Fusion of storage lysosomes in experimental lipidosis and glycogenosis.
This ultrastructural investigation on renal collecting duct cells and hepatocytes of rats deals with the question of whether or not lipid-storage lysosomes as induced by cationic amphiphilic compounds retain their ability to fuse with autophagosomes/autolysosomes. These were recognized by their glycogen content which was made to persist by means of acarbose, an inhibitor of lysosomal alpha-glucosidase. To induce lipidosis, rats were pretreated for several weeks with chloroquine or chlorphentermine; they then received combined treatment with the lipidosis-inducing drug plus acarbose. In renal collecting duct cells, mixed storage lysosomes displaying the features of both lipidosis and glycogenosis were found to predominate, indicating that fusion between lipid-laden lysosomes and glycogen-containing autophagosomes/autolysosomes was efficient. Hepatocytes also displayed some mixed storage lysosomes; these were, however, regularly accompanied, within a given hepatocyte, by greater numbers of pure lipidosis-related inclusions and pure glycogen vacuoles. This observation indicates that in hepatocytes lipid-storage lysosomes were rather reluctant to fuse, thus displaying a feature of telolysosomes which are no longer capable of participating in cellular digestion.
Lüllmann-Rauch
R
R
Watermann
D
D
D020909:Acarbose; D000818:Animals; D001343:Autophagy; D002738:Chloroquine / Q000633:toxicity; D002745:Chlorphentermine / Q000633:toxicity; D004705:Endocytosis; D005260:Female; D006008:Glycogen Storage Disease / Q000139:chemically induced / Q000473:pathology*; D007684:Kidney Tubules / Q000648:ultrastructure*; D007685:Kidney Tubules, Collecting / Q000648:ultrastructure*; D008064:Lipidoses / Q000139:chemically induced / Q000473:pathology*; D008099:Liver / Q000648:ultrastructure*; D008247:Lysosomes / Q000502:physiology*; D008561:Membrane Fusion; D051381:Rats; D011919:Rats, Inbred Strains; D014312:Trisaccharides / Q000633:toxicity; D014617:Vacuoles / Q000502:physiology
D014312:Trisaccharides; D002738:Chloroquine; D002745:Chlorphentermine; D020909:Acarbose