sodium ion export across plasma membrane

Definition

Target type: biologicalprocess

The directed movement of sodium ions from inside of a cell, across the plasma membrane and into the extracellular region. [GOC:vw, PMID:14674689]

Sodium ion export across the plasma membrane is a fundamental process in maintaining cellular homeostasis and regulating various physiological functions. This process is primarily driven by the activity of specialized transmembrane proteins known as sodium-potassium pumps (Na+/K+ ATPases). These pumps utilize the energy derived from ATP hydrolysis to actively transport three sodium ions (Na+) out of the cell and two potassium ions (K+) into the cell against their respective electrochemical gradients. The export of Na+ from the cell is crucial for several reasons: 1. **Maintaining osmotic balance:** The outward movement of Na+ reduces the intracellular concentration of this ion, preventing water from rushing into the cell and causing it to swell. 2. **Generating electrochemical gradients:** The outward movement of Na+ creates a sodium concentration gradient across the plasma membrane, with higher concentration outside the cell. This gradient serves as a driving force for various secondary active transport mechanisms that rely on the Na+ gradient to move other molecules across the membrane. 3. **Regulating membrane potential:** The export of Na+ contributes to the establishment and maintenance of the resting membrane potential, which is essential for nerve impulse propagation, muscle contraction, and other cellular processes. 4. **Maintaining cell volume:** The Na+/K+ pump activity indirectly influences cell volume by regulating the intracellular concentration of osmotically active solutes, including Na+. The process of sodium ion export is tightly regulated by various factors, including intracellular Na+ concentration, ATP availability, and hormonal signaling. Disruptions in sodium ion export can lead to significant cellular dysfunction and contribute to various diseases. For instance, mutations in the Na+/K+ pump genes can cause disorders affecting nerve and muscle function. Furthermore, alterations in sodium ion export can play a role in cardiovascular diseases, hypertension, and kidney dysfunction.'
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Proteins (13)

Compounds (28)