Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia.
To examine the hypothesis that the human pulmonary vascular response to hypoxia has a component with a slow time course, we measured pulmonary vascular resistance (PVR) in six healthy adult males during 8 h of isocapnic hypoxia. A balloon-tipped pulmonary artery catheter with thermistor was introduc...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
1997
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| _version_ | 1797074113433436160 |
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| author | Dorrington, K Clar, C Young, J Jonas, M Tansley, J Robbins, P |
| author_facet | Dorrington, K Clar, C Young, J Jonas, M Tansley, J Robbins, P |
| author_sort | Dorrington, K |
| collection | OXFORD |
| description | To examine the hypothesis that the human pulmonary vascular response to hypoxia has a component with a slow time course, we measured pulmonary vascular resistance (PVR) in six healthy adult males during 8 h of isocapnic hypoxia. A balloon-tipped pulmonary artery catheter with thermistor was introduced via a forearm vein and used to derive PVR. The subjects were seated in a chamber in which the oxygen and carbon dioxide concentrations were adjusted to maintain an end-tidal Po2 of 50 Torr and an end-tidal Pco2 equal to the subject's normal prehypoxic value. PVR was measured before and at 0.5-h intervals during 8 h of hypoxia, the following 3 h of isocapnic euoxia (end-tidal Po2 100 Torr), and a subsequent 1-h reexposure to hypoxia. PVR rose from 1.23 +/- 0.26 (SE) Torr-min.1(-1) under euoxia [time (t) = 0] to 1.77 +/- 0.21 Torr.min.1(-1) at t = 0.5 h, reached a maximum at 2 h (2.91 +/- 0.33 Torr.min.1(-1)), and remained fairly constant between 2 and 8 h. Restoration of euoxia at 8 h led to a reduction in PVR with a slow component. Reexposure to hypoxia at 11 h resulted in a greater increase in PVR than at 1 h. Systemic vascular resistance had a similar slow component to its response, falling from 18.6 +/- 1.3 Torr.min.1(-1) at t = 0 to 17.3 +/- 1.4 Torr.min.1(-1) at t = 0.5 h, 14.4 +/- 0.6 Torr.min.1(-1) at t = 4 h, and 13.8 +/- 0.8 Torr.min.1(-1) at t = 8 h. The human pulmonary and systemic vascular responses to hypoxia extend over at least several hours. |
| first_indexed | 2024-03-06T23:31:38Z |
| format | Journal article |
| id | oxford-uuid:6c3b9287-a0a2-40cc-9267-5523daf21b47 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:31:38Z |
| publishDate | 1997 |
| record_format | dspace |
| spelling | oxford-uuid:6c3b9287-a0a2-40cc-9267-5523daf21b472022-03-26T19:09:27ZTime course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:6c3b9287-a0a2-40cc-9267-5523daf21b47EnglishSymplectic Elements at Oxford1997Dorrington, KClar, CYoung, JJonas, MTansley, JRobbins, PTo examine the hypothesis that the human pulmonary vascular response to hypoxia has a component with a slow time course, we measured pulmonary vascular resistance (PVR) in six healthy adult males during 8 h of isocapnic hypoxia. A balloon-tipped pulmonary artery catheter with thermistor was introduced via a forearm vein and used to derive PVR. The subjects were seated in a chamber in which the oxygen and carbon dioxide concentrations were adjusted to maintain an end-tidal Po2 of 50 Torr and an end-tidal Pco2 equal to the subject's normal prehypoxic value. PVR was measured before and at 0.5-h intervals during 8 h of hypoxia, the following 3 h of isocapnic euoxia (end-tidal Po2 100 Torr), and a subsequent 1-h reexposure to hypoxia. PVR rose from 1.23 +/- 0.26 (SE) Torr-min.1(-1) under euoxia [time (t) = 0] to 1.77 +/- 0.21 Torr.min.1(-1) at t = 0.5 h, reached a maximum at 2 h (2.91 +/- 0.33 Torr.min.1(-1)), and remained fairly constant between 2 and 8 h. Restoration of euoxia at 8 h led to a reduction in PVR with a slow component. Reexposure to hypoxia at 11 h resulted in a greater increase in PVR than at 1 h. Systemic vascular resistance had a similar slow component to its response, falling from 18.6 +/- 1.3 Torr.min.1(-1) at t = 0 to 17.3 +/- 1.4 Torr.min.1(-1) at t = 0.5 h, 14.4 +/- 0.6 Torr.min.1(-1) at t = 4 h, and 13.8 +/- 0.8 Torr.min.1(-1) at t = 8 h. The human pulmonary and systemic vascular responses to hypoxia extend over at least several hours. |
| spellingShingle | Dorrington, K Clar, C Young, J Jonas, M Tansley, J Robbins, P Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title | Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title_full | Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title_fullStr | Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title_full_unstemmed | Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title_short | Time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia. |
| title_sort | time course of the human pulmonary vascular response to 8 hours of isocapnic hypoxia |
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