{"doi":"10.1111/micc.12699","title":"Evidence for role of capillaries in regulation of skeletal muscle oxygen supply","abstract":"Abstract How oxygen (O 2 ) supply to capillaries is regulated to match the tissue's demand is unknown. Erythrocytes have been proposed as sensors in this regulatory mechanism since they release ATP, a vasodilator, in an oxygen saturation (SO 2 )‐dependent manner. ATP causes hyperpolarization of endothelial cells resulting in conducted vasodilation to arterioles. Objective We propose individual capillary units can regulate their own O 2 supply by direct communication to upstream arterioles via electrically coupled endothelium. Methods To test this hypothesis, we developed a transparent micro‐exchange device for localized O 2 exchange with surface capillaries of intact tissue. The device was fabricated with an O 2 permeable micro‐outlet 0.2 × 1.0 mm. Experiments were performed on rat extensor digitorum longus (EDL) muscle using dual wavelength video microscopy to measure capillary hemodynamics and erythrocyte SO 2 . Responses to local O 2 perturbations were measured with only capillaries positioned over the micro‐outlet. Results Step changes in the gas mixture %O 2 caused physiological changes in erythrocyte SO 2 , and appropriate changes in flow to offset the O 2 challenge if at least 3–4 capillaries were stimulated. Conclusion These results support our hypothesis that individual capillary units play a role in regulating their erythrocyte supply in response to a changing O 2 environment.","journal":"Microcirculation","year":2021,"id":189887,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":14,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9529,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":753294,"name":"Graham Fraser","orcid":"0000-0002-5733-201X","position":1,"is_corresponding":false},{"id":278401,"name":"Daniel Goldman","orcid":"0000-0002-8707-5536","position":2,"is_corresponding":false},{"id":753295,"name":"Stephanie Milkovich","orcid":"0009-0002-8813-2085","position":3,"is_corresponding":false},{"id":753296,"name":"Jun Yang","orcid":"0000-0002-7545-4213","position":4,"is_corresponding":false},{"id":753297,"name":"Christopher G. Ellis","orcid":"0000-0002-7760-1846","position":5,"is_corresponding":false},{"id":754020,"name":"Nour Ghonaim","orcid":null,"position":0,"is_corresponding":true}],"reference_count":72,"raw_metadata":null,"created_at":"2026-07-18T23:49:22.671571Z","pmid":"33853202","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":[]}