Abstract
1 A new apparatus in which mice are allowed to shuttle between the warm and cool parts of a continuous oval tunnel has been designed for the measurement of drug effects on behavioural thermoregulation.
2 The length of time that untreated mice spent in the warmer part of the apparatus (tunnel wall temperature 38°C) was found to be inversely related to the temperature of the cooler part (wall temperature 18°, 24° or 30°C).
3 Mice treated with 2,4-dinitrophenol at a dose known to be hyperthermic at an ambient temperature of 32°C (20 mg/kg s.c.) spent an increased length of time in the cooler part of the apparatus (wall temperature 18°C) and did not exhibit any change in rectal temperature.
4 Mice treated with pentolinium tartrate at a dose known to be hypothermic at room temperature (5.0 mg/kg i.v.) spent a decreased length of time in the cooler part of the apparatus (wall temperature 24°C) and did not exhibit any change in rectal temperature.
5 It is concluded from the above results that the apparatus can be used to measure drug effects on behavioural thermoregulation.
6 In experiments of 30 min duration, mice treated with Δ9-tetrahydrocannabinol (Δ9-THC) at doses known to be hypothermic and to lower oxygen consumption at room temperature (20 mg/kg i.p. or 2.0 mg/kg i.v.) spent a longer time in the warmer part of the apparatus between 15 and 30 min after injection. Rectal temperatures measured 30 min after injection were only slightly less than those of control mice. In these experiments the wall temperature of the cool tunnel was 24°C.
7 In experiments of 15 min duration, mice treated with Δ9-THC (20 mg/kg) and then placed in the apparatus spent more time in the cooler part of the apparatus (wall temperature 24°C) and exhibited a large fall in rectal temperature.
8 It is concluded that immediately after injection of Δ9-THC the mice do not attempt to oppose drug-induced falls in deep body temperature by moving into a warm environment and that only later do the animals demonstrate a preference for a warm environment.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cox B., Green M. D., Lomax P. Behavioral thermoregulation in the study of drugs affecting body temperature. Pharmacol Biochem Behav. 1975 Nov-Dec;3(6):1051–1054. doi: 10.1016/0091-3057(75)90015-5. [DOI] [PubMed] [Google Scholar]
- Garriott J. C., King L. J., Forney R. B., Hughes F. W. Effects of some tetrahydrocannabinols on hexobarbital sleeping time and amphetamine induced hyperactivity in mice. Life Sci. 1967 Oct 1;6(19):2119–2128. doi: 10.1016/0024-3205(67)90232-9. [DOI] [PubMed] [Google Scholar]
- MASON D. F., WIEN R. The actions of heterocyclic bisquaternary compounds, especially of a pyrrolidinium series. Br J Pharmacol Chemother. 1955 Mar;10(1):124–132. doi: 10.1111/j.1476-5381.1955.tb00070.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pertwee R. G., Tavendale R. Effects of delta9-tetrahydrocannabinol on the rates of oxygen consumption of mice. Br J Pharmacol. 1977 Aug;60(4):559–568. doi: 10.1111/j.1476-5381.1977.tb07535.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Polk D. L., Lipton J. M. Effects of sodium salicylate, aminopyrine and chlorpromazine on behavioral temperature regulation. Pharmacol Biochem Behav. 1975 Mar-Apr;3(2):167–172. doi: 10.1016/0091-3057(75)90143-4. [DOI] [PubMed] [Google Scholar]
- SHEMANO I., NICKERSON M. Mechanisms of thermal responses to 2,4-dinitrophenol. J Pharmacol Exp Ther. 1963 Jan;139:88–93. [PubMed] [Google Scholar]
- Yehuda S., Wurtman R. J. Paradoxical effects of d-amphetamine on behavioral thermoregulation: possible mediation by brain dopamine. J Pharmacol Exp Ther. 1974 Jul;190(1):118–122. [PubMed] [Google Scholar]