{"doi":"10.1016/j.bbabio.2025.149568","title":"Chamber oxygen concentration impacts mitochondrial function and hydrogen peroxide appearance in permeabilized human skeletal muscle fibers","abstract":"Skeletal muscle mitochondrial respiration is commonly assessed ex vivo using permeabilized fibers in media with high oxygen (O 2 ) concentrations to ensure that O 2 availability does not limit respiration. However, high O 2 concentrations also increase the production of reactive O 2 species that can negatively affect respiration. In this study, we tested the hypotheses that permeabilized fiber mitochondria in a high, compared to low, O 2 concentration would (i) not be different at maximal state 3 respiration rate (V max ), (ii) have lower submaximal respiration rates at submaximal O 2 concentrations, and (iii) have greater total cumulative hydrogen peroxide (H 2 O 2 ) appearance. We continuously monitored mitochondrial state 3 respiration and H 2 O 2 appearance rates using high-resolution respirometry in permeabilized skeletal muscle fibers (12 untrained participants; 22 ± 4 yrs) with either control (~127 mmHg; CON) or high (~327 mmHg; HIGH) partial pressures of O 2 (PO 2 ). V max was not different between conditions (HIGH: 80.7 ± 16.7 vs. CON: 82.3 ± 18.7 pmol/s/mg, p = 0.695). The PO 2 at 80 % V max (P 80 ) was greater in HIGH (73.9 ± 25.5 vs. 28.0 ± 7.1 mmHg, p < 0.001) and respiration rates at 5–60 mmHg PO 2 were lower for HIGH than CON (all p < 0.001). Additionally, the total cumulative H 2 O 2 appearance was greater in HIGH than CON ( n = 11; 51.5 ± 23.2 vs. 18.3 ± 10.3 pmol/mg, p < 0.001), and this difference was directly correlated with the difference in P 80 ( r = 0.655, p = 0.029). The current findings support that a high O 2 concentration, by itself, does not appear to affect V max in the permeabilized skeletal muscle fiber preparation, but the corollary increase in H 2 O 2 exposure may diminish mitochondrial state 3 respiratory function.","journal":"Biochimica et Biophysica Acta (BBA) - Bioenergetics","year":2025,"id":545945,"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":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9569,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":447420,"name":"Soung Hun Park","orcid":"0000-0002-1423-0929","position":1,"is_corresponding":false},{"id":444284,"name":"Jesse C. Craig","orcid":"0000-0001-5959-4139","position":2,"is_corresponding":false},{"id":535453,"name":"Matthew T. Lewis","orcid":"0000-0003-0580-6866","position":3,"is_corresponding":false},{"id":369096,"name":"Joel D. Trinity","orcid":"0000-0001-8271-6536","position":4,"is_corresponding":false},{"id":369097,"name":"Russell S. Richardson","orcid":"0000-0003-0233-5923","position":5,"is_corresponding":false},{"id":404397,"name":"Ryan M. Broxterman","orcid":"0000-0002-7388-2214","position":6,"is_corresponding":false},{"id":878733,"name":"Bradley A. Ruple","orcid":"0009-0001-7277-0771","position":0,"is_corresponding":true}],"reference_count":44,"raw_metadata":null,"created_at":"2026-07-19T02:53:27.751050Z","pmid":"40803624","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":[]}