The D3-receptor agonist (+/-)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) attenuates morphine-induced hyperlocomotion in mice.
The effects of the D3-agonist (+/-)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) on morphine-induced hyperlocomotion were investigated in mice. 7-OH-DPAT (0.01-0.3 mg/kg s.c.) alone did not produce a significant locomotor activity in mice. Treatment with low doses of 7-OH-DPAT (0.1 and 0.3 mg/kg s.c.) attenuated morphine (10 and 20 mg/kg s.c.)-induced hyperlocomotion. The significant morphine-induced increase in dopamine (DA) metabolite levels, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the limbic forebrain (nucleus accumbens and olfactory tubercle) was suppressed by 7-OH-DPAT. These results suggest that activation of the D3-receptor in the mesolimbic dopamine system may attenuate the expression of morphine-induced hyperlocomotion.
Suzuki
T
T
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
Maeda
J
J
Funada
M
M
Misawa
M
M
D000818:Animals; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009043:Motor Activity; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D018491:Dopamine Agonists; D013764:Tetrahydronaphthalenes; D009020:Morphine; C031349:7-hydroxy-2-N,N-dipropylaminotetralin