Nandrolone decanoate administration and skeletal muscle regeneration

Abstract

Although testosterone is a potent regulator of skeletal muscle growth, less is understood about its ability to enhance muscle regeneration from injury. The purpose of this study was to determine if mouse tibialis anterior muscle (TA) muscle regeneration from myotoxin injury was responsive to anabolic steroid administration. Castrated male C57BL/6 mice were subjected to bupivacaine (BUP) injection with and without administration of Nandrolone decanoate (ND; 6mg/kg bw/wk). ND administration increased the incidence of small diameter fibers during the first 2 weeks of recovery from BUP by 65% when compared to BUP-only treated TA muscle, and a 280% increase above non-BUP treated mice. After 28 days of recovery, there was no difference in small diameter fibers in BUP and BUP+ND animals, but the incidence of large diameter fibers was 2-fold greater in BUP+ND muscle when compared to BUP only. These data indicate that ND administration enhances both mouse TA small fiber incidence at the onset of regeneration and myofiber growth during later phases of recovery. Supported by NIH 5R03AR051434-02