Activated Factor VII, also known as Factor VIIa, is a crucial protein involved in the coagulation cascade, a complex process that plays a pivotal role in maintaining the integrity and functioning of the circulatory system. It is a component of the extrinsic pathway, one of the two pathways through which coagulation is initiated.
Factor VII is produced by the liver and circulates in the blood as an inactive precursor, known as Factor VII. However, when tissue damage occurs, particularly in situations where blood vessels are injured, Factor VII is converted into its active form, Factor VIIa, through a series of enzymatic reactions. This conversion is mainly triggered by the presence of tissue factor, a transmembrane protein released by damaged tissues.
Once activated, Factor VIIa functions as an enzyme, forming a complex with tissue factor and calcium ions. This complex activates Factor X, a key enzyme responsible for converting prothrombin into thrombin. Thrombin, in turn, prompts the conversion of fibrinogen to fibrin, which plays a crucial role in forming a mesh-like structure, the blood clot, that helps to cease bleeding at the site of injury.
Medical professionals may utilize activated Factor VII, either obtained from natural sources or produced synthetically, in certain clinical scenarios where severe bleeding occurs and conventional treatments are ineffective. It is administered intravenously to promote clot formation in specific patients, such as those with hemophilia or other bleeding disorders, or individuals undergoing surgery or are at risk of excessive bleeding. The usage of activated Factor VII requires careful monitoring due to its potential side effects, such as thrombosis or embolism formation.
