Prostasomes
（重定向自Prostasome）
Prostasomes were discovered in 1978 as submicron membranous vesicles (40-500 nm in diameter) secreted by the prostate gland epithelial cells into seminal fluid. They possess an unusual lipid composition and a tight and highly ordered structure of their lipoprotein membranes resembling lipid raft. The physiological role of prostasomes implicates improvement of sperm motility and protection against attacks from the female immune defense during the passage to the egg.