2. in psychiatry, an unconscious defense mechanism in which unacceptable ideas, fears, and impulses are thrust out or kept out of consciousness. 3. gene r. enzyme repression interference, usually by the endproduct of a pathway, with synthesis of the enzymes of that pathway. gene repression the inhibition of gene transcription of an operon; in prokaryotes repressor binding to the operon is involved.
Hyperkalemia can result from increased potassium intake, decreased potassium excretion, or a shift of potassium from the intracellular to the extracellular space. The most common causes involve decreased excretion. Alone, excessive intake or an extracellular shift is distinctly uncommon.
The two ions which are most conspicuously regulated are sodium and potassium. The cell membrane is 100 times more permeable to potassium than sodium. The concentration of sodium is highest in extracellular fluid while potassium is highest in intracellular fluid.