Pflügers Archiv

, Volume 367, Issue 1, pp 25–31 | Cite as

Lingual blood flow and its hypothalamic control in the dog during panting

  • H. Krönert
  • K. Pleschka


  1. 1.

    The effects of increased ambient temperature (Ta) on blood-flow and-temperatures of the tongue were studied in the unanaesthetized dog. At Ta of 20° C and a relative humidity (rh) of 30% the mean lingual blood flow was 11 ml · min−1 (0.15 ml · g−1 · min−1) and the temperature difference between the lingual artery and vien (ΔTLAV) was 1.0° C. Accordingly, a heat loss of 48.6 J · min−1 was calculated even for the dog breathing with the mouth closed. When Ta was elevated to 38° C at constant rh, panting ensued. In parallel fashion lingual blood flow increased to 60.4 ml · min−1 (0.81 ml · g−1 · min−1) in mean and to 74.7 ml · min−1 (0.99 ml · g−1 · min−1) at peak rate of thermal tachypnoea (272 breaths · min−1). This flow increase resulted from a decrease in the local vascular resistance since the driving systemic pressure remained constant. It was accompanied by an increase in TLAV to 1.5° C equivalent to a heat loss of 400.7 J · min−1 in mean and 496.2 J · min−1 at maximum respiratory rate.

  2. 2.

    The preoptic/anterior hypothalamic (PO/AH) region was heated with a water perfused thermode in urethane anaesthetized dogs at constant body temperature in order to study the relationship in time between the increase in lingual blood flow and the onset of thermal panting. Lingual blood flow was found to be 20 ml · min−1 at a respiratory rate of 60 breaths/min. During hypothalamic heating both respiratory rate and lingual blood flow increased markedly. At maximum respiratory rates (244 breaths · min−1) lingual blood flow reached a level of 60 ml · min−1. When perfusion of the thermode was stopped, both respiratory rate and lingual blood flow synchronously returned to control values within 5 min. Similar changes did not occur in dogs in which a ventilatory response failed to be elicited during hypothalamic heating.

  3. 3.

    The results suggest that the tongue contributes to the evaporative heat loss mechanism and they confirm the concept that panting, associated with increased lingual blood flow, is induced by a common autonomic outflow pattern which is mediated by the central mechanism controlling thermal homeostasis.


Key words

Temperature regulation Hypothalamus Panting Lingual blood flow Evaporative respiratory heat loss 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Blatt, Ch. M., Taylor, C. R., Habal, M. B.: Thermal panting in dogs: The lateral nasal gland, a source of water for evaporative cooling. Science177, 804–805 (1972)Google Scholar
  2. Cranston, W. I., Gerbrandy, J., Snell, E. S.: Oral, rectal and oesophageal temperatures and some factors affecting them in man. J. Physiol. (Lond.)126, 347–358 (1954)Google Scholar
  3. Dampney, R. A. L.: Cardiovascular alterations associated with bursts of panting in the exercising dog. J. Physiol. (Lond.)238, 17–36 (1974)Google Scholar
  4. Ederstrom, H. E.: Blood flow changes in the dog during hyperthermia. Amer. J. Physiol.176, 347–351 (1954)Google Scholar
  5. Erici, J., Uvnäs, B.: Efferent and antidromic vasodilator impulses to the tongue in the chorda-lingual nerve of the cat. Acta physiol. scand.25, 10–14 (1952)Google Scholar
  6. Fitzgerald, M. J. T., Alexander, R. W.: The intramuscular ganglia of the cat's tongue. J. Anat. (Lond.)105, 27–46 (1969)Google Scholar
  7. Hales, J. R. S.: Effects of exposure to hot environments on the regional distribution of blood flow and on cardiorespiratory function in sheep. Pflügers Arch.344, 133–148 (1973)Google Scholar
  8. Hales, J. R. S.: Physiological responses to heat. In: Environmental physiology (D. Robertshaw, ed.) Vol. 7. MTP International Review of Science Physiology, Series One. London: Butterworths University Park Press 1974Google Scholar
  9. Hales, J. R. S., Dampney, R. A. L.: The redistribution of cardiac output in the dog during heat stress. J. Thermal Biol.1, 29–34 (1975)Google Scholar
  10. Hales, J. R. S., Fawcett, A. A., Bennett, J. W.: Differential influences of CNS and superficial body temperatures on the partition of cutaneous blood flow between capillaries and arteriovenous anastomoses (AVA's). Pflügers Arch.361, 105–106 (1975)Google Scholar
  11. Hammel, H. T., Hardy, J. D., Fusco, M. M.: Thermoregulatory response of hypothalamic cooling in unanaesthetized dogs. Amer. J. Physiol.198, 481–486 (1960)Google Scholar
  12. Hammel, H. T., Wyndham, C. H., Hardy, J. D.: Heat production and heat loss in the dog at 8–36°C environmental temperature. Amer. J. Physiol.194, 99–108 (1958)Google Scholar
  13. Hellekant, G.: Circulation of the tongue. In: Oral physiology (N. Emmelin and Y. Zotterman, eds.). Oxford-New York-Toronto-Sydney-Braunschweig: Pergamon Press Ltd. 1972Google Scholar
  14. Kindermann, W., Pleschka, K.: Local blood flow and metabolism of the tongue before and during panting in the dog. Pflügers Arch.340, 251–262 (1973)Google Scholar
  15. Kullmann, R., Schönung, W., Simon, E.: Antagonistic changes of blood flow and sympathetic activity in different vascular beds following central thermal stimulation. I. Blood flow in skin, muscle and intestine during spinal cord heating and cooling in anaesthetized dogs. Pflügers Arch.319, 146–161 (1970)Google Scholar
  16. Lim, R. K. S., Liu, C., Moffitt, R. L.: A stereotaxic atlas of the dog brain. Springfield, Ill.: Ch. C. Thomas 1960Google Scholar
  17. Meyer, M. W.: Distribution of cardiac output to oral tissues in dogs. J. Dent. Res.49, 787–794 (1970)Google Scholar
  18. Schenk, E. A., Badawi, A. E.: Dual innervation of arteries and arterioles. Z. Zellforsch.91, 170–177 (1968)Google Scholar
  19. Schmidt-Nielsen, K., Bretz, W. L., Taylor, C. R.: Panting in dogs: Unidirectional air flow over evaporative surfaces. Science169, 1102–1104 (1970)Google Scholar
  20. Strydom, N. B., Wyndham, C. H., Williams, C. G., Morrison, J. F., Bredell, G. A., Joffe, A.: Oral rectal temperature differences during work and heat stress. J. appl. Physiol.20, 283–287 (1965)Google Scholar
  21. Verzár, F., Keith, J., Parchet, V.: Temperatur und Feuchtigkeit in den Atemwegen. Pflügers Arch. ges. Physiol.257, 400–416 (1953)Google Scholar
  22. Webb, P.: Air temperatures in respiratory tracts of resting subjects in cold. J. Appl. Physiol.4, 378–382 (1951)Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • H. Krönert
    • 1
  • K. Pleschka
    • 1
  1. 1.W. G. Kerckhoff-InstitutMax-Planck-Institut für Physiologische und Klinische ForschungBad NauheimFederal Republic of Germany

Personalised recommendations