calcium paradox


Also found in: Acronyms.

calcium paradox

A phenomenon described in chronically ischaemic (and hypocalcemic) smooth and cardiac muscles which, when re-exposed to normal Ca2+ levels, become overloaded with Ca2+, enter a sustained contracted state and die, due to:
(1) Ca2+ loading by hypoxic mitochondria; and
(2) Exacerbation of ischaemia by hypercalcemia-induced vasospasm, triggering thromboxane and prostaglandin release.