Thermal drive contributes to hyperventilation during exercise in sheep

Pauline L Entin, David Robertshaw, Richard E. Rawson

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (T(re)), and physical conditioning to the variance in arterial CO2 tension (Pa(CO2)) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at ~30, 50, and 70% of maximal O2 consumption for 30 min, or until exhaustion, both before and after 5 wk of physical conditioning. In addition, two of the sheep were shorn and exercised at each intensity in a cold (<15°C) environment. Tre and O2 consumption were measured continuously. Lactic acid and Pa(CO2) were measured at 5- to 10- min intervals. Data were analyzed by multiple regression on Pa(CO2). During exercise, T(re) rose and Pa(CO2) fell, except at the lowest ExInt in the cold environment. T(re) explained 77% of the variance in Pa(CO2), and ExInt explained 5%. All other variables were insignificant. We conclude that, in sheep, thermal drive contributes to hyperventilation during exercise.

Original languageEnglish (US)
Pages (from-to)318-325
Number of pages8
JournalJournal of Applied Physiology
Volume85
Issue number1
StatePublished - 1998
Externally publishedYes

Fingerprint

Hyperventilation
Sheep
Hot Temperature
Temperature
Lactic Acid
Hypocapnia
Arterial Pressure

Keywords

  • Blood gases
  • Hyperthermia
  • Hypocapnia
  • Respiratory alkalosis
  • Respiratory control
  • Thermoregulation

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Thermal drive contributes to hyperventilation during exercise in sheep. / Entin, Pauline L; Robertshaw, David; Rawson, Richard E.

In: Journal of Applied Physiology, Vol. 85, No. 1, 1998, p. 318-325.

Research output: Contribution to journalArticle

Entin, Pauline L ; Robertshaw, David ; Rawson, Richard E. / Thermal drive contributes to hyperventilation during exercise in sheep. In: Journal of Applied Physiology. 1998 ; Vol. 85, No. 1. pp. 318-325.
@article{0bea5e2cd4df46d498e6a22dfe6f5348,
title = "Thermal drive contributes to hyperventilation during exercise in sheep",
abstract = "The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (T(re)), and physical conditioning to the variance in arterial CO2 tension (Pa(CO2)) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at ~30, 50, and 70{\%} of maximal O2 consumption for 30 min, or until exhaustion, both before and after 5 wk of physical conditioning. In addition, two of the sheep were shorn and exercised at each intensity in a cold (<15°C) environment. Tre and O2 consumption were measured continuously. Lactic acid and Pa(CO2) were measured at 5- to 10- min intervals. Data were analyzed by multiple regression on Pa(CO2). During exercise, T(re) rose and Pa(CO2) fell, except at the lowest ExInt in the cold environment. T(re) explained 77{\%} of the variance in Pa(CO2), and ExInt explained 5{\%}. All other variables were insignificant. We conclude that, in sheep, thermal drive contributes to hyperventilation during exercise.",
keywords = "Blood gases, Hyperthermia, Hypocapnia, Respiratory alkalosis, Respiratory control, Thermoregulation",
author = "Entin, {Pauline L} and David Robertshaw and Rawson, {Richard E.}",
year = "1998",
language = "English (US)",
volume = "85",
pages = "318--325",
journal = "Journal of Applied Physiology Respiratory Environmental and Exercise Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Thermal drive contributes to hyperventilation during exercise in sheep

AU - Entin, Pauline L

AU - Robertshaw, David

AU - Rawson, Richard E.

PY - 1998

Y1 - 1998

N2 - The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (T(re)), and physical conditioning to the variance in arterial CO2 tension (Pa(CO2)) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at ~30, 50, and 70% of maximal O2 consumption for 30 min, or until exhaustion, both before and after 5 wk of physical conditioning. In addition, two of the sheep were shorn and exercised at each intensity in a cold (<15°C) environment. Tre and O2 consumption were measured continuously. Lactic acid and Pa(CO2) were measured at 5- to 10- min intervals. Data were analyzed by multiple regression on Pa(CO2). During exercise, T(re) rose and Pa(CO2) fell, except at the lowest ExInt in the cold environment. T(re) explained 77% of the variance in Pa(CO2), and ExInt explained 5%. All other variables were insignificant. We conclude that, in sheep, thermal drive contributes to hyperventilation during exercise.

AB - The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (T(re)), and physical conditioning to the variance in arterial CO2 tension (Pa(CO2)) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at ~30, 50, and 70% of maximal O2 consumption for 30 min, or until exhaustion, both before and after 5 wk of physical conditioning. In addition, two of the sheep were shorn and exercised at each intensity in a cold (<15°C) environment. Tre and O2 consumption were measured continuously. Lactic acid and Pa(CO2) were measured at 5- to 10- min intervals. Data were analyzed by multiple regression on Pa(CO2). During exercise, T(re) rose and Pa(CO2) fell, except at the lowest ExInt in the cold environment. T(re) explained 77% of the variance in Pa(CO2), and ExInt explained 5%. All other variables were insignificant. We conclude that, in sheep, thermal drive contributes to hyperventilation during exercise.

KW - Blood gases

KW - Hyperthermia

KW - Hypocapnia

KW - Respiratory alkalosis

KW - Respiratory control

KW - Thermoregulation

UR - http://www.scopus.com/inward/record.url?scp=0031827562&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031827562&partnerID=8YFLogxK

M3 - Article

C2 - 9655792

AN - SCOPUS:0031827562

VL - 85

SP - 318

EP - 325

JO - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

JF - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

SN - 8750-7587

IS - 1

ER -