Characterization of receptor-mediated and store-regulated Ca2+ influx in human neutrophils
| Autor: | Antoinette Monod, Daniel Pablo Lew, Nicolas Demaurex, Karl-Heinz Krause |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Calcium/ metabolism
medicine.medical_specialty Thapsigargin Neutrophils Receptors Cell Surface/drug effects/ metabolism chemistry.chemical_element Receptors Cell Surface Manganese/metabolism Calcium Biochemistry chemistry.chemical_compound Internal medicine medicine Extracellular Humans Receptor Molecular Biology Magnesium ion Imidazoles/pharmacology ddc:616 Terpenes/pharmacology Manganese Terpenes Biological Transport/drug effects Imidazoles Biological Transport Chemotaxis Cell Biology Receptor-mediated endocytosis N-Formylmethionine Leucyl-Phenylalanine Kinetics Endocrinology chemistry Biophysics Neutrophils/drug effects/ metabolism N-Formylmethionine Leucyl-Phenylalanine/pharmacology Intracellular Research Article |
| Zdroj: | Biochemical Journal, Vol. 297 ( Pt 3) (1994) pp. 595-601 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj2970595 |
| Popis: | 1. It is not known to what extent the emptying of intracellular Ca2+ stores participates in the mediation of chemoattractant-induced Ca2+ influx in human neutrophils. To study this question, we compared the properties of bivalent-cation influx in response to the chemoattractant N-formyl-L-methionyl-L-leucyl-L-phenyl-alanine (f-MLP) and to the microsomal Ca(2+)-ATPase inhibitor thapsigargin. 2. The influx pathway activated by f-MLP and thapsigargin had identical properties of permeation. Mn2+ influx became saturated at around 1 mM extracellular Mn2+, whereas Ca2+ influx did not become saturated up to concentrations of 10 mM. 3. The influx of the two bivalent cations, Mn2+ and Ca2+, was activated to a similar extent and with identical kinetics of activation. 4. The Mn2+ influx activated by f-MLP and thapsigargin was blocked, with identical dose-inhibition curves, by four imidazole analogues. 5. The same relationship between the emptying of Ca2+ stores and bivalent-cation influx was observed for f-MLP and thapsigargin, with a half-maximal activation of the influx at 40% emptying of intracellular stores. 6. In conclusion, neutrophils possess a single type of Ca(2+)-influx pathway that is activated by receptor agonists and by store depletion. Receptor agonists activate this influx pathway to a large extent, if not completely, through the depletion of intracellular Ca2+ stores. |
| Databáze: | OpenAIRE |
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