FIGURE 1.

Microcystin-RR (MC-RR) attenuates bleomycin (BLM)-induced pulmonary fibrosis. Rats received a single intratracheal instillation of 5.0 mg/kg BLM on day 0. Some of these animals were treated with MC-RR (20 μg/L) in drinking water on day 14. The control rats received saline intratracheal administration and had distilled water for daily drinking. Rats were euthanized on day 56 after BLM instillation, and lung tissue samples were collected for analysis. (A) Schematic representation of the experimental design. (B) Lung tissue sections were prepared and subjected to Masson’s trichrome and H&E staining. Scale bar: 100 μm. (C,D) Ashcroft and inflammation scores of stained sections of lung tissues were assessed by two pathologists blinded to the study design and are shown as the mean ± SD per group. (E) Lung tissue collagen contents were measured by a hydroxyproline assay. Data are expressed as mean ± SD. *p < 0.05, **p < 0.01 determined by one-way ANOVA with S-N-K post-hoc analysis. Each group had five rats.