CYTOCHEMICAL ANALYSIS OF ORGANELLE DEGRADATION IN PHAGOSOMES AND APOPTOTIC CELLS OF THE MUCOID EPITHELIUM OF MICE

The activities of mitochondrial cytochrome oxidase and of peroxisomal catalase in the phagolysosomes and apoptotic bodies of mucoid epithelial cells [from mouse stomach] were analyzed. Tissues from 2-6 day old mice were used. The activity of acid phosphatase in lysosomes was estimated. The presence of cytochrome oxidase was confirmed in well-preserved mitochondria inside phagosomes. Mitochondria in cells exhibiting apoptotic death also showed cytochrome oxidase activity. The enzyme activity in swollen mitochondria ceases before the membranes of the cristae disappear completely. Apoptotic bodies are phagocytosed by sister mucoid cells and are then digested inside the cell. Phagosomes containing already degraded mitochondria still show active catalase in sequestered peroxisomes. The acid phosphatase involved in degradation of phagocytosed material originates from endocytosed lysosomes and from primary and secondary lysosomes which fuse with the membranes of phagosomes.