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.
Physiology of Potassium Handling. Potassium (K+) is the most abundant cation in the body. About 90% of total body potassium is intracellular and 10% is in extracellular fluid, of which less than 1% is composed of plasma.
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.