Reduction of dopamine D2/3receptor binding in the striatum after a single administration of esketamine, but not R-ketamine: a PET study in conscious monkeys.
R-ketamine appears to be a potent, long-lasting and safer antidepressant, relative to esketamine (S-ketamine), since it might be free of psychotomimetic side effects. Using [11C]raclopride and positron emission tomography (PET), we investigated whether esketamine and R-ketamine can affect dopamine D2/3receptor binding in the conscious monkey brain. A single infusion of esketamine (0.5 mg/kg), but not R-ketamine (0.5 mg/kg), caused a reduction of binding availability of dopamine D2/3receptor in the monkey striatum. This study suggests that unlike to R-ketamine, esketamine can cause dopamine release in the striatum, and that its release might be associated with psychotomimetic effects of esketamine.
Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, 1-8-1 Inohana, Chiba, Chiba, 260-8670, Japan. hashimoto@faculty.chiba-u.jp.
Kenji
K
Hashimoto
Central Research Laboratory, Hamamatsu Photonics KK, Hamamatsu, Shizuoka, 434-0041, Japan.
Takeharu
T
Kakiuchi
Central Research Laboratory, Hamamatsu Photonics KK, Hamamatsu, Shizuoka, 434-0041, Japan.
Hiroyuki
H
Ohba
Central Research Laboratory, Hamamatsu Photonics KK, Hamamatsu, Shizuoka, 434-0041, Japan.
Shingo
S
Nishiyama
Central Research Laboratory, Hamamatsu Photonics KK, Hamamatsu, Shizuoka, 434-0041, Japan.
Hideo
H
Tsukada
D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D008253:Macaca mulatta; D008297:Male; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000187:drug effects*; D049268:Positron-Emission Tomography / Q000379:methods*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*
D000928:Antidepressive Agents; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D007649:Ketamine
Dopamine D2/3 receptor; Esketamine; Monkey; R-ketamine; Release