title: Lack of correlation between calcium mobilization and respiratory burst activation induced by chemotactic factors in rabbit polymorphonuclear leukocytes.
abstract: Low concentrations of FMLP, partially purified rabbit C5a, leukotriene B4 and platelet activating factor induced a rapid rise of intracellular free Ca2+ in rabbit polymorphonuclear leukocytes. However, the four factors differed markedly in their ability to activate the respiratory burst. The peptides FMLP and C5a induced a single, strong chemiluminescence response whereas the lipids leukotriene B4 and platelet activating factor induced a markedly less intense response with a two-peak profile. Respiratory burst activation by the peptides was dependent on extracellular Ca2+ whereas the lipids required both Mg2+ and Ca2+. The results indicate that mobilization of intracellular Ca2+ is insufficient by itself to induce respiratory burst activation and that the intracellular pathways leading to activation differ depending on the nature of the stimulus.
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood*; D002634:Chemotaxis, Leukocyte; D003182:Complement C5 / Q000502:physiology*; D015936:Complement C5a; D007700:Kinetics; D007975:Leukotriene B4 / Q000494:pharmacology*; D008163:Luminescent Measurements; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011817:Rabbits; D013481:Superoxides / Q000097:blood*
chemical_list: D003182:Complement C5; D010972:Platelet Activating Factor; D013481:Superoxides; D007975:Leukotriene B4; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a; D002118:Calcium