Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1988 Dec;406:331–344. doi: 10.1113/jphysiol.1988.sp017383

Effects of tracheostomy breathing on brain and body temperatures in hyperthermic sheep.

H P Laburn 1, D Mitchell 1, G Mitchell 1, K Saffy 1
PMCID: PMC1191102  PMID: 3254414

Abstract

1. We measured rectal and hypothalamic temperature in sheep breathing nasally and via a tracheostomy, during hyperthermia resulting from exposure to a hot environment, exercise and fever. 2. In normothermic and hyperthermic sheep hypothalamic temperature was up to 1.0 degree C lower than rectal temperature when the sheep breathed nasally. Tracheostomy breathing abolished the rectal-hypothalamic temperature difference. 3. In sheep breathing via the tracheostomy and exposed to a dry-bulb temperature of 45-50 degrees C for 2 h, hypothalamic temperature exceeded rectal temperature by about 0.4 degrees C, and was significantly higher than that in sheep breathing nasally in the same environment. 4. During exercise on a treadmill and in the post-exercise period, the difference between hypothalamic and rectal temperature was abolished in the sheep while breathing through the tracheostomy, and rectal temperature rose to higher levels compared to those evident in the same activity while breathing nasally. 5. After an I.V. injection of 0.4 micrograms/kg lipopolysaccharide (LPS), the difference between hypothalamic and rectal temperature again was abolished in the sheep when breathing through the tracheostomy, but rectal temperature rose significantly less compared to when breathing nasally. 6. Our results indicate that selective brain cooling depends on upper respiratory tract cooling in normo- and hyperthermic states in sheep.

Full text

PDF
331

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ANDERSSON B., GRANT R., LARSSON S. Central control of heat loss mechanisms in the goat. Acta Physiol Scand. 1956 Sep 26;37(2-3):261–280. doi: 10.1111/j.1748-1716.1956.tb01362.x. [DOI] [PubMed] [Google Scholar]
  2. BLIGH J. THE RECEPTORS CONCERNED IN THE RESPIRATORY RESPONSE TO HUMIDITY IN SHEEP AT HIGH AMBIENT TEMPERATURE. J Physiol. 1963 Oct;168:747–763. doi: 10.1113/jphysiol.1963.sp007220. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Baker M. A. Brain cooling in endotherms in heat and exercise. Annu Rev Physiol. 1982;44:85–96. doi: 10.1146/annurev.ph.44.030182.000505. [DOI] [PubMed] [Google Scholar]
  4. Baker M. A., Chapman L. W., Nathanson M. Control of brain temperature in dogs: effects of tracheostomy. Respir Physiol. 1974 Dec;22(3):325–333. doi: 10.1016/0034-5687(74)90081-4. [DOI] [PubMed] [Google Scholar]
  5. Baker M. A., Hayward J. N. Carotid rete and brain temperature of cat. Nature. 1967 Oct 14;216(5111):139–141. doi: 10.1038/216139a0. [DOI] [PubMed] [Google Scholar]
  6. Baker M. A., Hayward J. N. Intracranial heat exchange and regulation of brain temperature in sheep. Life Sci. 1968 Apr 1;7(7):349–357. doi: 10.1016/0024-3205(68)90003-9. [DOI] [PubMed] [Google Scholar]
  7. Baker M. A., Hayward J. N. The influence of the nasal mucosa and the carotid rete upon hypothalamic temperature in sheep. J Physiol. 1968 Oct;198(3):561–579. doi: 10.1113/jphysiol.1968.sp008626. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Baker M. A. Influence of the carotid rete on brain temperature in cats exposed to hot environments. J Physiol. 1972 Feb;220(3):711–728. doi: 10.1113/jphysiol.1972.sp009731. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cabanac M., Caputa M. Natural selective cooling of the human brain: evidence of its occurrence and magnitude. J Physiol. 1979 Jan;286:255–264. doi: 10.1113/jphysiol.1979.sp012617. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Crawford E. C., Jr, Palomeque J., Barber B. J. A physiological basis for head-body temperature differences in a panting lizard. Comp Biochem Physiol A Comp Physiol. 1977;56(2):161–163. doi: 10.1016/0300-9629(77)90178-5. [DOI] [PubMed] [Google Scholar]
  11. FINDLAY J. D., INGRAM D. L. Brain temperature as a factor in the control of thermal polypnoea in the ox (Bos taurus). J Physiol. 1961 Jan;155:72–85. doi: 10.1113/jphysiol.1961.sp006614. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. FUSCO M. M., HARDY J. D., HAMMEL H. T. Interaction of central and peripheral factors in physiological temperature regulation. Am J Physiol. 1961 Mar;200:572–580. doi: 10.1152/ajplegacy.1961.200.3.572. [DOI] [PubMed] [Google Scholar]
  13. Hammel H. T. Regulation of internal body temperature. Annu Rev Physiol. 1968;30:641–710. doi: 10.1146/annurev.ph.30.030168.003233. [DOI] [PubMed] [Google Scholar]
  14. Hofmeyr H. S., Guidry A. J., Waltz F. A. Effects of temperature and wool length on surface and respiratory evaporative losses of sheep. J Appl Physiol. 1969 May;26(5):517–523. doi: 10.1152/jappl.1969.26.5.517. [DOI] [PubMed] [Google Scholar]
  15. Jessen C., Pongratz H. Air humidity and carotid rete function in thermoregulation of the goat. J Physiol. 1979 Jul;292:469–479. doi: 10.1113/jphysiol.1979.sp012865. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Khamas W. A., Ghoshal N. G. Histomorphologic studies of the nasal cavity of sheep (Ovis aries) and its significance in temperature regulation of the brain. Acta Anat (Basel) 1982;113(4):340–351. doi: 10.1159/000145568. [DOI] [PubMed] [Google Scholar]
  17. Kluger M. J., D'Alecy L. G. Brain temperature during reversible upper respiratory bypass. J Appl Physiol. 1975 Feb;38(2):268–271. doi: 10.1152/jappl.1975.38.2.268. [DOI] [PubMed] [Google Scholar]
  18. Krabill V. A., Ghoshal N. G. Effect of tracheal by-pass on brain temperature and cerebrospinal fluid pressure in sheep. Zentralbl Veterinarmed A. 1983 Aug;30(7):542–551. doi: 10.1111/j.1439-0442.1983.tb01016.x. [DOI] [PubMed] [Google Scholar]
  19. Magilton J. H., Swift C. S. Response of veins draining the nose to alar-fold temperature changes in the dog. J Appl Physiol. 1969 Jul;27(1):18–20. doi: 10.1152/jappl.1969.27.1.18. [DOI] [PubMed] [Google Scholar]
  20. Mehta A. C., Baker R. N. Persistent neurological deficits in heat stroke. Neurology. 1970 Apr;20(4):336–340. doi: 10.1212/wnl.20.4.336. [DOI] [PubMed] [Google Scholar]
  21. Mercer J. B., Jessen C. Central thermosensitivity in conscious goats: hypothalamus and spinal cord versus residual inner body. Pflugers Arch. 1978 May 18;374(2):179–186. doi: 10.1007/BF00581299. [DOI] [PubMed] [Google Scholar]
  22. Mitchell D., Laburn H. P. Pathophysiology of temperature regulation. Physiologist. 1985 Dec;28(6):507–517. [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES