chapter  4
34 Pages

An Overview of Peroxisome Proliferation

Peroxisomes are cytoplasmic organelles that contain a homogeneous, granular, and electron-dense matrix surrounded by a single membrane (1). Nearly all eukaryotic cells contain peroxisomes, but the size and content vary from organ to organ (2, 3). Hepatic peroxisomes are round, measuring between 0.5 and 1 J,Lm in diameter, and account for approximately 1-2% of the cytoplasmic volume in the rat liver (2, 4, 5). These organelles carry out a variety of enzymatic functions, many of which are involved in lipid metabolism, including H202 degradation, fatty acid activation and oxidation, plasmalogen (ether lipid) biosynthesis, and cholesterol biosynthesis (1-8).