Effect of systemic fibrinogen depletion on muscle regeneration of Plg-deficient mice.

Plg-deficient mice were implanted 3 days before glycerol-induced muscle degeneration with ancrod-filled mini-osmotic pumps (3U/d over 13 days) (ancrod) or with buffered-filled pumps (saline). (A) Ancrod treatment reduces fibrinogen in blood of Plg-deficient mice. Forty micrograms of sodium citrate–treated blood obtained from saline- or ancrod-infused mice was analyzed in a 6% polyacrylamide gel by Western blotting using a polyclonal antimouse fibrinogen antibody (1:1000). The 340-kd approximate molecular mass species indicated by an arrow corresponds to murine fibrinogen and was calculated according to standard molecular mass markers electrophoresed in an adjacent lane. (B) Fibrinogen depletion restores muscle regeneration in Plg-deficient mice. Cryosections from saline- and ancrod-treated Plg-deficient mice were stained with H/E 10 days AI. While well-advanced regeneration is visible in ancrod-treated Plg^−/− mice, a regeneration defect is still observed in saline-treated mice 10 days after injury. Original magnification × 400.