Related Experiment Video
Updated: Jul 25, 2026
06:36
A Decentralized (Ex Vivo) Murine Bladder Model with the Detrusor Muscle Removed for Direct Access to the Suburothelium during Bladder Filling
Published on: November 28, 2019
Hydrostatic pressure-regulated ion transport in bladder uroepithelium
Edward C Y Wang1, Jey-Myung Lee, John P Johnson
1Department of Medicine, University of Pittsburgh, Pennsylvania 15261, USA.
American Journal of Physiology. Renal Physiology
|May 29, 2003
Summary
Hydrostatic pressure increases sodium absorption in the bladder uroepithelium via epithelial sodium channels. It also triggers chloride and potassium secretion through stretch-activated channels, impacting electrolyte balance.
Area of Science:
- Physiology
- Urology
Background:
- The bladder uroepithelium regulates ion transport.
- Understanding mechanosensory transduction is crucial for bladder function.
Purpose of the Study:
- To investigate the effects of hydrostatic pressure on ion transport in rabbit bladder uroepithelium.
- To identify ion channels involved in pressure-induced transport.
Main Methods:
- Isolated rabbit uroepithelium mounted in Ussing chambers.
- Mechanical stimulation via hydrostatic pressure.
- Measurement of ion fluxes (Na+, Cl-, K+) and channel blocker sensitivity.
Main Results:
- Increased hydrostatic pressure enhanced mucosal-to-serosal Na+ absorption via amiloride-sensitive channels.
- Hydrostatic pressure induced Cl- and K+ secretion.
- K+ secretion involved stretch-activated nonselective cation channels sensitive to amiloride, tetraethylammonium, Ba2+, and Gd3+.
Conclusions:
- Hydrostatic pressure significantly alters ion transport in the bladder uroepithelium.
- This pressure-induced transport may be vital for electrolyte homeostasis, volume regulation, and mechanosensory transduction.
Related Concept Videos
01:23Transcellular Transport of Solutes
Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...
01:23Formation of Concentrated Urine
There is a gradient of solutes in the interstitial fluid from the renal cortex through the medulla, known as the medullary osmotic gradient. The juxtamedullary nephrons establish and maintain this gradient using countercurrent mechanisms with loops extending deep into the medulla. These nephrons also use countercurrent mechanisms to regulate urine volume and concentration. The interaction between the descending and ascending limbs of the nephron loop creates an osmotic gradient through...
01:18Fluid Movement Between Compartments
The force applied by fluids against a surface, known as hydrostatic pressure, initiates the transfer of fluid among different compartments. Within our blood vessels, the blood's hydrostatic pressure is a result of the heart's pumping action. At the arteriolar end of capillaries, hydrostatic pressure (capillary blood pressure) exceeds the opposing colloid osmotic pressure created primarily by plasma proteins like albumin. This discrepancy in pressure propels plasma and nutrients from the...
01:17Pore Transport and Ion-Pair Transport
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
01:22Physiology 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...
01:20Physiology of the Genitourinary System III: Urine Concentration and Dilution
The kidneys concentrate or dilute urine to maintain water and electrolyte balance. Nephrons, particularly the loop of Henle, play a crucial role in this process through the countercurrent multiplication system. This system establishes a high osmolarity in the renal medulla, which is essential for water reabsorption. In the loop of Henle’s descending limb, water is reabsorbed into the surrounding medulla due to its permeability to water. In contrast, the ascending limb actively transports...