Sex-specific reductions in body and skeletal muscle mass in nNOS-deficient mice.

<p>The body masses of 8 week old adult male (M) and female (F) mice homozygous for the wild type <i>NOS1</i> allele (+/+) or <i>NOS1</i> null allele (−/−) are shown in A. The body masses of wild type males are significantly larger (p<0.01) than KN1 littermates and wild type females (p<0.01) (A). The masses of tibialis anterior (TA) muscles from 8 week old adult wild type males are significantly larger (p<0.01) than KN1 male littermates and wild type females (B). The masses of soleus muscles are similarly affected in nNOS mutant mice where KN1 male solei are significantly smaller (p<0.05) than male littermate controls (C). The soleus muscle of wild type males is larger than that of wild type females (p<0.05). Numbers of animals analyzed: 10–11 wild type males, 11 KN1 males, 10–11 wild type females and 12–13 KN1 females. Values shown are mean±standard error of the mean (S.E.M).