Abstract

Purpose: The external urethral sphincter (EUS) is regarded as an important structure involved in urinary continence and micturition, so a rodent animal model was employed to investigate these urinary functions. However, few studies have compared the physiological and histochemical characteristics of the EUS between male and female rats in detail. The aims of this study were to extensively examine the properties of the EUS in rats of both sexes via cystometric electromyography (EMG) and histochemical measurements. Methods: EUS-EMG and intravesical pressure were simultaneously recorded using continuous cystometric monitoring in order to provide a quantitative evaluation of EUS activity and voiding function. A histochemical examination of the striated EUS muscle was also performed using immunolabeling techniques to study the myosin heavy chain isoforms. Results: Cystometric measurements, including the bladder volume threshold, contraction amplitude, contraction duration, contraction area, intercontraction interval, and voided volume, were significantly larger in male rats in comparison with female rats. In addition, a longer EUS burst period, silent period, and total silent period and a larger number of silent periods, a higher frequency of burst discharges, and a shorter active period were found in male rats. Only type II fibers (100%) were seen in the striated urethral muscle of the upper segment of the urethra in male rats, whereas in females both type I and II striated muscle fibers were present in all segments of the urethra with proportions ranging from of 6-14% for type I and 86-94% for type II fibers. Conclusion: This study investigated both the physiological and histochemical differences in the properties of the EUS that underlie sexually dimorphic EUS burst activities in rats. The present study provides useful information for future urological research.

Original languageEnglish
Pages (from-to)157-164
Number of pages8
JournalJournal of Experimental and Clinical Medicine(Taiwan)
Volume4
Issue number3
DOIs
Publication statusPublished - Jun 2012

Fingerprint

Urethra
Sex Characteristics
Striated Muscle
Electromyography
Myosin Heavy Chains
Urination
Rodentia
Protein Isoforms
Urinary Bladder
Animal Models
Immunohistochemistry
Pressure
Muscles

Keywords

  • Electromyography
  • External urethral sphincter
  • Intravesical pressure
  • Myosin heavy chain

ASJC Scopus subject areas

  • Medicine(all)

Cite this

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title = "Sex Differences in the External Urethral Sphincter Activity of Rats",
abstract = "Purpose: The external urethral sphincter (EUS) is regarded as an important structure involved in urinary continence and micturition, so a rodent animal model was employed to investigate these urinary functions. However, few studies have compared the physiological and histochemical characteristics of the EUS between male and female rats in detail. The aims of this study were to extensively examine the properties of the EUS in rats of both sexes via cystometric electromyography (EMG) and histochemical measurements. Methods: EUS-EMG and intravesical pressure were simultaneously recorded using continuous cystometric monitoring in order to provide a quantitative evaluation of EUS activity and voiding function. A histochemical examination of the striated EUS muscle was also performed using immunolabeling techniques to study the myosin heavy chain isoforms. Results: Cystometric measurements, including the bladder volume threshold, contraction amplitude, contraction duration, contraction area, intercontraction interval, and voided volume, were significantly larger in male rats in comparison with female rats. In addition, a longer EUS burst period, silent period, and total silent period and a larger number of silent periods, a higher frequency of burst discharges, and a shorter active period were found in male rats. Only type II fibers (100{\%}) were seen in the striated urethral muscle of the upper segment of the urethra in male rats, whereas in females both type I and II striated muscle fibers were present in all segments of the urethra with proportions ranging from of 6-14{\%} for type I and 86-94{\%} for type II fibers. Conclusion: This study investigated both the physiological and histochemical differences in the properties of the EUS that underlie sexually dimorphic EUS burst activities in rats. The present study provides useful information for future urological research.",
keywords = "Electromyography, External urethral sphincter, Intravesical pressure, Myosin heavy chain",
author = "Shih-Ching Chen and Chien-Hung Lai and Fan, {Wen Jia} and Chih-Wei Peng",
year = "2012",
month = "6",
doi = "10.1016/j.jecm.2012.04.006",
language = "English",
volume = "4",
pages = "157--164",
journal = "Journal of Experimental and Clinical Medicine",
issn = "1878-3317",
publisher = "Elsevier Taiwan LLC",
number = "3",

}

TY - JOUR

T1 - Sex Differences in the External Urethral Sphincter Activity of Rats

AU - Chen, Shih-Ching

AU - Lai, Chien-Hung

AU - Fan, Wen Jia

AU - Peng, Chih-Wei

PY - 2012/6

Y1 - 2012/6

N2 - Purpose: The external urethral sphincter (EUS) is regarded as an important structure involved in urinary continence and micturition, so a rodent animal model was employed to investigate these urinary functions. However, few studies have compared the physiological and histochemical characteristics of the EUS between male and female rats in detail. The aims of this study were to extensively examine the properties of the EUS in rats of both sexes via cystometric electromyography (EMG) and histochemical measurements. Methods: EUS-EMG and intravesical pressure were simultaneously recorded using continuous cystometric monitoring in order to provide a quantitative evaluation of EUS activity and voiding function. A histochemical examination of the striated EUS muscle was also performed using immunolabeling techniques to study the myosin heavy chain isoforms. Results: Cystometric measurements, including the bladder volume threshold, contraction amplitude, contraction duration, contraction area, intercontraction interval, and voided volume, were significantly larger in male rats in comparison with female rats. In addition, a longer EUS burst period, silent period, and total silent period and a larger number of silent periods, a higher frequency of burst discharges, and a shorter active period were found in male rats. Only type II fibers (100%) were seen in the striated urethral muscle of the upper segment of the urethra in male rats, whereas in females both type I and II striated muscle fibers were present in all segments of the urethra with proportions ranging from of 6-14% for type I and 86-94% for type II fibers. Conclusion: This study investigated both the physiological and histochemical differences in the properties of the EUS that underlie sexually dimorphic EUS burst activities in rats. The present study provides useful information for future urological research.

AB - Purpose: The external urethral sphincter (EUS) is regarded as an important structure involved in urinary continence and micturition, so a rodent animal model was employed to investigate these urinary functions. However, few studies have compared the physiological and histochemical characteristics of the EUS between male and female rats in detail. The aims of this study were to extensively examine the properties of the EUS in rats of both sexes via cystometric electromyography (EMG) and histochemical measurements. Methods: EUS-EMG and intravesical pressure were simultaneously recorded using continuous cystometric monitoring in order to provide a quantitative evaluation of EUS activity and voiding function. A histochemical examination of the striated EUS muscle was also performed using immunolabeling techniques to study the myosin heavy chain isoforms. Results: Cystometric measurements, including the bladder volume threshold, contraction amplitude, contraction duration, contraction area, intercontraction interval, and voided volume, were significantly larger in male rats in comparison with female rats. In addition, a longer EUS burst period, silent period, and total silent period and a larger number of silent periods, a higher frequency of burst discharges, and a shorter active period were found in male rats. Only type II fibers (100%) were seen in the striated urethral muscle of the upper segment of the urethra in male rats, whereas in females both type I and II striated muscle fibers were present in all segments of the urethra with proportions ranging from of 6-14% for type I and 86-94% for type II fibers. Conclusion: This study investigated both the physiological and histochemical differences in the properties of the EUS that underlie sexually dimorphic EUS burst activities in rats. The present study provides useful information for future urological research.

KW - Electromyography

KW - External urethral sphincter

KW - Intravesical pressure

KW - Myosin heavy chain

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