What is the Origin of Cholesteryl Ester Mobilization?

The term is derived from the chemical components involved: "cholesteryl ester," the storage form of cholesterol, and "mobilization," meaning to prepare for movement or use. The underlying biological principle was established through the study of lipid metabolism and intracellular cholesterol homeostasis. This process is highly regulated and is particularly active in tissues with high cholesterol demand, such as the adrenal glands and gonads.

What is the Mechanism of Cholesteryl Ester Mobilization?

The primary enzyme responsible for this mobilization is the hormone-sensitive cholesteryl ester hydrolase (CEH), which resides in the cytoplasm. Upon activation, often by a hormonal signal like ACTH or LH, CEH cleaves the fatty acid from the cholesteryl ester, liberating free cholesterol. This newly liberated cholesterol is then trafficked to the mitochondria for the initial step of steroidogenesis, thereby linking lipid storage dynamics directly to endocrine function.

Cholesteryl Ester Mobilization ∞ Area

Cholesteryl Ester Mobilization

Meaning

Cholesteryl Ester Mobilization is the biochemical process of releasing cholesterol from its storage form within the cell, which is the cholesteryl ester molecule. Cells, particularly steroidogenic cells, store excess cholesterol by esterifying it with a fatty acid, making it more hydrophobic and inert. Mobilization involves the enzymatic hydrolysis of this ester, yielding free, biologically active cholesterol and a fatty acid. This crucial step ensures a readily available supply of cholesterol for membrane maintenance and, most importantly in endocrinology, for steroid hormone synthesis.