Skip to main content

Mechanisms of reflex bladder activation by pudendal afferents.

Publication ,  Journal Article
Woock, JP; Yoo, PB; Grill, WM
Published in: American journal of physiology. Regulatory, integrative and comparative physiology
February 2011

Activation of pudendal afferents can evoke bladder contraction or relaxation dependent on the frequency of stimulation, but the mechanisms of reflex bladder excitation evoked by pudendal afferent stimulation are unknown. The objective of this study was to determine the contributions of sympathetic and parasympathetic mechanisms to bladder contractions evoked by stimulation of the dorsal nerve of the penis (DNP) in α-chloralose anesthetized adult male cats. Bladder contractions were evoked by DNP stimulation only above a bladder volume threshold equal to 73 ± 12% of the distension-evoked reflex contraction volume threshold. Bilateral hypogastric nerve transection (to eliminate sympathetic innervation of the bladder) or administration of propranolol (a β-adrenergic antagonist) decreased the stimulation-evoked and distension-evoked volume thresholds by -25% to -39%. Neither hypogastric nerve transection nor propranolol affected contraction magnitude, and robust bladder contractions were still evoked by stimulation at volume thresholds below the distension-evoked volume threshold. As well, inhibition of distention-evoked reflex bladder contractions by 10 Hz stimulation of the DNP was preserved following bilateral hypogastric nerve transection. Administration of phentolamine (an α-adrenergic antagonist) increased stimulation-evoked and distension-evoked volume thresholds by 18%, but again, robust contractions were still evoked by stimulation at volumes below the distension-evoked threshold. These results indicate that sympathetic mechanisms contribute to establishing the volume dependence of reflex contractions but are not critical to the excitatory pudendal to bladder reflex. A strong correlation between the magnitude of stimulation-evoked bladder contractions and bladder volume supports that convergence of pelvic afferents and pudendal afferents is responsible for bladder excitation evoked by pudendal afferents. Further, abolition of stimulation-evoked bladder contractions following administration of hexamethonium bromide confirmed that contractions were generated by pelvic efferent activation via the pelvic ganglion. These findings indicate that pudendal afferent stimulation evokes bladder contractions through convergence with pelvic afferents to increase pelvic efferent activity.

Duke Scholars

Published In

American journal of physiology. Regulatory, integrative and comparative physiology

DOI

EISSN

1522-1490

ISSN

0363-6119

Publication Date

February 2011

Volume

300

Issue

2

Start / End Page

R398 / R407

Related Subject Headings

  • Urinary Bladder
  • Sympathetic Nervous System
  • Spinal Cord Injuries
  • Reflex
  • Pressure
  • Physiology
  • Penis
  • Muscle, Smooth
  • Muscle Contraction
  • Male
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Woock, J. P., Yoo, P. B., & Grill, W. M. (2011). Mechanisms of reflex bladder activation by pudendal afferents. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 300(2), R398–R407. https://doi.org/10.1152/ajpregu.00154.2010
Woock, John P., Paul B. Yoo, and Warren M. Grill. “Mechanisms of reflex bladder activation by pudendal afferents.American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 300, no. 2 (February 2011): R398–407. https://doi.org/10.1152/ajpregu.00154.2010.
Woock JP, Yoo PB, Grill WM. Mechanisms of reflex bladder activation by pudendal afferents. American journal of physiology Regulatory, integrative and comparative physiology. 2011 Feb;300(2):R398–407.
Woock, John P., et al. “Mechanisms of reflex bladder activation by pudendal afferents.American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, vol. 300, no. 2, Feb. 2011, pp. R398–407. Epmc, doi:10.1152/ajpregu.00154.2010.
Woock JP, Yoo PB, Grill WM. Mechanisms of reflex bladder activation by pudendal afferents. American journal of physiology Regulatory, integrative and comparative physiology. 2011 Feb;300(2):R398–R407.

Published In

American journal of physiology. Regulatory, integrative and comparative physiology

DOI

EISSN

1522-1490

ISSN

0363-6119

Publication Date

February 2011

Volume

300

Issue

2

Start / End Page

R398 / R407

Related Subject Headings

  • Urinary Bladder
  • Sympathetic Nervous System
  • Spinal Cord Injuries
  • Reflex
  • Pressure
  • Physiology
  • Penis
  • Muscle, Smooth
  • Muscle Contraction
  • Male