Differential effects of stress on [¹¹C]raclopride and [¹¹C]MNPA binding to striatal D₂/D₃ dopamine receptors: a PET study in conscious monkeys.
It has been reported that stress and facilitation of dopamine neuronal system are closely related. In the present study, the effects of stress on the binding of antagonist-based [¹¹C]raclopride and agonist-based (R)-2-CH3O-N-n- propylnorapomorphine ([¹¹C]MNPA) to D₂/D₃ receptors were evaluated in the striatum of conscious monkey brain. The stress state assessed from plasma cortisol level was negatively correlated with [¹¹C]raclopride binding as expected. It was noteworthy that [¹¹C]MNPA binding exhibited a positive correlation with stress state; thus, the animals with higher cortisol levels showed higher binding to D₂/D₃ receptors.
Tsukada
Hideo
H
Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Hamamatsu, Shizuoka, Japan. tsukada@crl.hpk.co.jp
Ohba
Hiroyuki
H
Nishiyama
Shingo
S
Kakiuchi
Takeharu
T
D000818:Animals; D001058:Apomorphine / Q000378:metabolism* / Q000494:pharmacology; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism* / Q000494:pharmacology; D006854:Hydrocortisone / Q000097:blood; D008253:Macaca mulatta; D008297:Male; D049268:Positron-Emission Tomography; D020891:Raclopride / Q000378:metabolism* / Q000494:pharmacology; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*; D013312:Stress, Physiological / Q000502:physiology*
D002250:Carbon Radioisotopes; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D020891:Raclopride; D001058:Apomorphine; D006854:Hydrocortisone