Distribution and size of myofibers in quadriceps muscle of Syrian hamster.

Formalin-fixed myosin adenosine triphosphatase preparations of Syrian hamster quadriceps muscle showed myofibers distributed as follows: (1) vastus intermedius--light and dark fibers; (2) vastus medialis, rectus femoris, and vastus lateralis--light, intermediate, and dark fibers in the deep portion; and intermediate fibers with scattered dark fibers in the superficial portion. Transverse diameters varied among fibers in different portions of the quadriceps. These findings must be considered in experiments of muscle or motor endplates in hamster quadriceps muscle.