Erschienen in:
17.12.2016 | Urology - Original Paper
Importance of contraction history on muscle force of porcine urinary bladder smooth muscle
verfasst von:
Robin Menzel, Markus Böl, Tobias Siebert
Erschienen in:
International Urology and Nephrology
|
Ausgabe 2/2017
Einloggen, um Zugang zu erhalten
Abstract
Introduction
The purpose of this study was to provide a comprehensive dataset of porcine urinary bladder smooth muscle properties. Particularly, the history dependence of force production, namely force depression (FD) following shortening and force enhancement (FE) following stretch, was analysed. During active micturition, the circumference of the urinary bladder changes enormously. Thus, FD might be an important phenomenon during smooth muscle contraction.
Materials and methods
Electrically stimulated, intact urinary bladder strips from pigs (n = 10) were suspended in an aerated-filled organ bath, and different isometric, isotonic, and isokinetic contraction protocols were performed to determine the force–length and the force–velocity relation. FD and FE were assessed in concentric and eccentric contractions with different ramp lengths and ramp velocities.
Results
Bladder smooth muscles exhibit considerable amounts of FD and FE. The amount of FD increased significantly with ramp length, while FE did not change. However, FE and FD were independent of ramp velocity.
Conclusion
The results imply that smooth muscle bladder strips exhibit similar muscle properties and history-dependent behaviour compared to striated muscles. The provided dataset of muscle properties is important for bladder modelling as well as for the analyses and interpretation of dynamic bladder filling and voiding.