Effect of pilocarpine on striatal acetylcholine release in dopamine-depleted rats.
We have previously demonstrated that the systemic administration of pilocarpine stimulates striatal acetylcholine (ACh) release in rats using a brain microdialysis technique. In the present study, we investigated whether a nigro-striatal dopaminergic system is involved in the pilocarpine-induced increase in striatal ACh release using dopamine-depleted rats under urethane anesthesia. The application of pilocarpine (0.1-10 mM) via the microdialysis tube increased striatal ACh release in normal rats in a concentration-dependent manner, but it had no effect on the release of glutamate or gamma-aminobutyric acid (GABA) from the striatum. The increase in striatal ACh release caused by pilocarpine (1 mM) was enhanced by reserpine and alpha-methyl-p-tyrosine treatment, which completely depleted dopamine in the striatum. These results suggest that pilocarpine selectively increases striatal ACh release by acting at the striatum, and that the nigro-striatal dopaminergic neurons play an inhibitory role in the pilocarpine-induced ACh release.
Murakami
Y
Y
Department of Pharmacology, Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Toyama-shi, Japan.
Matsumoto
K
K
Watanabe
H
H
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000502:physiology*; D018698:Glutamic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D018721:Muscarinic Agonists / Q000494:pharmacology*; D010862:Pilocarpine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018721:Muscarinic Agonists; D010862:Pilocarpine; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D000109:Acetylcholine; D004298:Dopamine