(A–F) mRNA levels in skeletal muscle of control rats (C, open bars) and rats self-administering D-meth (M, closed bars): (A) p53; (B) p21; (C) p16; (D) IGF-1; (E) IL-6; (F) TNF-α. (G) Effects of D-meth self-administration (M), L-cycloserine (L-CS) treatment or a combination of D-meth and L-cycloserine (L-CS) on body weight. (H–M) mRNA levels in skeletal muscle of control rats and rats that received two 10 mg-kg-1 injections of D-meth in a 2-h period: (H) p53; (I) p21; (J) p16; (K) IGF-1; (L) IL-6; (M) TNF-α. Values are expressed as the mean±s.e.m. *P<0.05, **P<0.01, ***P<0.001, two-tailed Student’s t test. *P<0.05, **P<0.01, ***P<0.001, ANOVA followed by Bonferroni post hoc test.