Analysis of Oxysterols.

Oxysterols are oxygenated derivatives of cholesterol formed in the human body or ingested in the diet. By modulating the activity of many proteins (for instance, liver X receptors, oxysterol-binding proteins, some ATP-binding cassette transporters), oxysterols can affect many cellular functions and influence various physiological processes (e.g., cholesterol metabolism, membrane fluidity regulation, intracellular signaling pathways). Due to their crucial role, it is important to be able to quantify them in pathological conditions. The method described here permits to measure the content of oxysterol in plasma, cell, or media using GC-MS.