Figure 2. Relationship between running activity and LW/BW ratio and histological lung sections stained with Berlin blue.

A . Running activity of WT and DCM mice at 2 (left) and 3 months of age (right). Bars are mean±SD. B . Relationship between running activity and LW/HW ratio in mice at approximately 3 months of age and average running activities in WT, DCM with high (>5 km/day, denoted “HI”) and low (<1 km/day, denoted “LO”) running activities (Left). Note that DCM mice (filled circles) with running activity of >5 km/day (HI) and all WT mice (open circles) showed similar LW/BW ratios, approximately 0.6% on average, whereas LW/BW ratios in all DCM mice with running activity of <1 km/day (LO) showed LW/BW ratios of >1%. C . Representative images of Berlin blue-stained lung sections from WT and HI and LO groups of DCM mice. Berlin blue-positive macrophages are detected only in sections from DCM mice with low activity. Bar indicates 100 µm. Inset: enlarged image. D. Average numbers of Berlin blue-positive alveolar macrophages per field of view of 0.2×0.25 mm². Error bars are mean±SD (n = 4–5).