Changes in inositol 1,4,5-trisphosphate mass in agonist-stimulated human neutrophils.
Changes in the endogenous synthesis of inositol 1,4,5-trisphosphate (IP3) mass have been quantitated in human peripheral neutrophils stimulated with FMLP, LTB4 and PAF using a recently described, highly specific radioreceptor assay. Each agonist induced a concentration-dependent synthesis of IP3 which was detectable within 10 seconds after stimulation. IP3 production was short-lived, returning to basal levels within 90 seconds. The maximal stimulated level of IP3 in response to FMLP and LTB4 was 30-50 50 pmoles/10(7) neutrophils. PAF was more effective (approximately 100 pmoles IP3/10(7) neutrophils). The response to FMLP was inhibited by pertussis toxin, but was unaffected by cholera toxin. Pretreatment with cytochalasin B did not enhance IP3 synthesis. These findings are generally consistent with previous studies employing [3H]myo-inositol-prelabeled cells, and provide one of the first measurements of IP3 synthesis by mass in agonist-stimulated human neutrophils.
Fruman
D A
DA
Institute of Biological Sciences, Syntex Research, Palo Alto, CA 94303.
Gamache
D A
DA
Ernest
M J
MJ
D015220:Calcium Channels; D002772:Cholera Toxin / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007975:Leukotriene B4 / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D010972:Platelet Activating Factor / Q000494:pharmacology; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear; D016897:Respiratory Burst / Q000187:drug effects; D013268:Stimulation, Chemical; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010972:Platelet Activating Factor; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D010566:Virulence Factors, Bordetella; D007975:Leukotriene B4; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015544:Inositol 1,4,5-Trisphosphate; D002772:Cholera Toxin; D037342:Pertussis Toxin