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Development of pulmonary vascular response to oxygen
- Source :
- American Journal of Physiology-Heart and Circulatory Physiology. 254:H542-H546
- Publication Year :
- 1988
- Publisher :
- American Physiological Society, 1988.
-
Abstract
- The ability of the pulmonary circulation of the fetal lamb to respond to a rise in oxygen tension was studied from 94 to 146 days of gestation. The unanesthetized ewe breathed room air at normal atmospheric pressure, followed by 100% oxygen at three atmospheres absolute pressure in a hyperbaric chamber. In eleven near-term lambs (132 to 146 days of gestation), fetal arterial oxygen tension (PaO2) increased from 25 +/- 1 to 55 +/- 6 Torr (mean +/- SE), which increased the proportion of right ventricular output distributed to the fetal lungs from 8 +/- 1 to 59 +/- 5%. In five very immature lambs (94 to 101 days of gestation), fetal PaO2 increased from 27 +/- 1 to 174 +/- 70 Torr, but the proportion of right ventricular output distributed to the lung did not change, 8 +/- 1 to 9 +/- 1%. In five of the near-term lambs, pulmonary blood flow was measured. It increased from 34 +/- 3 to 298 +/- 35 ml.kg fetal wt-1.min-1, an 8.8-fold increase. We conclude that the pulmonary circulation of the fetal lamb does not respond to an increase in oxygen tension before 101 days of gestation; however, near term an increase in oxygen tension alone can induce the entire increase in pulmonary blood flow that normally occurs after the onset of breathing at birth.
- Subjects :
- Pulmonary Circulation
medicine.medical_specialty
Physiology
Partial Pressure
chemistry.chemical_element
Oxygen
Fetus
Pregnancy
Physiology (medical)
Internal medicine
medicine
Animals
Respiratory system
Lung
Hyperbaric Oxygenation
Sheep
Chemistry
business.industry
Oxygen tension
Blood pressure
medicine.anatomical_structure
Blood Circulation
Circulatory system
Cardiology
Female
Cardiology and Cardiovascular Medicine
Nuclear medicine
business
Blood vessel
Subjects
Details
- ISSN :
- 15221539 and 03636135
- Volume :
- 254
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Heart and Circulatory Physiology
- Accession number :
- edsair.doi.dedup.....5fad4b729b54662ed822598dfb53c2ce