Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Thermal drive contributes to hyperventilation during exercise in sheep

P L Entin1, D Robertshaw, R E Rawson

  • 1Department of Physiology, Cornell University, Ithaca, New York 14853, USA.

Journal of Applied Physiology (Bethesda, Md. : 1985)
|July 9, 1998
PubMed
Summary

Exercise hypocapnia in sheep is driven by rising body temperature, not exercise intensity. This study quantifies factors influencing arterial CO2 levels during exertion, revealing thermal drive as the primary cause.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Age is no barrier to muscle structural, biochemical and angiogenic adaptations to training up to 24 months in female rats.

The Journal of physiology·2005
Same author

Effect of locomotor respiratory coupling on respiratory evaporative heat loss in the sheep.

Journal of applied physiology (Bethesda, Md. : 1985)·1999
Same author

Arterial blood gas tensions during exercise in neonatal lambs.

Respiration physiology·1999
Same author

Circannual changes in free thyroxine, prolactin, testes, and relative food intake in woodchucks, Marmota monax.

The American journal of physiology·1999
Same author

Measurement of cardiac output during exercise by open-circuit acetylene uptake.

Journal of applied physiology (Bethesda, Md. : 1985)·1999
Same author

Volume of extravascular lung fluid determined by blood ultrasound velocity and electrical impedance dilution.

ASAIO journal (American Society for Artificial Internal Organs : 1992)·1998

Area of Science:

  • Exercise Physiology
  • Animal Models
  • Respiratory Regulation

Background:

  • Exercise hypocapnia, a decrease in arterial CO2 tension during exercise, has an unknown etiology.
  • Understanding factors influencing ventilation during exercise is crucial for physiological research.

Purpose of the Study:

  • To quantify the contributions of exercise intensity, lactic acid, environmental temperature, rectal temperature, and physical conditioning to arterial CO2 tension (PaCO2) variance in exercising sheep.
  • To test the hypothesis that thermal drive contributes to hyperventilation during exercise.

Main Methods:

  • Four unshorn sheep were exercised at 30%, 50%, and 70% of maximal O2 consumption.
  • Measurements included rectal temperature (Tre), O2 consumption, lactic acid, and PaCO2.

Related Experiment Videos

  • Data were analyzed using multiple regression on PaCO2, with some sheep exercised in a cold environment after shearing.

    • Main Results:

    • Rectal temperature (Tre) increased, and PaCO2 decreased during exercise, except at low intensity in the cold.
    • Rectal temperature (Tre) explained 77% of the variance in PaCO2.
    • Exercise intensity explained only 5% of the variance; other factors were insignificant.

    Conclusions:

    • Thermal drive significantly contributes to hyperventilation during exercise in sheep.
    • Body temperature is the primary determinant of PaCO2 changes during exercise in this model.
    • Exercise intensity plays a minor role in exercise hypocapnia in sheep.