Related Experiment Video
Updated: Jul 16, 2026

07:42
Magnetic Levitation Coupled with Portable Imaging and Analysis for Disease Diagnostics
Published on: February 19, 2017
Monovalent cation transport in irreversibly sickled cells
The Journal of Clinical Investigation
|August 1, 1978
Summary
Sickle cell blood cells (ISCs) show reduced active transport of cations. This occurs despite normal Na, K-ATPase activity in ISC membranes, suggesting internal cellular factors inhibit cation transport in sickle cell disease.
Area of Science:
- Hematology
- Cell Physiology
- Biochemistry
Background:
- Sickle cell disease (SCD) is characterized by abnormal red blood cells, including irreversibly sickled cells (ISCs).
- Cation transport is crucial for red blood cell function and survival.
- Understanding transport defects in ISCs is vital for SCD pathophysiology.
Purpose of the Study:
- To investigate monovalent cation fluxes in different sickle cell subpopulations.
- To compare active and passive cation transport in normal, mature discoid, and irreversibly sickled cells (ISCs).
- To elucidate the mechanisms behind impaired cation transport in ISCs.
Main Methods:
- Separation of sickle cell blood into reticulocytes, mature discoid cells, and ISCs using discontinuous Stractan II density gradients.
- Measurement of active and passive monovalent cation fluxes in separated cell populations.
- Assay of Na, K-ATPase activity in isolated ISC membranes.
Main Results:
- ISC-rich populations exhibited decreased active cation transport.
- Passive cation permeability (Rb flux) in ISCs was comparable to normal cells.
- Ouabain-sensitive Na, K-ATPase activity in ISC membranes was normal.
Conclusions:
- The reduced active cation transport in intact ISCs is not due to intrinsic defects in the Na, K-ATPase enzyme.
- Internal cellular factors within ISCs likely inhibit active Na and K transport.
- This finding suggests a regulatory mechanism affecting cation homeostasis in sickle cell disease.
More Related Videos
Related Concept Videos
Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Multiple Allele Traits
The Concept of Multiple Allelism
Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Transcellular 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...
Membrane Asymmetry Regulating Transporters
Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Active Transport
Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition.
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...

