Lysosomal enzyme secretion by macrophages during intracellular storage of particles.
Cultured mouse peritoneal macrophages containing previously endocytosed zymosan or small-fibre asbestos (but not latex or sucrose) were shown to release selectively into the medium the lysosomal hydrolase beta-N-acetylglucosaminidase. Thus macrophage lysosomal enzyem secretion was experimentally dissociated from endocytosis (as the residual external particles were washed away from the cells). The cells remained viable, and total activities of both N-acetyl-beta-D-glucosaminidase and of lactate dehydrogenase (a cytosol enzyme) rose with time. The relevance of such secretion by macrophages containing stored materials to chronic inflammatory processes is discussed.
D000118:Acetylglucosaminidase / Q000378:metabolism*; D000818:Animals; D001194:Asbestos / Q000494:pharmacology*; D001202:Ascitic Fluid / Q000166:cytology; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D004705:Endocytosis; D006596:Hexosaminidases / Q000378:metabolism*; D007249:Inflammation / Q000201:enzymology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008247:Lysosomes / Q000201:enzymology*; D008264:Macrophages / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D015054:Zymosan / Q000494:pharmacology*
D001194:Asbestos; D015054:Zymosan; D007770:L-Lactate Dehydrogenase; D006596:Hexosaminidases; D000118:Acetylglucosaminidase