Quantification of Ki67 Staining in Rat Pulmonary Arteries.

<p>Immunohistochemistry for Ki67 was performed on rat lung sections from animals injured with MCT treated with or without fumagillin. Images of pulmonary arteries are shown (A) uninjured + vehicle (B) uninjured + fumagillin (C) MCT + vehicle and (D) MCT + fumagillin (Magnification ×400, bar = 20 µm). Black arrows point to Ki67+ nuclei in the medial layer of pulmonary arteries and yellow arrows point to Ki67+ nuclei in endothelial cells. Magnification ×400, inset line 20 mm. (E) Ki67+ nuclei in the medial layer (n = 4–6 per group) and (F) Ki67+ nuclei in endothelial cells of the pulmonary arteries (n = 4 per group) were quantified per hpf as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035388#s2" target="_blank">Materials and Methods</a>. MCT injury resulted in a nearly 15-fold increase in the number of Ki67+ nuclei in medial cells per vessel per hpf in the MCT-injured vehicle-treated lung. The increase in the number of Ki67+ nuclei was decreased nearly 30% with fumagillin treatment, but this difference did not reach statistical significance. Similarly, MCT significantly increased the number of endothelial cells staining positively for Ki67 nearly tenfold. However, no differences in the number of Ki67+ nuclei were detected after fumagillin treatment.