Related Experiment Video

Updated: Aug 24, 2026

Preparation and Utilization of Freshly Isolated Human Detrusor Smooth Muscle Cells for Characterization of 9-Phenanthrol-Sensitive Cation Currents
08:30

Preparation and Utilization of Freshly Isolated Human Detrusor Smooth Muscle Cells for Characterization of 9-Phenanthrol-Sensitive Cation Currents

Published on: January 31, 2020

Overactive bladder and incontinence in the absence of the BK large conductance Ca2+-activated K+ channel

Andrea L Meredith1, Kevin S Thorneloe, Matthias E Werner

  • 1Department of Molecular and Cellular Physiology and the Howard Hughes Medical Institute, 279 Campus Drive, Stanford University, Stanford, CA 94305, USA.

The Journal of Biological Chemistry
|June 9, 2004
PubMed

Insights

Large conductance voltage- and calcium-activated potassium (BK) channels are crucial for urinary bladder function. Their absence in mice led to enhanced bladder contractions and overactive bladder symptoms, indicating their therapeutic potential.

Area of Science:

  • Physiology
  • Pharmacology
  • Urology

Background:

  • Large conductance voltage- and calcium-activated potassium (BK) channels regulate smooth muscle excitability.
  • BK channels are implicated in urinary bladder function and are potential therapeutic targets for overactive bladder.
  • The specific role of BK channels in bladder smooth muscle requires further elucidation.

Purpose of the Study:

  • To investigate the role of the BK channel in urinary bladder function.
  • To determine the effects of BK channel deletion on bladder smooth muscle activity and voiding behavior.

Main Methods:

  • Generation of mSlo1 gene-deleted (Slo(-/-)) mice lacking the pore-forming subunit of BK channels.
  • Electrophysiological recordings to assess BK currents in urinary bladder smooth muscle cells.
  • Measurement of spontaneous and nerve-evoked bladder contractions.
  • Observation of urination frequency in wild-type and Slo(-/-) mice.

Main Results:

  • Slo(-/-) mice exhibited normal viability but moderate ataxia.
  • Urinary bladder smooth muscle cells from Slo(-/-) mice lacked BK currents, while other potassium currents and calcium transients remained unaffected.
  • Absence of BK channels resulted in significantly enhanced spontaneous and nerve-evoked bladder contractions.
  • Slo(-/-) mice displayed a marked increase in urination frequency, indicative of overactive bladder.

Conclusions:

  • BK channels play a critical role in regulating urinary bladder smooth muscle function.
  • Dysfunction or absence of BK channels leads to enhanced bladder contractility and overactive bladder symptoms, including urinary incontinence.
  • Targeting BK channels represents a promising therapeutic strategy for treating overactive bladder.

More Related Videos

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology10:26

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology

Published on: August 18, 2014

Related Concept Videos

Antihypertensive Drugs: Potassium-Sparing Diuretics01:28

Antihypertensive Drugs: Potassium-Sparing Diuretics

Liddle syndrome is a genetically inherited form of hypertension characterized by the overactivity of epithelial sodium channels in the nephron, the functional unit of the kidney. This heightened activity leads to increased sodium reabsorption and excessive excretion of potassium. To counteract this, potassium-sparing diuretics such as amiloride are used. They function by blocking these sodium channels, thereby reducing the influx of sodium into the epithelial cells and minimizing the loss of...
The Micturition Reflex01:26

The Micturition Reflex

Urination, or micturition involves the coordination of the bladder's detrusor muscle and two sphincters to ensure controlled bladder emptying.
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating urine...
Antihypertensive Drugs: Action of Calcium Channel Blockers01:18

Antihypertensive Drugs: Action of Calcium Channel Blockers

Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,...
Ligand-Gated Ion Channel Receptor: Gating Mechanism01:30

Ligand-Gated Ion Channel Receptor: Gating Mechanism

Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion01:22

Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion

The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport...
Anatomy of the Genitourinary System II: Bladder and Urethra01:19

Anatomy of the Genitourinary System II: Bladder and Urethra

The lower urinary system consists of the urinary bladder and urethra, which are essential in storing and expelling urine from the body. Together with the internal and external sphincters, these structures work together to regulate urination effectively.Anatomy of the BladderThe urinary bladder is a muscular, stretchable organ behind the pubic bone and in front of the rectum. In females, the bladder is positioned anterior to the vagina and inferior to the uterus, while in males, it is located...