Influence of Protein Synthesis Inhibitors on Neutral Red-Induced Autophagocytosis in Chicken Pancreatic Acinar Cells [antikvár]

Acta biol. Acad. Sci. hung., 31 (1-3), 165-175 (1980) INFLUENCE OF PROTEIN SYNTHESIS INHIBITORS ON NEUTRAL RED-INDUCED AUTOPHAGOCYTOSIS IN CHICKEN PANCREATIC ACINAR CELLS* Anna L. Kiss**, G. Réz and J. Kovács DEPARTMENT OF GENERAL ZOOLOGY, EÖTVÖS LORÁND UNIVERSITY, BUDAPEST (Received 1980—02—15) Abstract Administration of neutral red to chicks resulted in an appearance of autophagic vacuoles in the pancreatic exocrine cells, containing mainly fragments of the endoplasmic reticulum, as weU as Golgi elements, mitochondria and zymogen granules. The time course of the morphological changes was followed. The translational inhibitors cyclo-heximide and emetine did not induce injury, even they were equally found to exert a dose dependent, temporary, preventive effect against autophagocytosis induced by neutral red. This protection might be related to the capability of the drugs for stabilizing the polyribosomes and thereby preserving the structural integrity of the granular endoplasmic reticulum membrane. Introduction Autophagocytosis is a process of intracellular degradation during which parts of the cytoplasm are segregated by lysosomal or prelysosomal membranes, and thereby transferred into the cavity of the vacuolar compartment Avhere the engulfed structures and macromolecules subsequently undergo digestion due to the activity of lysosomal enzymes [7, 11, 21, 30, 42]. The segregation may be effected either by pre-existing members of the vacuolar apparatus, such as lysosomes [7, 54], GERL [39, 40] and heterophagic vacuoles [15] or by an isolating cisterna (a pair of membrane) not containing the lysosomal marker enzyme acid phosphatase [2, 10, 48]. In the later case, the nascent double membrane-limited prelysosomes containing virtually undegraded material are termed autophagosomes gaining acid hydrolases later by fusion with lysosomes [9] to form autolysosomes, within which digestion of the segregated material occurs. Since the enzyme content of these granules is not visualized by the routine electron microscopic methods, the term autophagic vacuole is widely used for any bodies of autophagic origin. Autophagocytosis is known to play an important role in normal cellular functions, such as intracellular protein degradation [6, 38], structural and functional remodelling of cells [3, 14, 18, 19, 40] and involutive processes [32]. * Dedicated to Prof. I. TÖRŐ on his 80th birthday. ** Present address: 2nd Department of Anatomy, Semmelweis University Medical School, Budapest. Acta Biologica Academiae Scientiarum Hungaricae 31, 1980