Figure 1.

Exposure to arsenic does not render the muscle more susceptible to injury, but results in a decreased regeneration and disrupted matrix deposition 10 days after injury. (A): The average number of Evans blue positive myofibers/cross-section in control and arsenic-exposed muscle after 1 day following cardiotoxin injection. (B): Average number of myofibers/cross-sectional area 10 days after cardiotoxin injection. (C): Evans blue auto-fluorescence in control and arsenic-exposed myofibers (red = Evans blue, blue = DAPI). n = 4 per group, p > 0.05 according to a two-tailed Student’s t-test. Scale bar 5 100 µm. (D): Laminin α2 staining in control and arsenic-exposed muscles (green 5 Laminin α2, blue = DAPI). n = 4 per group, **, p < 0.01, according to a two-tailed Student’s t-test. Scale bar 5 50 µm. (E):Second harmonics generation imaging of muscles exposed to 0 or 100 µg/LAs(III) for 5 weeks reveals an impaired myo-fiber regeneration and disrupted matrix remodeling with exposure to As(III)(Collagen fibers in red; myofibers in green). Ten days after injury, As(III)-exposed muscles demonstrate an increased collagen fibril alignment, as calculated by the orientation index (OI). (F): Schematic representation of OI. (G): OI of control and As (III) exposed muscles. (n = 3 in control and n = 4 in As (III) group, *, p < 0.05, 11– 13 stacked images/sample, right panel). Abbreviations: EBD, Evans blue dye; OI, orientation index.