Figure 3.

Extraocular lateral rectus muscle sections: (A–D) control; (E–H) hyperthyroid rabbits immunostained for the presence of (A, E) fast, (B, F) slow, (C, G) developmental, and (D, H) neonatal MyHC isoforms. Positive myofibers appear black. Note that the global layer is to the left in all images and a portion of the orbital layer can be seen at right. These sections are intermediate between the midbelly and tendon ends. Note the decrease in myofibers positive for developmental and neonatal MyHC isoforms in the muscles from the hyperthyroid rabbit. Bar, 20 μm.