Ventilatory response in the fetal lamb following peripheral chemodenervation
Autor: | W. A. Hodson, J. H. Murphy, D. A. Belenky, David E Woodrum, Thomas A. Standaert, C R Parks |
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Rok vydání: | 1977 |
Předmět: |
Chemoreceptor
Physiology Peripheral chemoreceptors chemistry.chemical_compound Physiology (medical) medicine Animals Lung Sodium cyanide Denervation Carotid Body Fetus Cyanides Sheep business.industry Respiration Carbon Dioxide Hydrogen-Ion Concentration Hypoxia (medical) Delivery Obstetric Peripheral Oxygen chemistry Anesthesia Breathing medicine.symptom business |
Zdroj: | Journal of Applied Physiology. 42:630-635 |
ISSN: | 1522-1601 8750-7587 |
Popis: | Carotid infusions of sodium cyanide solution and perfusions of hypoxemic or hypercapnic fetal blood were done before and after peripheral chemoreceptor denervation. Step changes in PaO2 ranged from -11 to -22 Torr; step changes in PaCO2 ranged from +17 to +42 Torr. The cyanide dose was 0.2 mg/kg per loop system. Control perfusions consisted of 25 ml of fetal blood without changes in pH and blood gases. A ventilatory response occurred in the majority of all experimental perfusions regardless of innervation status of the peripheral chemoreceptors. No response occurred with control perfusions. There was a marked variability in the time of onset of ventilatory activity with a delay of greater than 10 s occurring following most perfusions. These studies demonstrate that the fetus has an attenuated ventilatory response to chemical stimuli and that hypoxia stimulates ventilation in the absence of peripheral chemoreceptors. |
Databáze: | OpenAIRE |
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