Modulatory effects of intravesical P2X2/3R inhibition on the lower urinary tract electromyographic properties and voiding function of female rats w…
Authors of this article are:
Salazar BH Hoffman KA Zhang C Zhang Y Cruz Y Boone TB Munoz A.
A summary of the article is shown below:
OBJECTIVES: To evaluate the role that intravesical P2X2/3 purinergic receptors (P2X2/3R) play in early and advanced neurogenic lower urinary tract (LUT) dysfunction after contusion spinal cord injury (SCI) in female rats.MATERIALS AND METHODS: Female Sprague-Dawley rats received a thoracic Th8/Th9 spinal cord contusion with either force of 100 kDynes (kDy; moderate) or 150 kDynes (severe); Sham animals had no injury. Evaluations on urethane-anesthetized rats were at either two or four weeks post-SCI. LUT electrical signals and changes in bladder pressure were simultaneously recorded using cystometry and a set of custom-made flexible microelectrodes before and after intravesical application of the P2X2/3R antagonist AF-353 (10 μM) to determine the contribution of P2X2/3R-mediated LUT modulation.RESULTS: Severe SCI significantly increased bladder contraction frequency, and reduced both bladder pressure amplitude and intraluminal-pressure high-frequency oscillations (IPHFO). Intravesical P2X2/3R inhibition did not modify bladder pressure nor IPHFO in Sham and moderate SCI animals, although did increase intercontractile interval. At two weeks after SCI, Sham and moderate-SCI animals presented significant LUT electromyographic activity during voiding, with a noticeable reduction in LUT electrical signals observed at four weeks post-SCI. Intravesical inhibition of P2X2/3R increased the intercontractile interval in Sham and moderate SCI rats at either time point, but had no effect on animals with severe SCI. The external urethral sphincter (EUS) showed strong, and P2X2/3R-independent electrical signals in either Sham or moderate-SCI rats in the early SCI stage. At four weeks post-SCI the responsiveness of the EUS was significantly attenuated, independently of SCI intensity.CONCLUSIONS: This study demonstrates that electrophysiological properties of the LUT are progressively impaired depending on SCI intensity and that intravesical P2X2/3R inhibition can attenuate electrical activity in the neurogenic LUT at early, but not at semi-chronic SCI. This translational study should be useful for planning clinical evaluations. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.
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This article is a good source of information and a good way to become familiar with topics such as: Electromyography;P2X2 purinergic receptor;P2X3;cystometry;lower urinary tract;spinal cord injury.
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