Blood flow through the ophthalmic veins during exercise in humans

  • Masami Hirashita
  • Osamu Shido
  • Minoru Tanabe
Article

Summary

The blood from the face flows into the intracranium through the ophthalmic veins when human subjects become hyperthermic. To investigate a possible mechanism underlying this change in direction of flow, five young men were subjected to either passive body warming or exercise on a cycle ergometer, in a climatic chamber whose air temperature and relative humidity were 28°C and 40%. Tympanic (Tty) and oesophageal temperatures, forehead sweat rate (msw), skin blood flow. (Qsk) and blood flow through the ophthalmic vein (Qov) were measured, and the mean skin (Tsk) and mean body (Tb) temperatures were computed. Passive body warming was induced by a box-shaped body warming unit enclosing all but the subject's head. Exercise was performed either at an intensity of 60% maximal oxygen consumption or with the intensity increasing in increments. During both tests, msw and Qsk started to increase shortly after the imposition of the heat load. The Qov began to change with the venous blood flowing from the face into the intracranium and a complete reversal in the direction of Qov (from the face to the intracranium). came significantly later than the increases in Qsw and Qsk. The Tty at the time of flow reversal was the same in both tests. The Tsk (and hence Tb) at flow reversal was, however, significantly higher during passive body warming than during exercise. The mechanism for switching the direction of Qov appeared to have been triggered by a high temperature in the brain, and not by thermal input from the periphery of the body. In a febrile subject who volunteered for this study, the direction of Qov was consistently inwards even when sitting quietly. From these results, we suggest that there are elements within the brain that control the mechanisms for switching the direction of venous flow through the emissary veins to keep the brain cool during hyperthermia.

