Related Experiment Videos
Multiple transport systems for organic cations in renal brush-border membrane vesicles
Y Miyamoto1, C Tiruppathi, V Ganapathy
1Department of Cell and Molecular Biology, Medical College of Georgia, Augusta 30912-2100.
The American Journal of Physiology
|April 1, 1989
Summary
Rabbit kidney brush-border membranes utilize a guanidine-H+ antiport system for guanidine uptake, driven by the proton gradient. This indicates multiple organic cation transporters in renal membranes.
Area of Science:
- Renal Physiology
- Membrane Transport
- Biochemistry
Background:
- Brush-border membrane vesicles (BBMVs) from rabbit renal cortex are crucial for studying nutrient and waste reabsorption.
- Understanding the transport mechanisms of organic cations is vital for renal drug handling and toxin excretion.
Purpose of the Study:
- To investigate the characteristics and mechanism of guanidine uptake in rabbit renal BBMVs.
- To identify the driving forces and carrier systems involved in renal organic cation transport.
Main Methods:
- Isolation of brush-border membrane vesicles from rabbit renal cortex.
- Measurement of guanidine uptake under various conditions, including ion gradients and presence of inhibitors.
- Kinetic analysis of transporter systems.
Main Results:
- Guanidine uptake is stimulated by an outwardly directed H+ gradient, suggesting a guanidine-H+ antiport mechanism.
- Specific organic cations significantly inhibited guanidine uptake, while others had minimal effect.
- Kinetic analysis revealed at least two distinct carrier systems for guanidine, distinct from the single system for tetraethylammonium.
Conclusions:
- Renal brush-border membranes employ a proton-gradient-driven guanidine-H+ antiport system.
- Multiple carrier systems for organic cations exist in the renal brush border, contributing to the complexity of renal transport.