Abstract
Torpor-like circadian variations of core temperature are well documented for suckling-age Zucker rat pups. To determine (1) whether this juvenile circadian rhythm is as strongly expressed in other rat strains, and (2) whether a similar rhythm is expressed in rabbit pups, we recorded core temperature and metabolic rate of artificially reared pups. Wistar, Brown Norway, and Long Evans pups were studied for 30 h under moderate cold loads (ambient temperature=28°C) when 9–11 days old, i.e. at the age and ambient temperature for which the rhythm has been most thoroughly characterized in Zucker rats. Chinchilla bastard rabbit pups were studied under similar conditions when they were 3–8 days old, the youngest age at which the rhythm can be easily detected in rats. Rat pups of each strain showed clear circadian rhythms with sharp decreases of core temperature and metabolic rate in subjective morning. Core temperature amplitudes were in the order Wistar < Brown Norway < Zucker < Long Evans strain. In contrast, the rabbit pups maintained stable high levels of core temperature and metabolic rate throughout the day. A torpor-like decrease of core temperature in the morning is thus not a pecularity of the Zucker rat strain but also occurs in other pigmented rat strains, whereas rabbit pups at a similar developmental stage do not show a circadian core temperature rhythm.
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Abbreviations
- bm:
-
body mass
- MR:
-
metabolic rate
- RH:
-
relative air humidity
- T a :
-
ambient temperature
- T c :
-
core temperture
References
Ader R, Grota LJ (1970) Rhythmicity in the maternal behavior of Rattus norvegicus. Anim Behav 18:144–150
Angermann R (1972) Die Hasentiere. In: Grzimeks Tierleben, Enzyklopädie des Tierreiches. Kindler Verlag AG, Zürich, pp 419–465
Enright DT (1965) The search for rhythmicity in biological timeseries. J Theor Biol 8:426–468
Geiser F (1988) Reduction of metabolism during hibernation and daily torpor in mammals and birds: temperature effect or physiological inhibition? J Comp Physiol B 158:25–37
Harkness JE, Wagner JE (1983) The biology and medicine of rabbits and rodents. Lea and Febiger, Philadelphia
Hudson R, Distel H (1982) The pattern of behaviour of rabbit pups in the nest. Behaviour 79:255–271
Hudson R, Distel H (1989) Temporal pattern of suckling in rabbit pups: a model of circadian synchrony between mother and young. In: Reppert SM (ed) Development of circadian rhythmicity and photoperiodism in mammals, Perinatology Press, Boston, pp 83–101
Hull D (1965) Oxygen consumption and body temperature of newborn rabbits and kittens exposed to cold. J Physiol (London) 177:192–202
Kaul R, Heldmaier G, Schmidt I (1990) Defective thermoregulatory thermogenesis does not cause onset of obesity in Zucker rats. Am J Physiol 259:E11-E18
Körtner G, Schildhauer K, Petrova O, Schmidt I (1993) Rapid changes in metabolic cold defense and GDP-binding to brown adipose tissue mitochondria of rat pups. Am J Physiol 264: R1017-R1023
Markewicz B, Kuhmichel G, Schmidt I (1993) Onset of excess fat deposition in Zucker rats with and without decreased thermogenesis. Am J Physiol 265:E478-E486
Messer M, Thoman EB, Terrasa AG, Dallman PR (1969) Artificial feeding of infant rats by continuous gastric infusion. J Nutr 98: 404–410
Mumm B, Kaul R, Heldmaier G, Schmidt I (1989) Endogenous 24-hour cycle of core temperature and oxygen consumption in week-old Zucker rat pups. J Comp Physiol B 159:569–575
Mumm B, Kaul R, Heldmaier G, Schmidt I (1990) Endogenous circadian core temperature rhythm in artificially reared week-old Wistar rats. In: Morgan E (ed) Chronobiology and chronomedicine, Peter Lang, Frankfurt, pp 92–101
Nedergaard J, Connolly E, Cannon B (1986) Brown adipose tissue in the mammalian neonate. In: Trayhurn P, Nicholls DG (eds) Brown Adipose Tissue. Arnold, London, pp 152–213
Nuesslein B (1993) Der juvenile circadiane Kerntemperatur-Rhythmus von Ratten: Physiologische Grundlagen und synchronisierende Faktoren. Dr.-Thesis, Univerität Marburg
Nuesslein B, Schmidt I (1990) Development of circadian cycle of core temperature in juvenile rats. Am J Physiol 259:R270-R276
Nuesslein B, Kaul R, Schmidt I (1989) Absence of 24-hour core temperature cycle in rat pups artificially reared under thermoneutral conditions. In: Mercer JB (ed) Thermal physiology, Elsevier, Amsterdam, pp 315–320 [Excerpta of Medicine Intenational Congress Series]
Nuesslein B, Petrova O, Schildhauer K, Schmidt I (1994) Morning depression of cold defense in juvenile rats. In: Pleschka K, Gerstberger R (eds) Integrative and cellular aspects of autonomic functions, John Libbey, London, pp 295–304
Nuesslein-Hildesheim B, Schmidt I (1994) Is the core temperature rhythm of juvenile rats due to a periodic blockade of thermoregulatory thermogenesis? Pfügers Arch. 427:450–454
Planche E, Joliff M (1987) Evolution desépenses énergétiques chez le rat Zucker au cours de la première semaine de la vie. Effet de l'heure des mesures. Reprod Nutr Dévelop. 27:673–679
Redlin U, Nuesslein B, Schmidt I (1992) Circadian changes of brown adipose tissue thermogenesis in juvenile rats. Am J Physiol 262: R504-R508
Romijn HJ, Hofman MA, Gramsbergen A (1991) At what age is the developing cerebral cortex of the rat comparable to that of the full-term newborn human baby? Early Hum Dev 26:61–67
Schley P (1980) Die mutterlose Aufzucht von Kaninchen Das Blaue Kaninchen-Jahrbuch Deutscher Kleintierzüchter, Reuttingen
Schmidt I, Barone A, Carlisle HJ (1986) Diurnal cycle of core temperature in huddling, week-old rat pups. Physiol Behav 7:105–109
Schmidt I, Kaul R, Heldmaier G (1987) Thermoregulation and diurnal rhythms in 1-week-old rat pups. Can J Physiol Pharmacol 65:1355–1364
Sokolove PG, Bushell WN (1987) The chi-square periodogram: its utility for analysis of circadian rhythms. J Theor Biol 72:131–160
Spiers DE (1988) Nocturnal shifts in thermal and metabolic responses of the immature rat. J Appl Physiol 64:2119–2124
Spiers DE, Adair ER (1986) Ontogeny of homeothermy in the immature rat: Metabolic and thermal responses. J Appl Physiol 60:1190–1197
Withers PC (1977) Measurement of \(\dot V_{O_2 } \), \(\dot V_{CO_2 } \) and evaporative water loss with a flow-through mask. J Appl Physiol 42:120–123
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Communicated by H. Langer
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Nuesslein-Hildesheim, B., Imai-Matsumura, K., Döring, H. et al. Pronounced juvenile circadian core temperature rhythms exist in several strains of rats but not in rabbits. J Comp Physiol B 165, 13–17 (1995). https://doi.org/10.1007/BF00264681
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DOI: https://doi.org/10.1007/BF00264681