AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 2 250-R257, Copyright © 1986 by American Physiological Society

ARTICLES

Analysis of factors involved in determining urinary bladder voiding cycle in urethan-anesthetized rats

C. A. Maggi, S. Giuliani, P. Santicioli and A. Meli

The mechanism(s) involved in determining the voiding cycle of the rat urinary bladder have been investigated in urethan-anesthetized animals. Fluid emission is almost confined to that phase of the voiding cycle which is characterized by the presence of a series of high-frequency oscillations in intraluminal pressure (IPHFO). During this phase the mean urethral flow rate reached a maximum and fluid was expelled in a stream-like fashion. The index obtained by multiplying the amplitude of IPHFO by their duration was significantly related to the maximal value of urethral flow rate. The IPHFO were selectively abolished by administration of d-tubocurarine at a dose that barely affects detrusor contractility. Moreover, d-tubocurarine reduced mean urethral flow rate and increased residual volume. The reflex (hexamethonium sensitive) mechanism(s) responsible for the generation of IPHFO is more developed in male than female rats. This mechanism, which involves activation of skeletal muscle, plays a significant role in determining bladder voiding in this species.

This article has been cited by other articles:

				H.-Y. Chang and L. A. Havton Differential effects of urethane and isoflurane on external urethral sphincter electromyography and cystometry in rats Am J Physiol Renal Physiol, October 1, 2008; 295(4): F1248 - F1253. [Abstract] [Full Text] [PDF]

				M. Yoshiyama, H. Kobayashi, I. Araki, S. Du, H. Zakoji, and M. Takeda Sex-related differences in activity of lower urinary tract in response to intravesical acid irritation in decerebrate unanesthetized mice Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2008; 295(3): R954 - R960. [Abstract] [Full Text] [PDF]

				C.-W. Peng, J.-J. J. Chen, C.-L. Cheng, and W. M. Grill Role of pudendal afferents in voiding efficiency in the rat Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R660 - R672. [Abstract] [Full Text] [PDF]

				H.-Y. Chang, C.-L. Cheng, J.-J. J. Chen, and W. C. de Groat Serotonergic drugs and spinal cord transections indicate that different spinal circuits are involved in external urethral sphincter activity in rats Am J Physiol Renal Physiol, March 1, 2007; 292(3): F1044 - F1053. [Abstract] [Full Text] [PDF]

				H.-Y. Chang, C.-L. Cheng, J.-J. J. Chen, and W. C. de Groat Roles of glutamatergic and serotonergic mechanisms in reflex control of the external urethral sphincter in urethane-anesthetized female rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2006; 291(1): R224 - R234. [Abstract] [Full Text] [PDF]

				Y. Cruz and J. W. Downie Abdominal muscle activity during voiding in female rats with normal or irritated bladder Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1436 - R1445. [Abstract] [Full Text] [PDF]

				Y. Cruz and J. W. Downie Sexually dimorphic micturition in rats: relationship of perineal muscle activity to voiding pattern Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2005; 289(5): R1307 - R1318. [Abstract] [Full Text] [PDF]