Faculty Collaboration Database

Ventilatory long-term facilitation in unanesthetized rats. J Appl Physiol (1985) 2001 Aug;91(2):709-16

Date

07/18/2001

Pubmed ID

11457785

DOI

10.1152/jappl.2001.91.2.709

Scopus ID

2-s2.0-0034923789 (requires institutional sign-in at Scopus site)   133 Citations

Abstract

We tested the hypothesis that unanesthetized rats exhibit ventilatory long-term facilitation (LTF) after intermittent, but not continuous, hypoxia. Minute ventilation (VE) and carbon dioxide production (VCO(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 (FI(O(2))) = 0.08--0.09 and inspired CO(2) fraction (FI(CO(2))) = 0.04] or poikilocapnic (FI(O(2)) = 0.11 and FI(CO(2)) = 0.00). Sixty minutes after intermittent hypoxia, VE or VE/VCO(2) was significantly greater than baseline in both isocapnic and poikilocapnic conditions. In contrast, 60 min after continuous hypoxia, VE and VE/VCO(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.

Author List

Olson EB Jr, Bohne CJ, Dwinell MR, Podolsky A, Vidruk EH, Fuller DD, Powell FL, Mitchel GS

Author

Melinda R. Dwinell PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Carbon Dioxide
Hypoxia
Male
Partial Pressure
Plethysmography
Rats
Rats, Sprague-Dawley
Respiratory Mechanics
Tidal Volume
Time Factors