High-fat diet induces pulmonary fibrosis in rats and inhibitory effects of N-acetylcysteine

Abstract

To explore the relation between high-fat diet and pulmonary fibrosis and the inhibition of N-acetylcysteine (NAC) on lung tissue in rats. Thirty Sprague Dawley (SD) male rats were randomly divided into control group (n = 10) on a quantitative control Lieber-DeCarli liquid diet, a high-fat diet group (n = 10) on a high fat-diet Lieber-DeCarli liquid diet and NAC group (n = 10) on NAC 300 mg×kg(-1)×d(-1). All rats were sacrificed 8 weeks later. The morphological changes and collagen deposition in lung tissue were observed by hematoxylin & eosin and Masson staining while the contents of glutathione (GSH) and hyaluronic acid (HA) measured through colorimetry and enzyme-linked immunosorbent assay. And the expression of transforming growth factor-β1 (TGF-β1) expression in lung tissue was detected through immunohistochemistry. There were variable degree of alveolar and alveolar septal infiltration of inflammatory cells. And more deposition of collagen fibers appeared at intervals of alveolar in high fat group. Similar pathological changes were found in NAC group, but the degree was lower than that of high-fat group. Compared to the control and NAC groups, the lung tissue content of GSH decreased (GSH: 0.11 ± 0.05 vs 0.19 ± 0.11, 0.22 ± 0.14 mg/g, both P < 0.05) while HA and TGF-β1 increased in high-fat diet group (HA: 0.57 ± 0.06 vs 0.46 ± 0.04, 0.41 ± 0.04 mg/g; TGF-β1: 24.6 ± 3.4 vs 16.8 ± 2.6, 11.7 ± 1.5, all P < 0.05). High-fat diet may induce pulmonary fibrosis in rats and NAC has inhibitory effects.