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 effect of this signaling of high extracellular calcium results in an intracellular calcium concentration that inhibits the secretion of preformed PTH from storage granules in the parathyroid gland. In contrast to the mechanism that most secretory cells use, calcium inhibits vesicle fusion and release of PTH.