Tissue Inhibitor of Metalloproteinase-2 Inhalation Reverse Transcriptase Polymerase Chain Reaction Chemistry medicine.disease Extracellular Matrix Rats Trachea medicine.anatomical_structure Endocrinology Gene Expression Regulation Microscopy Electron Scanning Matrix Metalloproteinase 2 Printing Female Ink Type I collagen
Zdroj:	Inhalation Toxicology. 17:153-159
ISSN:	1091-7691 0895-8378
DOI:	10.1080/08958370590904517
Popis:	We assessed the effects of long-term inhalation of toner on the pathological changes and gene expression with the synthesis and degradation of collagenous extracellular matrix in a rat model. Female Wistar rats (10 wk old) were divided evenly into a high concentration exposure group (H: 15.2 mg/m3), a low concentration exposure group (L: 5.5 mg/m3), and a control group. The mass median aerodynamic diameter of toner was 4.5 microm. The rats were sacrificed at the termination of a 1-yr or 2-yr inhalation period. Pathological examination was performed from the left lung, and transcriptional levels of mRNA extracted from the right lung were assessed by semiquantitative reverse-transcription polymerase chain polymerase (RT-PCR). The pathological findings showed mild pulmonary fibrosis in 20% (L, 1 yr), 40% (H, 1 yr), 56% (L, 2 yr) and 62% (H, 2 yr), while lung cancer was not observed in any of the exposed groups. In the 1-yr high-concentration group, gene expression of matrix metalloproteinase-2 (MMP-2) and type I collagen mRNA in the rat lungs increased, while tissue inhibitors of metalloproteinase-2 (TIMP-2) decreased. The 2-yr high-concentration group increased in message level of type I collagen and TIMP-2 but not that of MMP-2. These data suggested that results of gene expression of MMP, TIMP, and collagen in the 2-yr exposure may lead to accumulation of collagen compared to the 1-yr exposure, and that the imbalance of the expression of MMPs, TIMPs, and extracellular matrix might be associated with pulmonary fibrosis induced by toner.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bac98dfed9454cb2d7d33cb48c2c4c41 https://doi.org/10.1080/08958370590904517 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
Nepřihlášeným uživatelům se plný text nezobrazuje	K zobrazení výsledku je třeba se přihlásit.