Labile iron pool (LIP)

The **labile iron pool** (LIP) is a dynamic, heterogenous pool of intracellular and extracellular iron that is loosely bound, redox-active, and readily exchangeable between ligands or chelators[1][4][7]. Unlike iron stored in ferritin or bound to transferrin, LIP represents a transient reservoir of iron that participates in essential metabolic processes, including enzyme catalysis, heme and iron-sulfur cluster biosynthesis, and cellular signal transduction[1][3][7]. However, because of its redox activity, the LIP can catalyze the formation of highly reactive oxygen species (ROS) through Fenton chemistry, posing a risk of oxidative injury and cell damage when present in excess[1][4][6]. Abnormal LIP levels are implicated in iron overload conditions, neurodegenerative diseases, cancer, and other pathologies, and therapeutic strategies such as iron chelator drugs are employed to reduce the toxic effects of LIP in affected individuals[2][6]. Measurement of LIP levels in clinical and research settings is important for monitoring iron status and guiding chelation therapy[6].

Other names

Labile cell iron (LCI)Non-transferrin bound iron (when referring to labile plasma iron)"Free" intracellular ironChelatable iron

For iron chelators: - Bind and sequester labile iron, prevent Fenton chemistry and ROS generation - Promote excretion of excess iron