biostudies-literatureMao QMEXT | Japan Society for the Promotion of ScienceAgence Nationale de la Recherche425https://www.ebi.ac.uk/biostudies/studies/S-EPMC8007703biostudies-literatureUnknown4(1)Carbon monoxide (CO) is a gaseous molecule known as the silent killer. It is widely believed that an increase in blood carboxyhemoglobin (CO-Hb) is the best biomarker to define CO intoxication, while the fact that CO accumulation in tissues is the most likely direct cause of mortality is less investigated. There is no reliable method other than gas chromatography to accurately determine CO content in tissues. Here we report the properties and usage of hemoCD1, a synthetic supramolecular compound composed of an iron(II)porphyrin and a cyclodextrin dimer, as an accessible reagent for a simple colorimetric assay to quantify CO in biological samples. The assay was validated in various organ tissues collected from rats under normal conditions and after exposure to CO. The kinetic profile of CO Communications biologySensitive quantification of carbon monoxide in vivo reveals a protective role of circulating hemoglobin in CO intoxication.PMC8007703JP19K22260JP15H02569ANR-19-CE18-003201SWEET-COJP18KK0156JP19K22972JP17H02208Mizobata SMao QKitagishi HMotterlini RKawaguchi ATForesti RfalseSensitive quantification of carbon monoxide in vivo reveals a protective role of circulating hemoglobin in CO intoxication.Carbon monoxide (CO) is a gaseous molecule known as the silent killer. It is widely believed that an increase in blood carboxyhemoglobin (CO-Hb) is the best biomarker to define CO intoxication, while the fact that CO accumulation in tissues is the most likely direct cause of mortality is less investigated. There is no reliable method other than gas chromatography to accurately determine CO content in tissues. Here we report the properties and usage of hemoCD1, a synthetic supramolecular compound composed of an iron(II)porphyrin and a cyclodextrin dimer, as an accessible reagent for a simple colorimetric assay to quantify CO in biological samples. The assay was validated in various organ tissues collected from rats under normal conditions and after exposure to CO. The kinetic profile of CO 2021-01-01T00:00:00Z2021 Mar2026-04-29T00:03:43.702Z2022-02-09T15:58:52.211ZS-EPMC80077033378253410.1038/s42003-021-01880-1