Effects of corticosterone on 5-HT1A and 5-HT2 receptor binding and on the receptor-mediated behavioral responses of rats.
The effects of corticosterone after binding to 5-HT1A and 5-HT2 receptors were studied in rats. Binding of [3H]8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) to 5-HT1A receptors in the hippocampus decreased 24 h after both acute and chronic (14 day) administration of CORT (50 mg/kg, s.c.). Chronic, but not acute, CORT treatment increased [3H]ketanserin binding to 5-HT2 receptors in the frontal cortex. Receptor-mediated behavioral responses were also examined following acute and chronic CORT treatment. Flat body posture and hypothermia induced by 8-OH-DPAT, a 5-HT1A receptor agonist, were attenuated following chronic, but not acute, CORT administration. (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a 5-HT2 receptor agonist, induced wet-dog shakes, but not hyperthermia and this response was increased 24 h after the chronic administration of CORT. These findings indicate that both 5-HT1A and 5-HT2 receptor functions were changed following chronic exposure to high levels of CORT. Such changes in these receptor systems may play an important role in the etiology of affective disorders.
Takao
K
K
Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine, Japan.
Nagatani
T
T
Kitamura
Y
Y
Yamawaki
S
S
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism; D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D003345:Corticosterone / Q000097:blood / Q000494:pharmacology*; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007650:Ketanserin / Q000378:metabolism; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000378:metabolism*; D014202:Tremor
D000662:Amphetamines; D000893:Anti-Inflammatory Agents; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007650:Ketanserin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine; D003345:Corticosterone