Document Detail

Mechanism of hyperpnea induced by changes in pulmonary blood flow.
MedLine Citation:
PMID:  6427155     Owner:  NLM     Status:  MEDLINE    
Increases in pulmonary blood flow can elicit hyperpnea. To examine the mechanisms responsible, we surgically isolated the systemic and pulmonary circulations in six dogs and independently controlled PCO2, PO2, and blood flow in each circuit. Anesthesia was induced with ketamine and maintained with halothane. Systemic venous return was drained from the right atrium and passed through a membrane oxygenator and heat exchanger; blood was returned to the ascending aorta (Qs). An identical bypass was established for the pulmonary circulation, draining blood from the left atrium and returning it to the pulmonary artery (Qp). The lungs were initially ventilated with room air. Qs and systemic arterial CO2 gas tension were maintained at approximately 0.080 1 X min-1 X kg-1 and 40 Torr, respectively. Pulmonary arterial CO2 gas tension was set near 55 Torr, and Qp varied. Ventilatory drive was assessed by minute integration (MI) of the activity recorded from the central end of the left C5 root of the phrenic nerve. MI increased as much as 160% above control as Qp was increased over the range of 0.025 (control) to 0.175 1 X min-1 X kg-1. When pulmonary CO2 gradients were eliminated by a rebreathing technique, MI was independent of Qp. These results suggest that CO2-sensitive pulmonary receptors respond to the change in pulmonary PCO2 gradients which occur when Qp is elevated (breathing room air) augmenting ventilation.
J F Green; N D Schmidt
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology: respiratory, environmental and exercise physiology     Volume:  56     ISSN:  0161-7567     ISO Abbreviation:  J Appl Physiol Respir Environ Exerc Physiol     Publication Date:  1984 May 
Date Detail:
Created Date:  1984-07-16     Completed Date:  1984-07-16     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  7801242     Medline TA:  J Appl Physiol Respir Environ Exerc Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1418-22     Citation Subset:  IM; S    
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MeSH Terms
Carbon Dioxide / blood*
Chemoreceptor Cells / physiology
Lung / innervation
Oxygen / blood
Phrenic Nerve / physiology
Pulmonary Circulation*
Pulmonary Gas Exchange
Vagus Nerve / physiology
Grant Support
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

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