calciumhandling

Calcium handling refers to the complex biological processes by which cells and organisms manage the concentration of calcium ions (Ca2+). Calcium is a crucial intracellular messenger, involved in a vast array of cellular functions including muscle contraction, neurotransmitter release, gene expression, and cell division. Due to its critical roles, maintaining precise intracellular calcium levels is essential for cell survival and proper physiological function.

Cells utilize a variety of mechanisms to regulate calcium. These include the controlled movement of calcium across cell membranes, primarily through voltage-gated calcium channels, receptor-operated calcium channels, and store-operated calcium channels. Within the cell, calcium is often stored in specialized organelles like the endoplasmic reticulum and sarcoplasmic reticulum. Calcium pumps, such as the sarco/endoplasmic reticulum calcium ATPase (SERCA), actively transport calcium back into these stores, lowering cytosolic calcium levels. Conversely, calcium can be released from these stores through channels like inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs).

Disruptions in calcium handling can have significant pathological consequences. Imbalances, leading to either excessive calcium (calcium overload) or insufficient calcium, are implicated in numerous diseases, including neurodegenerative disorders, cardiovascular diseases, and cancer. Understanding the intricate mechanisms of calcium handling is therefore a key area of research in physiology and medicine.