Abstract:

BACKGROUND: Electromyography characteristic and constitution percentage of enzyme histochemistry of intrafusal fibers and extrafusal fibers were interrelated with function during postnatal development of rabbit muscle. However, systematic studies addressing muscle subvolume of tibial muscle are insufficient.
OBJECTIVE: To inquire into the evoked potential and enzyme histochemistry of tibial muscle subvolume in dometic rabbits with different ages.
METHODS: General dissection combined with enzyme histochemistry was applied to explicit tibial muscle subvolume in dometic rabbits with different ages; at the same time, the function of muscle subvolume was surveyed using electric physiology record instrument. The inducing potential amplitude, continued time and wave motion, extrafusal ⅡB, ⅡA, ⅡX, Ⅰ fiber composition were stained by ATPase histochemistry and the feature of intrafusal fibers were observed.
RESULTS AND CONCLUSION: The inducing potential amplitude, continued time and wave motion were smaller, the spectrum was simple and wave motion was gentle at childhood. With age increased, the inducing potential amplitude, continued time and wave motion at adult were bigger, and the spectrum was longer and complicated than the continued time of childhood. Small spinal wave appeared. Extrafusal ⅡB, ⅡA fiber of stained ATPase at anterior and posterior subvolume of tibial muscle were increased with age increasing. But the extrafusal ⅡX, Ⅰ fiber of stained ATPase at anterior and posterior subvolume of tibial muscle were decreased from postnatal ages. Intrafusal fibers were divided into nuclear bag1, nuclear bag2 and nuclear chain fibers. They were wrapped with intracapsular and extracapsular regions composed of connective tissues. Posterior subvolume maintains hind legs’ pose and joint of posterior limb with stability during standing and walking. Anterior and posterior subvolume were supplied together sufficient contractive speed and power for need of movement when the motion were needed strength and velocity.