L-DOPA inhibits spontaneous acetylcholine release from the striatum of experimental Parkinson's model rats.
Acetylcholine (ACh) release was measured by microdialysis. Addition of 10 nM L-DOPA to the perfusate significantly decreased ACh release, from the striatum of rats lesioned with 6-hydroxydopamine (6-OHDA), but not sham-operated rats. The L-DOPA-induced decrease was not affected by (-)-sulpiride which completely blocked D2- and D3-agonist-induced decrease in ACh release in lesioned rats. Neither 10 nM D-DOPA nor 100 nM dopamine caused by any change in ACh release. These findings suggest that L-DOPA-sensitive mechanisms are supersensitized in Parkinson's disease model rats.
Ueda
H
H
Department of Pharmacology, Yokohama City University School of Medicine, Japan.
Sato
K
K
Okumura
F
F
Misu
Y
Y
D000109:Acetylcholine / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D004195:Disease Models, Animal; D018491:Dopamine Agonists / Q000494:pharmacology*; D004357:Drug Synergism; D004873:Ergolines / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D016627:Oxidopamine / Q000494:pharmacology*; D010302:Parkinson Disease, Secondary / Q000378:metabolism*; D019257:Quinpirole; D051381:Rats; D017207:Rats, Sprague-Dawley; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D018491:Dopamine Agonists; D004873:Ergolines; D013764:Tetrahydronaphthalenes; D019257:Quinpirole; D007980:Levodopa; D016627:Oxidopamine; D000109:Acetylcholine; C031349:7-hydroxy-2-N,N-dipropylaminotetralin