Electron Microscopic Observation of Experimentally Induced Comedones in Rabbit

Myung, Ki Bum

Abstract

Accurnulation of keratinized cells within the infundibulum of pilosebaceous canal is important in the pathogenesis of acne. Light and electron microscopic study of experimentally induced comedones, from the rabbit's external ear canal, was performed to define the earIy morphologic changes within and around the epithelial lining of the comedones. In light microscopic observation, early comedone was composed of loose cohesive horny cells and late comedone was composed of a mixture of loose and tight cohcsive horny cells. Cohesion between horny cells occured, in eIectron microscopic study, in two different ways: initially, by the persistence of desmosomes; later, and to a lesser extent, by tight junctions, which tightly bound the horny cells together. Multiple lipid droplets within the horny ceIls and a gradual decrease in the numbrane coating granules were observed.