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Updated: Jul 29, 2026

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
Electrical and chemical control of smooth muscle activity of rabbit corpus cavernosum in vitro
C K Höppner1, C G Stief, U Jonas
1Department of Urology, Medizinische Hochschule Hannover, Germany.
Objectives:
This study sought to further elucidate the regulation of cavernous smooth muscle tone and to characterize mechanisms of cavernous activation and relaxation.
Methods:
In isolated strips of rabbit corpus cavernosum, extracellular electrical and mechanical activity were recorded simultaneously before and after pharmacologic stimulation.
Results:
Spontaneous mechanical activity was characterized by fast phasic contractions (frequency 6 to 30 min-1) associated with fluctuations of the extracellular electrical signals. Phasic activity was increased by blockade of potassium channels or by moderate activation of L-type calcium channels. Faster spikelike fluctuations occurred in the electrical activity, indicating the existence of spike discharges. All mechanical and electrical fluctuations were completely abolished by blockade of L-type calcium channels with nifedipine.
Conclusions:
Our results indicate that cavernous smooth muscle tone is regulated by both phasic and tonic activation mechanisms caused by the opening of L-type calcium channels and calcium influx through chemically controlled calcium influx/release.
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