Calcium buffering describes the processes which help stabilise the concentration of free calcium ions within cells, in a similar manner to how pH buffers maintain a stable concentration of hydrogen ions.
[1] The majority of calcium ions within the cell are bound to intracellular proteins, leaving a minority freely dissociated.
[2] The regulation of free calcium is of particular importance in excitable cells like cardiomyocytes[3] and neurons.
[6] Alterations in calcium buffering within the cytosol have been implicated in the tendency to arrhythmias (abnormal cardiac rhythms) in some genetic mutations known to cause hypertrophic cardiomyopathy.
[7] Genetic mutations affecting calsequestrin are responsible for an autosomal recessive form of catecholaminergic polymorphic ventricular tachycardia, an inherited cardiac condition that can lead to sudden death.