Fiber type composition of pubococcygeus and bulbospongiosus striated muscles is modified by multiparity in the rabbit

Abstract

Multiparity modified the fiber type composition of Pc and Bs muscles in female rabbits. We propose that the contractile force and the physiological role of both muscles during micturition are affected because of the observed changes in the relative composition of muscle fiber types.

Multiparity modifies contractile properties of pelvic muscles affecting the genesis of vaginal pressure in rabbits

“…To explain these findings, changes affecting the connective tissue and fiber type composition of each muscle should be considered. The Bsm of multiparous rabbits exhibits a striking reduction in the fast fiber content at expenses of an increase in intermediate fibers . Such a finding agrees with the reduced tetanus force of the Bsm reported herein.…”

“…Our present study extends previous findings about the impact of the reproductive experience on structure and function of the pelvic floor in rabbits . Multiparity differentially affected the contractile force developed by Bsm, Ism, and Pcm.…”

“…Moreover, denervation or injury of PFM because of labor trauma could also affect the contractile force since the temporal coordination of pelvic and perineal striated muscle activity is altered in multiparous rabbits . Such a scenario could involve a loss of neural control, a deficit in contractile force, changes in the fiber type composition of PFM, and alteration in LUT functions …”

“…In addition to these changes involving the neural component, the muscle damage induced by multiparity seems to be greater in the Pcm than in the Bsm . Moreover, multiparity modifies the fiber type composition of Bsm and Pcm . In addition to striated muscle alterations, multiparity also impairs the histological organization of the vagina .…”

n‐butylidenephthalide treatment prolongs life span and attenuates motor neuron loss in SOD1G93A mouse model of amyotrophic lateral sclerosis

“…NADH staining is usually applied to evaluate the muscle metabolic pattern. The type I fibers relying on the oxidative metabolism have the dark staining of NADH, while type II fibers relying on the glycolytic metabolism have the light staining . In ALS, the type II fibers tend to either atrophy or convert to the type I fibers.…”