Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans.
The ventilatory sensitivity to CO2, in hyperoxia, is increased after an 8-h exposure to hypoxia. The purpose of the present study was to determine whether this increase arises through an increase in peripheral or central chemosensitivity. Ten healthy volunteers each underwent 8-h exposures to 1) iso...
| Główni autorzy: | , |
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| Format: | Journal article |
| Język: | English |
| Wydane: |
2001
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| _version_ | 1826295478475554816 |
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| author | Fatemian, M Robbins, P |
| author_facet | Fatemian, M Robbins, P |
| author_sort | Fatemian, M |
| collection | OXFORD |
| description | The ventilatory sensitivity to CO2, in hyperoxia, is increased after an 8-h exposure to hypoxia. The purpose of the present study was to determine whether this increase arises through an increase in peripheral or central chemosensitivity. Ten healthy volunteers each underwent 8-h exposures to 1) isocapnic hypoxia, with end-tidal PO2 (PET(O2)) = 55 Torr and end-tidal PCO2 (PET(CO2)) = eucapnia; 2) poikilocapnic hypoxia, with PET(O2) = 55 Torr and PET(CO2) = uncontrolled; and 3) air-breathing control. The ventilatory response to CO2 was measured before and after each exposure with the use of a multifrequency binary sequence with two levels of PET(CO2): 1.5 and 10 Torr above the normal resting value. PET(O2) was held at 250 Torr. The peripheral (Gp) and the central (Gc) sensitivities were calculated by fitting the ventilatory data to a two-compartment model. There were increases in combined Gp + Gc (26%, P < 0.05), Gp (33%, P < 0.01), and Gc (23%, P = not significant) after exposure to hypoxia. There were no significant differences between isocapnic and poikilocapnic hypoxia. We conclude that sustained hypoxia induces a significant increase in chemosensitivity to CO2 within the peripheral chemoreflex. |
| first_indexed | 2024-03-07T04:01:39Z |
| format | Journal article |
| id | oxford-uuid:c4c6265a-bedd-4304-9135-b99d2050514b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:01:39Z |
| publishDate | 2001 |
| record_format | dspace |
| spelling | oxford-uuid:c4c6265a-bedd-4304-9135-b99d2050514b2022-03-27T06:26:05ZSelected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c4c6265a-bedd-4304-9135-b99d2050514bEnglishSymplectic Elements at Oxford2001Fatemian, MRobbins, PThe ventilatory sensitivity to CO2, in hyperoxia, is increased after an 8-h exposure to hypoxia. The purpose of the present study was to determine whether this increase arises through an increase in peripheral or central chemosensitivity. Ten healthy volunteers each underwent 8-h exposures to 1) isocapnic hypoxia, with end-tidal PO2 (PET(O2)) = 55 Torr and end-tidal PCO2 (PET(CO2)) = eucapnia; 2) poikilocapnic hypoxia, with PET(O2) = 55 Torr and PET(CO2) = uncontrolled; and 3) air-breathing control. The ventilatory response to CO2 was measured before and after each exposure with the use of a multifrequency binary sequence with two levels of PET(CO2): 1.5 and 10 Torr above the normal resting value. PET(O2) was held at 250 Torr. The peripheral (Gp) and the central (Gc) sensitivities were calculated by fitting the ventilatory data to a two-compartment model. There were increases in combined Gp + Gc (26%, P < 0.05), Gp (33%, P < 0.01), and Gc (23%, P = not significant) after exposure to hypoxia. There were no significant differences between isocapnic and poikilocapnic hypoxia. We conclude that sustained hypoxia induces a significant increase in chemosensitivity to CO2 within the peripheral chemoreflex. |
| spellingShingle | Fatemian, M Robbins, P Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title | Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title_full | Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title_fullStr | Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title_full_unstemmed | Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title_short | Selected contribution: chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans. |
| title_sort | selected contribution chemoreflex responses to co2 before and after an 8 h exposure to hypoxia in humans |
| work_keys_str_mv | AT fatemianm selectedcontributionchemoreflexresponsestoco2beforeandafteran8hexposuretohypoxiainhumans AT robbinsp selectedcontributionchemoreflexresponsestoco2beforeandafteran8hexposuretohypoxiainhumans |