Document Detail

Lack of long-term facilitation of ventilation after exposure to hypoxia in goats.
MedLine Citation:
PMID:  9178372     Owner:  NLM     Status:  MEDLINE    
Episodic hypoxia has been shown to induce augmented normoxic ventilatory drive or long-term facilitation (LTF, continued hyperventilation after termination of hypoxic stimulation) in awake dogs and awake goats. The main objective of these experiments was to examine whether continuous isocapnic hypoxia in awake goats elicits LTF and additionally, to determine if goats exhibit hypoxic ventilatory decline (roll-off) during the hypoxic exposure. Goats were exposed to either 4 h of isocapnic hypoxia (n = 10) or 30 min of isocapnic hypoxia (n = 7). Ventilation (VE), tidal volume and frequency were measured before, during and following the end of the isocapnic hypoxia (PaO2 40 Torr) exposure. During the 4 h period of hypoxia, VE increased in a time-dependent manner in a typical pattern of acclimatization, reaching a mean of 40.8 +/- 3.6 L/min at the end of 4 h. Five minutes after return to normoxia, VE was 13.0 +/- 0.8 L/min, not different than control VE (13.1 +/- 0.9 L/min) measured prior to the hypoxic exposure and remained unchanged from this value for another 30 min. During the 30 min hypoxic exposure, VE increased upon exposure to hypoxia, remained significantly elevated throughout the hypoxic exposure, but promptly returned to control levels upon return to normoxia. These results indicate that continuous isocapnic hypoxia elicits neither long term facilitation of ventilation nor hypoxic ventilatory decline in awake goats.
M R Dwinell; P L Janssen; G E Bisgard
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Respiration physiology     Volume:  108     ISSN:  0034-5687     ISO Abbreviation:  Respir Physiol     Publication Date:  1997 Apr 
Date Detail:
Created Date:  1997-07-30     Completed Date:  1997-07-30     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0047142     Medline TA:  Respir Physiol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  1-9     Citation Subset:  IM; S    
Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Anoxia / physiopathology*
Goats / physiology*
Long-Term Potentiation / physiology*
Oxygen Consumption / physiology
Pulmonary Ventilation / physiology*
Time Factors
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Metabolism of tacrolimus (FK 506) in rat liver microsomes. Effect of rifampin and dexamethasone.
Next Document:  Passive constriction of the upper airway during central apneas: fiberoptic and EMG investigations.