Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Seasonal thermogenic capacity in a hibernator,Spermophilus richardsonii

Summary

The maximum thermogenic capacity (HPmax) and the maximum capacity for non-shivering thermogenesis (NSTmax) were assessed in a hibernator, the Richardson's ground squirrel at different times of year. The HPmax was elicited by exposing animals to He−O2 (21% oxygen, balance helium) at −10 to −25°C. The NSTmax was estimated by i.v. infusion of isoproterenol in anesthetized animals at thermoneutrality. Non-hibernating phase adults were collected and tested in April and June, and youngs in June and August for effects of seasonal acclimatization; animals were also tested after acclimation to cold (5°C) or warm (20°C). Hibernating phase animals were tested both shortly after the onset of hibernation season and after several months into the hibernation season. Although HPmax differed significantly between the lowest [101 cal (wt0.73·h)−1 in the June-Young group] and the highest [142 cal (wt0.73·h)−1 in the June-Adult group], it was not significantly different between other groups regardless of hibernation status or temperature acclimation (Fig. 4). The NSTmax, however, increased from 40–50 cal (wt0.73·h)−1 in the Warm-Acclimated, August-Young, June-Adult, and April-Adult to 66.5 and 79.2 cal (wt0.73·h)−1 in the two hibernating groups (Fig. 3). No significant difference in NSTmax was observed between Cold- and Warm-Acclimated groups. Since HPmax was maintained essentially constant at different times of year or after temperature acclimation, the increase of NSTmax during the hibernating phase can best be viewed as an adjustment for facilitation of periodic rewarmings from depressed body temperature during hibernation rather than to counter cold.

This is a preview of subscription content, log in to check access.

Abbreviations

HP :

heat production

HPmax :

maximum heat production

NST :

non-shivering thermogenesis

NSTmax :

maximum non-shivering thermogenesis

ST :

shivering thermogenesis

T a :

ambient temperature

T b :

body temperature

References

  1. Cottle, W.H.: Calorigenic response of cold-adapted rabbits to adrenalin and noradrenalin. Can. J. Biochem. Physiol.41, 1334–1337 (1963)

  2. Cottle, W.A., Carlson, L.D.: Regulation of heat production in cold-acclimated rats. Proc. Soc. Exp. Biol. Med.92, 845–848 (1956)

  3. Feist, D.D., Rosenmann, M.: Seasonal sympathoadrenal and metabolic responses to cold in the Alaskan snowshoe hare (Lepus americanus macfarlani). Comp. Biochem. Physiol.51A, 449–455 (1975)

  4. Feist, D.D., Rosenmann, M.: Norepinephrine thermogenesis in seasonally acclimatized and cold acclimated red-backed voles in Alaska. Can. J. Physiol. Pharmacol.54, 146–153 (1976)

  5. Glass, J.D., Wang, L.C.H.: Effects of central injection of biogenic amines during arousal from hibernation. Am. J. Physiol.236, R162–167 (1979)

  6. Hart, J.S.: Rodents. In: Comparative physiology of thermoregulation, Vol. 3. Whitow, G.C. (ed.), pp. 2–150. New York: Academic Press 1971

  7. Hart, J.S., Heroux, O.: Seasonal acclimatization in wild rats (Rattus norvegicus). Can. J. Zool.41, 711–716 (1963)

  8. Hayward, J.S.: Non-shivering thermogenesis in hibernating mammals. In: Non-shivering thermogenesis. Jansky, L. (ed.), pp. 119–137. Prague: Academia 1971

  9. Hayward, J.S., Lyman, C.P.: Non-shivering heat production during arousal from hibernation and evidence for the contribution of brown fat. In: Mammalian hibernation III. Fisher, K.C., Dawe, A.R., Lyman, C.P., Schönbaum, E., South, F.E., Jr. (eds.), pp. 346–355. Toronto: Oliver and Boyd 1967

  10. Horwitz, B.A.: Neurohumoral regulation of non-shivering thermogenesis in mammals. In: Strategies in cold: Natural torpidity and thermogenesis. Wang, L.C.H., Hudson, J.W. (eds.), pp. 619–653. New York: Academic Press 1978

  11. Jansky, L.: Non-shivering thermogenesis and its thermoregulatory significance. Biol. Rev.48, 85–143 (1973)

  12. Kleiber, M.: The fire of life, p. 125. New York: John Wiley 1961

  13. Lynch, G.R.: Seasonal changes in thermogenesis, organ weights and body composition in the white-footed mouse,Peromyscus leucopus. Oecologia (Berlin)13, 363–376 (1973)

  14. MacClintock, D.: Squirrels in North America, pp. 37–48. New York: Nostrand Reinhold 1970

  15. Michener, D.R.: Annual cycle of activity and weight changes in Richardson's ground squirrel,Spermophilus richardsonii. Can. Field Nat.88, 408–413 (1974)

  16. Musacchia, X.J.: Heat and cold acclimation in helium-cold hypothermia in the hamster. Am. J. Physiol.222, 495–498 (1972)

  17. Petrović, V.M., Marković-Giaja, L., Stamatović, G.: Influence de la saison sur l'effet calorigenique de la noradrenaline chez le spermophile. J. Physiol.65, 475A (1972)

  18. Pohl, H.: Temperature regulation and cold acclimation in the golden hamster. J. Appl. Physiol.20, 405–410 (1965)

  19. Pohl, H., Hart, J.S.: Temperature regulation and cold acclimation in a hibernator,Citellus tridecemlineatus. J. Appl. Physiol.20, 398–404 (1965)

  20. Rosenmann, M., Morrison, P.: Maximum oxygen consumption and heat loss facilitation in small homeotherms by He−O2. Am. J. Physiol.226, 490–495 (1974)

  21. Rosenmann, M., Morrison, P., Feist, D.: Seasonal changes in the metabolic capacity of red-backed voles. Physiol. Zool.48, 303–310 (1975)

  22. Wang, L.C.H.: Factors limiting maximum cold-induced heat production. Life Sci.23, 2089–2098 (1978)

  23. Wang, L.C.H.: Time patterns and metabolic rates of natural torpor in Richardson's ground squirrel. Can. J. Zool.57, 149–155 (1979)

  24. Wang, L.C.H., Peter, R.E.: Metabolic and respiratory responses during Helox-induced hypothermia in the white rat. Am. J. Physiol.229, 890–895 (1975)

Download references

Author information

Correspondence to Lawrence C. H. Wang.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Abbotts, B., Wang, L.C.H. Seasonal thermogenic capacity in a hibernator,Spermophilus richardsonii . J Comp Physiol B 140, 235–240 (1980). https://doi.org/10.1007/BF00690408

Download citation

Keywords

  • Helium
  • Human Physiology
  • Body Temperature
  • Isoproterenol
  • Maximum Capacity