Figure 2.

Skeletal muscle histology of phospholamban rabbits. (a) RNA blots from nontransgenic and an ill, transgenic rabbit at 6 months. An effort was made to obtain samples from overtly healthy tissue in order to avoid titrating RNA levels present at a site in which substantial fatty infiltrates were present. Only modest levels of overexpression in both the soleus and gastrocnemius were detected. (b) Skeletal muscle samples were collected from 6 month old rabbits. No gender differences presented. All sections were stained with Masson’s trichrome and images captured at 10X magnification. An example of an ill F0 animal is also shown. The slow-twitch skeletal muscle in which phospholamban was driven exhibited a dystrophic-like phenotype, as evidenced by the severe muscle wasting in the soleus muscle and, to a lesser extent, in the gastrocnemius, reflecting the mixed fiber-types present in that muscle. This animal had 2.2-fold overexpression of phospholamban at the RNA level in the soleus (data not shown); protein levels were not determined because of the extensive wasting that was present.