THE ROLE OF PUBOCOCCYGEUS MUSCLE - IN URINARY CONTINENCE IN THE MALE-RAT

The role of the male rat pubococcygeus muscle (Pcm) in the micturition reflex was analyzed. Anatomical features of Pcm, electrical stimulati on of its nerve, electrical recording and stimulation of the muscle an d cystometrograms were carried out. Results showed that Pcm has fibers attached to the ventrolateral part of the external urethral sphincter , and that its activity contributes to hold the tail in the midline. P cm shows activity during fluid expulsion in cystometrograms and sponta neous micturitions. This activity produced reflex inhibition of detrus or contraction and was not the cause of intravesical high frequency os cillations. Thus, it is proposed that Pcm activity produces the discha rge of its afferents which in turn activates a spinal reflex to promot e continence.