RESPONSE OF BLADDER, URETHRAL AND INTRACAVERNOUS PRESSURE TO VENTRAL LUMBOSACRAL ROOT STIMULATION IN SPRAGUE-DAWLEY AND WISTAR RATS

Six Sprague-Dawley and six Wistar rats were used for electrostimulation of the L5 to S2 ventral roots. Landmarks for identification of the roots were developed; bladder, urethral and intracavernous pressures were recorded; and tail and leg movements were checked. Urethral sphincter contraction was elicited by stimulation of the L5-L6 ventral roots, while bladder contraction and penile erection were mediated by the L6-S1 ventral roots. The best sphincteric response and intracavernous pressure rise were obtained by stimulation of the L6 ventral root, and the highest bladder pressures by stimulation of the S1 ventral root. Stimulation of the S1-S2 ventral roots provoked ipsilateral tail movement; of L6, tail movement, hindleg muscle twitch, and slight toe spread; and of L5, hindleg stretch and plantar flexion. No significant differences were found between the two strains of rats, although a higher bladder pressure was recorded during stimulation of the L6 ventral root in Sprague-Dawley rats, which might be explained by a small caudal shift of the sacral parasympathetic nucleus in the Wistar strain.