Evidence for functional interactions between 5-HT1A and 5-HT2A receptors in rat thermoregulatory mechanisms.
The present study was designed to examine 1) functional interactions between 5-HT1A and 5-HT2A/C receptors in thermoregulation in rats and 2) the specific involvement of 5-HT2A and 5-HT2C receptors in such interactions. The 5-HT2A/C receptor agonist DOI (0.025 1.6 mg kg-1, subcutaneously) produced a dose-dependent hyperthermia in rats, which was enhanced by addition of either of two 5-HT1A receptor antagonists, (-)-pindolol (0.5-1.0 mg kg-1, subcutaneously) or WAY-100,635 (0.1-0.4 mg kg-1, subcutaneously). Furthermore, the DOI-induced hyperthermia was counteracted by pretreatment with the 5-HT1A receptor agonist 8-OH-DPAT (0.05 mg kg-1, subcutaneously). The hyperthermia produced by DOI, alone or in combination with WAY-100,635, was fully antagonized by pretreatment with the 5-HT2A/C receptor antagonist ritanserin (1.0 mg kg-1, subcutaneously), as well as with the selective 5-HT2A receptor antagonist amperozide (2.0 mg kg-1, subcutaneously). The present results provide evidence for functional interactions between 5-HT1A and 5-HT2A receptors in temperature regulation in rats, and also suggest an important role for postsynaptic 5-HT2A receptors in the mediation of DOI-induced hyperthermia.
Salmi
P
P
Department of Psychology, Stockholm University, Sweden.
Ahlenius
S
S
D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D001833:Body Temperature Regulation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D000662:Amphetamines; D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine