Effects of FMLP and LPS on [Ca2+]i of peritoneal exudate polymorphonuclear leukocytes following onset of inflammation.
Because a general study of activated neutrophils may have relevance to periodontal diseases and accompanying inflammation, we studied a function of mouse polymorphonuclear leukocytes (PMNs) that exude into the peritoneal cavity in response to inflammation caused by i.p. injection of 2% casein. The effects of E. coli-lipopolysaccharide (E-LPS) and a chemotactic factor, N-formyl-N-methionyl-N-leucyl-L-phenylalanine (FMLP), on the level of intracellular calcium ([Ca2+]i) in these PMNs were examined. From analysis made with a laser cytometer (ACAS 570), the PMNs in exudates harvested 3-9 h after the onset of inflammation were shown to undergo [Ca2+]i elevation in response to 10(-6) M FMLP. The peak concentration of [Ca2+]i elicited by FMLP was highest in exudate cells 6 h after casein injection. In addition, about 65% of the PMNs in the 3-h exudate were FMLP sensitive displaying an elevated [Ca2+]i, whereas more than 85% of them in 6- and 9-h exudates became FMLP sensitive. Also, the maximum level of [Ca2+]i after FMLP stimulation was potentiated by pretreatment of the cells with E-LPS (0.2 microgram/ml). The present study suggests that PMNs induced by casein injection and appearing in mouse peritoneal exudate at different times possess significantly different ability to undergo [Ca2+]i elevation, and different susceptibility toward a chemotactic factor, FMLP.
D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology*; D002118:Calcium / Q000819:agonists / Q000032:analysis*; D002364:Caseins; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D004926:Escherichia coli; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000737:chemistry* / Q000187:drug effects* / Q000276:immunology; D010538:Peritonitis / Q000139:chemically induced / Q000276:immunology; D015398:Signal Transduction
D002364:Caseins; D008070:Lipopolysaccharides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium