[Effects of high-dose N-acetylcysteine on the lung tissues of rats exposed to silica].
OBJECTIVE
To explore the effects of high-dose N-acetylcysteine on the lung tissues of rats exposed to silica.


METHODS
Ninety-six Wistar rats were randomly divided into model group, intervention group and control group (32 rats for each group). The rats of model group and intervention group were exposed to silica by intratracheal infusion of silica dust suspension. The rats in the intervention group were orally given high dose N-acetylcysteine. In 3, 7, 14, 28 days after exposure, eight rats in each group were sacrificed, respectively and the lung samples were collected. The pathological changes of lung were evaluated by HE and Masson staining methods. The levels of TNF-alpha and IL-8 in the BALF were detected by ELISA.


RESULTS
Compared with the control group, the alveolitis and pulmonary fibrosis in the intervention group were significantly reduced. In 3, 7, 14, 28 days after exposure, the lung/body coefficients in the intervention group were 9.30 +/- 0.78, 6.29 +/- 0.74, 7.63 +/- 0.88, 6.06 +/- 1.16 respectively, which were significantly lower than those (13.84 +/- 1.61, 9.23 +/- 0.87, 11.23 +/- 1.25, 9.56 +/- 0.76, P < 0.01 ) in the model group (P < 0.01). At the different time points, the levels of TNF-alpha and IL-8 in the BALF in the intervention group were significantly higher than those in the control group (P < 0.01), but were significantly lower than those in the model group (P < 0.01).


CONCLUSIONS
The intervention with high dose N-acetylcysteine can significantly reduce the alveolitis and the TNF-alpha and IL-8 levels in the BALF, therefore, inhibit and delay the development of pulmonary fibrosis of rats exposed to silicon dioxide.
The Second Affiliated Hospital of Qingdao University Medical College, Qingdao, Shandong Province 266042, China.
Hua
H
Zhang
Chun-Ling
CL
Zhang
D000111:Acetylcysteine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D004305:Dose-Response Relationship, Drug; D004391:Dust; D016209:Interleukin-8 / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012822:Silicon Dioxide / Q000009:adverse effects*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D004391:Dust; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D012822:Silicon Dioxide; D000111:Acetylcysteine