{"doi":"10.1002/eji.1830170916","title":"The cytosolic free calcium in anti‐μ‐stimulated human B cells is derived partly from extracellular medium and partly from intracellular stores","abstract":"<jats:title>Abstract</jats:title><jats:p>The inositol phospholipid metabolism and the increase in cytosolic free Ca<jats:sup>2+</jats:sup> concentration ([Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub>) into the cell are recognized as two important events in the anti‐μ‐induced B cell activation. The anti‐μ stimulation caused the [<jats:sup>3</jats:sup>H]inositol incorporation and also a rapid increase in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> from 85 nM to 285 nM. This signal returned to baseline a few minutes after stimulation. By using the fluorescent indicator quin‐2 we demonstrated that this [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> uptake was derived part from extracellular medium and part from intracellular stores. Both EGTA (a calcium chelator) and TMB.8 (a drug which interferes with Ca<jats:sup>2+</jats:sup> sequestration by smooth endoplasmic retiulum) partially suppressed the intracellular Ca<jats:sup>2+</jats:sup> uptake and were fully inhibitory when added together. The role of Ca<jats:sup>2+</jats:sup> from intracellular stores may also be evidenced in calcium‐free experiments, or in permeabilized experiments using exogenous inositol 1,4,5‐trisphosphate (IP<jats:sub>3</jats:sub>, the putative mobilizer of intracellular Ca<jats:sup>2+</jats:sup>). Preventing the increase in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> also prevents the apparition of early activation markers. These results are consistent with the hypothesis that the Ca<jats:sup>2+</jats:sup> increase in B cells stimulated by anti‐μ is caused by the generation of IP<jats:sub>3</jats:sub> during the phosphatidyl‐inositol metabolism and also by the entry of extracellular Ca<jats:sup>2+</jats:sup> through the plasma membrane.</jats:p>","journal":"European Journal of Immunology","year":1987,"id":605360,"datarank":0.42498200160843247,"base_score":2.833213344056216,"endowment":2.833213344056216,"self_citation_contribution":0.42498200160843247,"citation_network_contribution":0.0,"self_endowment_contribution":0.42498200160843247,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":16,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1553543,"name":"Alphonse Calenda","orcid":null,"position":1,"is_corresponding":false},{"id":726540,"name":"Jean‐François Delfraissy","orcid":null,"position":2,"is_corresponding":false},{"id":1553546,"name":"Aimé Vazquez","orcid":null,"position":3,"is_corresponding":false},{"id":824093,"name":"Jean‐François Bach","orcid":"0000-0002-1282-6067","position":4,"is_corresponding":false},{"id":182837,"name":"Pierre Galanaud","orcid":null,"position":5,"is_corresponding":false},{"id":1553541,"name":"Bernard Dugas","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"The cytosolic free calcium in anti‐μ‐stimulated human B cells is derived partly from extracellular medium and partly from intracellular stores","abstract":"<jats:title>Abstract</jats:title><jats:p>The inositol phospholipid metabolism and the increase in cytosolic free Ca<jats:sup>2+</jats:sup> concentration ([Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub>) into the cell are recognized as two important events in the anti‐μ‐induced B cell activation. The anti‐μ stimulation caused the [<jats:sup>3</jats:sup>H]inositol incorporation and also a rapid increase in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> from 85 nM to 285 nM. This signal returned to baseline a few minutes after stimulation. By using the fluorescent indicator quin‐2 we demonstrated that this [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> uptake was derived part from extracellular medium and part from intracellular stores. Both EGTA (a calcium chelator) and TMB.8 (a drug which interferes with Ca<jats:sup>2+</jats:sup> sequestration by smooth endoplasmic retiulum) partially suppressed the intracellular Ca<jats:sup>2+</jats:sup> uptake and were fully inhibitory when added together. The role of Ca<jats:sup>2+</jats:sup> from intracellular stores may also be evidenced in calcium‐free experiments, or in permeabilized experiments using exogenous inositol 1,4,5‐trisphosphate (IP<jats:sub>3</jats:sub>, the putative mobilizer of intracellular Ca<jats:sup>2+</jats:sup>). Preventing the increase in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> also prevents the apparition of early activation markers. These results are consistent with the hypothesis that the Ca<jats:sup>2+</jats:sup> increase in B cells stimulated by anti‐μ is caused by the generation of IP<jats:sub>3</jats:sub> during the phosphatidyl‐inositol metabolism and also by the entry of extracellular Ca<jats:sup>2+</jats:sup> through the plasma membrane.</jats:p>","is_dataset_classified":null,"base_score":2.833213344056216,"endowment":2.833213344056216,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"2820750","pmcid":null,"openalex_id":"https://openalex.org/W2163812620","authors":[],"funders":[],"total_grants":0,"fwci":0.5384,"citation_percentile":0.67385496,"influential_citations":0,"citation_trend":[{"year":2013,"count":2},{"year":2016,"count":1},{"year":2017,"count":1}],"oa_status":"closed","license":"http://onlinelibrary.wiley.com/termsAndConditions#vor","oa_locations":[{"url":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Feji.1830170916","host_type":"publisher"},{"url":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/eji.1830170916","host_type":"publisher"},{"url":"https://doi.org/10.1002/eji.1830170916","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/2820750","host_type":"repository"}],"fields_of_study":["T-cell and B-cell Immunology","Protein Kinase Regulation and GTPase Signaling","Pancreatic function and diabetes"],"mesh_terms":["Antibodies, Anti-Idiotypic","Antibodies, Monoclonal","B-Lymphocytes","Biological Transport","Calcium","Cytosol","Extracellular Space","Humans","Immunoglobulin M","Intracellular Fluid","Lymphocyte Activation","Phosphatidylinositols"],"keywords":["Extracellular","Intracellular","Inositol","EGTA","Cytosol","Endoplasmic reticulum","Biology","Calcium","Stimulation","Inositol phosphate","Fura-2","Cell biology","Calcium in biology","Biochemistry","Biophysics","Inositol trisphosphate","Plasma membrane Ca2+ ATPase","Endocrinology","Internal medicine","Receptor","ATPase","Enzyme"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Clean water and sanitation"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-07-30T02:15:41.059682Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}