Modulation of 8-OH-DPAT-induced hypothermia by imipramine in rats.

Abstract

The effects of imipramine on 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), the 5-hydroxytryptamine (5-HT)(1A)-receptor full agonist, -induced hypothermia was examined in rats. Single administration of imipramine (30 mg/kg, i.p.) attenuated 8-OH-DPAT-induced hypothermia. This effect of imipramine was blocked by the 5-HT(2A)-receptor antagonist ketanserin. 8-OH-DPAT-induced hypothermia was not altered 24 h after repeated administration of imipramine (1 - 10 mg/kg per day) for 14 days. However, 8-OH-DPAT-induced hypothermia was significantly enhanced in repeated imipramine (10 mg/kg per day)-treated rats that received 8-OH-DPAT plus imipramine 24 h after the final imipramine administration for 14 days. The 5-HT(2A)-receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane ((+/-)-DOI) attenuated the 8-OH-DPAT-induced hypothermia in drug naive rats. The inhibitory effect of (+/-)-DOI (0.3 mg/kg, s.c.) on 8-OH-DPAT-induced hypothermia was attenuated by repeated administration of imipramine (10 mg/kg per day) for 14 days. These findings suggest that enhancement of the 5-HT(1A) receptors by repeated administration of imipramine may be due to reduction of the inhibitory effects from the 5-HT(2A) receptors to the 5-HT(1A) receptors.

• Authors: Yoshihisa Kitamura, Hiroaki Araki, Kazuhiko Shibata, Yutaka Gomita, Yoshiro Tanizaki
• Journal: Journal of pharmacological sciences (J Pharmacol Sci) Vol. 93 Issue 3 Pg. 259-64 (Nov 2003) ISSN: 1347-8613 [Print] Japan
• PMID: 14646242 (Publication Type: Comparative Study, Journal Article)

Chemical References

• 8-Hydroxy-2-(di-n-propylamino)tetralin
• Imipramine

Topics

• 8-Hydroxy-2-(di-n-propylamino)tetralin (pharmacology)
• Animals
• Dose-Response Relationship, Drug
• Drug Synergism
• Hypothermia (chemically induced, metabolism)
• Hypothermia, Induced (methods)
• Imipramine (pharmacology)
• Male
• Rats
• Rats, Wistar