Key words

Passive body warming Cycle exercise Emissary veins Flow reversal Tympanic temperature Oesophageal temperature 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Baker MA (1982) Brain cooling in endotherms in heat and exercise. Ann Rev Physiol 44:85–96Google Scholar
  2. Bowler K, Tirri R (1974) The temperature characteristics of synaptic membrane ATPases from immature and adult rat brain. J Neurochem 23:611–613Google Scholar
  3. Brengelmann GL (1987) Dilemma of body temperature measurement. In: Shiraki K, Yousef MK (eds) Man in stressful environments: thermal and work physiology. Thomas, Springfield, pp 5–22Google Scholar
  4. Brinnel H, Cabanac M (1989) Tympanic temperature is a core temperature in humans. J Therm Biol 14:47–53Google Scholar
  5. Cabanac M (1986) Keeping a cool head. News Phys Sci 1:41–44Google Scholar
  6. Cabanac M, Caputa M (1979a) Natural selective cooling of the human brain: evidence of its occurrence and magnitude. J Physiol (Lond) 286:255–264Google Scholar
  7. Cabanac M, Caputa M (1979b) Open loop increase in trunk temperature produced by face cooling in working humans. J Physiol (Lond) 289:163–174Google Scholar
  8. Cabanac M, Brinnel H (1985) Blood flow in the emissary veins of the human head during hyperthermia. Eur J Appl Physiol 54:172–176Google Scholar
  9. Cannon JG, Kluger MJ (1983) Endogenous pyrogen activity in human plasma after exercise. Science 220:617–619Google Scholar
  10. Caputa M (1980) Selective brain cooling: an important component of thermal physiology. In: Szelényi Z, Székely M (eds) Contributions to thermal physiology. Pergamon Press, Oxford, pp 183–192Google Scholar
  11. Caputa M, Perrin G, Cabanac M (1978) Écoulement sanguin réversible dans la veine ophthalmique: mécanisme de refroidissement sélectif du cerveau humain. C R Acad Sci (Paris) 287D:1011–1014Google Scholar
  12. Caputa M, Kadziela W, Narebski J (1983) Cerebral temperature regulation in resting and running guinea-pigs (Cavia porcellus). J Therm Biol 8:265–272Google Scholar
  13. Elkhawad AO, Khogali M, Thulesius O (1986) Does the facial vein of the sheep have a role in cranial thermoregulation? Abstracts of the Satellite Symposium of Thermal Physiology; 30th International Congress of Physiological Sciences, Alberta, Canada. University of Calgary, p 22Google Scholar
  14. Elkhawad AO, Al-Zaid NS, Bou-Resli MN (1990) Facial vessels of desert camel (Camelus dromedarius): role in brain cooling. Am J Physiol 258:R602-R607Google Scholar
  15. Hirata K, Nagasaka T, Hirai A, Hirashita M, Takahata T (1984a) Cutaneous vascular tone during heat load modified by exercise intensity. J Therm Biol 9:117–120Google Scholar
  16. Hirata K, Nagasaka T, Hirai A, Hirashita M, Takahata T (1984b) Suppression of finger vasodilator response during exercise in proportion to its intensity. In: Hales JRS (ed) Thermal physiology. Raven Press, New York, pp 381–384Google Scholar
  17. Hirata K, Nagasaka T, Hirai A, Hirahita M, Takahata T, Nunomura T (1986) Effects of human menstrual cycle on thermoregulatory vasodilatation during exercise. Eur J Appl Physiol 54:559–565Google Scholar
  18. Hirata K, Nagasaka T, Nunomura T, Hirai A, Hirahita M (1987) Effects of facial fanning on local exercise performance and thermoregulatory responses during hyperthermia. Eur J Appl Physiol 56:43–48Google Scholar
  19. Iwabuchi T, Sobata E, Ebina K (1986) Dural sinus pressure: various aspects in human brain surgery in children and adults. Am J Physiol 250:H389-H396Google Scholar
  20. Johnsen HK, Folkow LP (1988) Vascular control of brain cooling in reindeer. Am J Physiol 254:R730-R739Google Scholar
  21. Johnson HK, Blix AS, Mercer JB, Bolz K-D (1987) Selective cooling of the brain in reindeer. Am J Physiol 253:R848-R853Google Scholar
  22. Maron MB, Wagner JA, Horvath SM (1977) Thermoregulatory responses during competitive marathon running. J Appl Physiol 42:909–914Google Scholar
  23. Mellander S, andersson P-O, Afzelius L-E, Hellstrand P (1982) Neural betaadrenergic dilatation of the facial vein in man. Acta Physiol Scand 114:393–399Google Scholar
  24. Nadel ER (1979) Control of sweating rate while exercising in the heat. Med Sci Sports 11:31–35Google Scholar
  25. Nadel ER (1987) Coments on “keeping a cool head”. News Phys Sci 2:33–34Google Scholar
  26. Nagasaka T, Hirashita M, Tanabe M, Sakurada S, Brinnel H (1990) Role of the veins of the face brain cooling during body warming in human subjects. Jpn J Biometeorol 27:113–120Google Scholar
  27. Nielsen M (1938) Die Regulation der Körpertemperatur bei Muskelarbeit. Skand Arch Physiol 79:193–230Google Scholar
  28. Shibolet S, Lancaster MC, Dannon Y (1976) Heat stroke: a review. Aviat Space Environ Med 47:280–301Google Scholar
  29. Shido O, Nagasaka T (1986) Thermal balance during intraperitoneal electric heating at various ambient temperature in rats. Jpn J Aerosp Environ Med 23:27–32Google Scholar
  30. Shiraki K, Sagawa S, Tajima F, Yokota A, Hashimoto M, Brengelmann GL (1988) Independence of brain and tympanic temperatures in an unanesthetized human. J Appl Physiol 65:482–486Google Scholar
  31. Stitt JT (1979) Fever versus hyperthermia. Fed Proc 38:39–43Google Scholar
  32. Takagi K, Ogawa T, Kobayashi M, Satoh T (1966) Observations on sweating rate by continuous recordings. In: Yoshimura H, Weiner JS (eds) Human adaptability and its methodology. Japan Society for the Promotion of Sciences, Tokyo, pp 130–134Google Scholar
  33. Tanaka H, Kanosue K, Yanase M, Nakayama T (1990) Effects of pyrogen administration on temperature regulation in exercising rats. Am J Physiol 258:R842-R847Google Scholar
  34. Wenger CB (1987) More comments on “keeping a cool head” News Phys Sci 2:150Google Scholar
  35. Winquist RJ, Bevan JA (1980) Temperature sensitivity of tone in the rabbit facial vein: myogenic mechanism for cranial thermoregulation. Science 207:1001–1002Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Masami Hirashita
    • 1
  • Osamu Shido
    • 2
  • Minoru Tanabe
    • 2
  1. 1.Kanazawa College of EconomicsGosho-machi, KanazawaJapan
  2. 2.Department of Physiology, School of MedicineKanazawa UniversityTakara-machi, KanazawaJapan

Personalised recommendations