Temporal coordination of pelvic and perineal striated muscle activity during micturition in female rabbits.
OBJECTIVE
To determine the motor basis of urine expulsion the activity of the pelvic (pubococcygeus) and perineal (bulbospongiosus and ischiocavernosus) muscles was recorded during micturition in anesthetized female rabbits.


METHODS
Virgin female chinchilla rabbits were used for simultaneously recording cystometrograms and electromyograms of the pubococcygeus, ischiocavernosus and bulbospongiosus muscles. The particular contribution of each muscle during micturition was analyzed in another set of experiments in which each was inactivated by bilateral lidocaine injection. Bladder function was assessed using standard urodynamic parameters.


RESULTS
Cystometrography showed that micturition comprises 2 phases, that is storage and voiding phases. During the latter phase no high frequency oscillations were recorded. On simultaneous electromyography recordings a temporal, coordinated activation of pelvic (pubococcygeus) and perineal (bulbospongiosus and ischiocavernosus) muscles was observed. During specific blockade of each muscle some modifications in urodynamic parameters were found.


CONCLUSIONS
Our findings indicate a specific role for the pelvic and perineal muscles during feminine micturition.
Corona-Quintanilla
Dora Luz
DL
Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
Castelán
Francisco
F
Fajardo
Victor
V
Manzo
Jorge
J
Martínez-Gómez
Margarita
M
D000818:Animals; D005260:Female; D054792:Muscle, Striated / Q000502:physiology*; D017773:Pelvic Floor / Q000502:physiology*; D010502:Perineum / Q000502:physiology*; D011817:Rabbits; D013997:Time Factors; D014554:Urination / Q000502:physiology*