数据之源，洞见之始

Metabolite Card

Note

24-Hydroxycholesterol (24OHC) is almost exclusively formed in the brain. The enzymatic conversion of CNS cholesterol to 24OHC, which readily crosses the blood-brain barrier, is the major pathway for brain cholesterol elimination and brain cholesterol homeostasis maintenance. The enzyme mediating this conversion has been characterized at the molecular level as cholesterol 24-hydroxylase (EC 1.14.13.98, CYP46) and is mainly located in neurons. Like other oxysterols, 24OHC is efficiently converted into normal bile acids or excreted in bile in its sulfated and glucuronidated form. Levels of 24OHC in the circulation decrease with age in infants and children. In adults, however, the levels appear to be stable. There is accumulating evidence pointing toward a potentially important link between cholesterol, beta-amyloid, and Alzheimer's disease. Patients with active demyelinating diseases had increased levels of 24OHC in cerebrospinal fluid (CSF). Patients with Alzheimer's disease have slightly increased levels of 24OHC in CSF. Patients with multiple sclerosis have a tendency to have higher levels of 24OHC during active periods. (PMID: 15061359, 14574622). 24-Hydroxycholesterol has been found to accumulate in hereditary hypercholesterolemia, an inborn error of metabolism.