title: Initial kinetics of lysosomal enzyme secretion and superoxide anion generation by human polymorphonuclear leukocytes.
abstract: Human polymorphonuclear leukocytes (PMN) exposed to particulate and soluble stimuli secrete lysosomal enzymes. These stimuli cause prompt (less than 10 sec) changes in membrane potential followed 30--45 sec later by superoxide anion (O-2.) production. We describe a new technique utilizing flow dialysis apparatus which monitors the first stages of lysosomal enzyme release with a resolution of approximately 6 sec. Secretion of beta-glucuronidase from cytochalasin B-treated PMN could be detected 19+/-5 sec after exposure to the chemotactic peptide N-formylmethionylleucylphenylalanine (FMLP). The "lag" times for release of this enzyme were different for other stimuli: 35+/-8 sec (BSA/anti-BSA immune complex); 48+/-8 sec (serum-treated zymosan, "STZ"); 60+/-25 sec (calcium ionophore A23187). The lag times for lysozyme release were less dependent upon the stimulus presented (28+/-16 sec for FMLP, 28+/-8 sec fo BSA/anti-BSA, 32+/-10 sec for STZ, and 38+/-8 seconds for Con A); only A23187 had a long lag period: 74+/-27 sec. Lag periods for the onset of O-2. production (measured by the same mathematical criteria) were comparable to those for beta-glucuronidase release: 21+/-4 sec for FMLP, 43+/-14 sec for BSA/anti-BSA, 62+/-7 sec for Con A, and 50+/-13 sec for A23187. Changes in FMLP dose up to 100-fold affected the magnitudes of O-2. generation and beta-glucuronidase release, but did not alter the time required for the onset of these processes. A variety of agents, such as corticosteroids, colchicine, 2-deoxyglucose, and N-ethyl maleimide, also affected the magnitudes of the responses, but not the lag periods when FMLP was used as the stimulus. When BSA/anti-BSA immune complex was used as the stimulus, 2-deoxyglucose and N-ethyl maleimide increased the lag period for superoxide anion generation, but not for lysosomal enzyme release. This new flow dialysis technique has permitted us to demonstrate the O-2. production and lysosomal enzyme secretion are concurrent but dissociable processes which are subsequent to earlier responses of the granulocyte-to-ligand-receptor interactions as reflected by changes in membrane potential.
mesh_terms: D002498:Centrifugation / Q000379:methods; D003208:Concanavalin A / Q000494:pharmacology; D003956:Dialysis / Q000295:instrumentation / Q000379:methods; D007700:Kinetics; D008247:Lysosomes / Q000187:drug effects / Q000201:enzymology*; D009504:Neutrophils / Q000201:enzymology* / Q000378:metabolism; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D015054:Zymosan / Q000494:pharmacology
chemical_list: D003208:Concanavalin A; D013481:Superoxides; D012710:Serum Albumin, Bovine; D015054:Zymosan; D010100:Oxygen