On the question of the ultrastructure and composition of corpus intra cristam after local methylcholanthrene application

Abstract

The study deals with the morphology and composition of the corpora intra cristam in the epidermis of mice after methylcholanthrene application. The bodies appear in all investigated samples 3 weeks after initiation of treatment. In the initial phase, they are probably not always surrounded by a membrane. The limiting membrane is often jaggedly extended, a fact which probably can be explained by the participation of several cristae. Disintegration of the corpus intra cristam-bearing mitochondria and the possibly extramitochondrial appearance of these bodies are discussed. In order to investigate the chemical composition of corpora intra cristam, extraction with chloroform—methanol and with hexane was performed; moreover, pronase digestion and the demonstration of cytochrome oxidase activity was carried out. It was concluded that the investigated intramitochondrial bodies are in all probability composed of a protein with associated phospholipids. Furthermore, it was possible to demonstrate cytochrome oxidase activity mainly in the peripheral zone of the inclusions, which points to the participation of mitochondrial cristae in the formation of the corpora intra cristam.