The Dual Function of Capsaicin-Sensitive Sensory Nerves in the Bladder and Urethra

  1. Greg Bock Organizer and
  2. Julie Whelan
  1. Carlo Alberto Maggi

Published Online: 28 SEP 2007

DOI: 10.1002/9780470513941.ch5

Ciba Foundation Symposium 151 - Neurobiology of Incontinence

Ciba Foundation Symposium 151 - Neurobiology of Incontinence

How to Cite

Maggi, C. A. (2007) The Dual Function of Capsaicin-Sensitive Sensory Nerves in the Bladder and Urethra, in Ciba Foundation Symposium 151 - Neurobiology of Incontinence (eds G. Bock and J. Whelan), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470513941.ch5

Author Information

  1. Department of Pharmacology, Division of Smooth Muscle, A Menarini Pharmaceutical Research Laboratories, Via Sette Santi 3, I-50131 Florence, Italy

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471926870

Online ISBN: 9780470513941

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Keywords:

  • capsaicin-sensitive sensory nerves;
  • urethra;
  • tachykinins;
  • cardiovascular reflexes;
  • neurobiology

Summary

The sensory innervation of the urinary bladder and urethra plays a key role in a variety of reflexes involved in urine storage and voiding. Dysfunction of these systems is a possible cause of many disturbances related to urine continence but basic knowledge in this field has been hampered by the lack of tools for studying sensory nerves. The use of capsaicin, the pungent ingredient of red peppers, allowed us to investigate the anatomical and functional properties of a specific subset of sensory neurons in the lower urinary tract. These ‘capsaicin-sensitive’ neurons play a dual sensory and ‘efferent’ function, determined by transmitter release from their central and peripheral nerve endings. Tachykinins, including substance P, and other neuropeptides such as calcitonin gene-related peptide, mediate the functions of these sensory neurons. The ‘sensory’ function includes regulation of micturition threshold, activation of cardiovascular reflexes and perception of pain from the urinary bladder. The ‘efferent’ function includes local regulation of muscle cell activity, nerve excitability, blood flow and plasma protein extravasation. Recent data suggest that capsaicin-sensitive sensory nerves could be present in the human bladder.