Effects of imipramine on extracellular serotonin and noradrenaline concentrations in ACTH-treated rats.
We investigated the effect of imipramine on extracellular serotonin (5-HT) and noradrenaline concentrations in the medial prefrontal cortex of rats treated with adrenocorticotropic hormone (ACTH) for 14 days using in vivo microdialysis. Chronic ACTH treatment did not affect basal extracellular 5-HT and noradrenaline concentrations compared with chronic saline treatment. Acute imipramine treatment plus chronic ACTH treatment significantly increased extracellular 5-HT concentrations, compared with imipramine treatment alone. 8-hydroxy-2-di-n-propylamino tetralin (8-OH-DPAT), a 5-HT1A receptors full agonist, caused a significant decrease in extracellular 5-HT concentrations. However, its inhibitory effect was attenuated by the treatment with ACTH for 14 days. These findings suggest that chronic treatment with ACTH enhances the increasing effect release of 5-HT by imipramine through the desensitization of somatodendritic 5-HT1A autoreceptors.
Kitamura
Yoshihisa
Y
Department of Pharmaceutical Care and Health Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan. ykita@pheasant.pharm.okayama-u.ac.jp
Akiyama
Kozue
K
Hashimoto
Shinji
S
Kitagawa
Kouhei
K
Kawasaki
Hiromu
H
Shibata
Kazuhiko
K
Shinomiya
Kazuaki
K
Suemaru
Katsuya
K
Araki
Hiroaki
H
Sendo
Toshiaki
T
Gomita
Yutaka
Y
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D003345:Corticosterone / Q000097:blood; D007099:Imipramine / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D058825:Serotonin 5-HT1 Receptor Agonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D018759:Adrenergic Uptake Inhibitors; D000929:Antidepressive Agents, Tricyclic; D058825:Serotonin 5-HT1 Receptor Agonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000324:Adrenocorticotropic Hormone; D007099:Imipramine; D003345:Corticosterone; D009638:Norepinephrine