Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Ventilatory long-term facilitation in unanesthetized rats

Ventilatory long-term facilitation in unanesthetized rats Abstract We tested the hypothesis that unanesthetized rats exhibit ventilatory long-term facilitation (LTF) after intermittent, but not continuous, hypoxia. Minute ventilation (V˙ e ) and carbon dioxide production (V˙ co 2 ) were measured in unanesthetized, unrestrained male Sprague-Dawley rats via barometric plethysmography before, during, and after exposure to continuous or intermittent hypoxia. Hypoxia was either isocapnic inspired O 2 fraction (F i O 2 ) = 0.08–0.09 and inspired CO 2 fraction (F i CO 2 ) = 0.04 or poikilocapnic (F i O 2 = 0.11 and F i CO 2 = 0.00). Sixty minutes after intermittent hypoxia, V˙ e orV˙ e /V˙ co 2 was significantly greater than baseline in both isocapnic and poikilocapnic conditions. In contrast, 60 min after continuous hypoxia,V˙ e andV˙ e /V˙ co 2 were not significantly different from baseline values. These data demonstrate ventilatory LTF after intermittent hypoxia in unanesthetized rats. Ventilatory LTF appeared similar in its magnitude (after accounting for CO 2 feedback), time course, and dependence on intermittent hypoxia to phrenic LTF previously observed in anesthetized, vagotomized, paralyzed rats. ventilation plasticity intermittent hypoxia hypoxia respiratory control Footnotes Address for reprint requests and other correspondence: E. B. Olson, Jr., The John Rankin Laboratory of Pulmonary Medicine, Dept. of Preventive Medicine, Univ. of Wisconsin School of Medicine, 504 N. Walnut St., Madison, WI 53705-2368 (E-mail: ebolson@facstaff.wisc.edu ). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Copyright © 2001 the American Physiological Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Applied Physiology The American Physiological Society

Ventilatory long-term facilitation in unanesthetized rats

Download PDF
9 pages

Loading next page...
 
/lp/the-american-physiological-society/ventilatory-long-term-facilitation-in-unanesthetized-rats-72w5jkZl00

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
The American Physiological Society
Copyright
Copyright © 2011 the American Physiological Society
ISSN
8750-7587
eISSN
1522-1601
Publisher site
See Article on Publisher Site

Abstract

Abstract We tested the hypothesis that unanesthetized rats exhibit ventilatory long-term facilitation (LTF) after intermittent, but not continuous, hypoxia. Minute ventilation (V˙ e ) and carbon dioxide production (V˙ co 2 ) were measured in unanesthetized, unrestrained male Sprague-Dawley rats via barometric plethysmography before, during, and after exposure to continuous or intermittent hypoxia. Hypoxia was either isocapnic inspired O 2 fraction (F i O 2 ) = 0.08–0.09 and inspired CO 2 fraction (F i CO 2 ) = 0.04 or poikilocapnic (F i O 2 = 0.11 and F i CO 2 = 0.00). Sixty minutes after intermittent hypoxia, V˙ e orV˙ e /V˙ co 2 was significantly greater than baseline in both isocapnic and poikilocapnic conditions. In contrast, 60 min after continuous hypoxia,V˙ e andV˙ e /V˙ co 2 were not significantly different from baseline values. These data demonstrate ventilatory LTF after intermittent hypoxia in unanesthetized rats. Ventilatory LTF appeared similar in its magnitude (after accounting for CO 2 feedback), time course, and dependence on intermittent hypoxia to phrenic LTF previously observed in anesthetized, vagotomized, paralyzed rats. ventilation plasticity intermittent hypoxia hypoxia respiratory control Footnotes Address for reprint requests and other correspondence: E. B. Olson, Jr., The John Rankin Laboratory of Pulmonary Medicine, Dept. of Preventive Medicine, Univ. of Wisconsin School of Medicine, 504 N. Walnut St., Madison, WI 53705-2368 (E-mail: ebolson@facstaff.wisc.edu ). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Copyright © 2001 the American Physiological Society

Journal

Journal of Applied Physiology – The American Physiological Society

Published: Aug 1, 2001

There are no references for this article.