An investigation into the effects of apomorphine on the release of acetylcholine in the striatum of freely-moving rat using in vivo microdialysis.
1. Using in vivo microdialysis, we studied the effects of apomorphine on the release of acetylcholine (ACh) in the striatum of freely-moving rats. 2. Basal release of ACh was 3.01 +/- 0.51 pmol/15 min in 30 microliters (containing of 10 microM neostigmine) of the striatal perfusate. 3. Ringer containing tetrodotoxin (1 microM), hemicholinium-3 (5 mM), or Ca(2+)-free Ringer was perfused into the striatum. Each of these treatments produced a significant attenuation in release content of ACh. High K+ (30 mM) produced a significant increase in ACh release. 4. In normal rats, apomorphine (0.05 mg/kg, s.c.) increased striatal ACh release. A high dose (1.0 mg/kg) significantly attenuated release. 5. In 6-OHDA-pretreated rats, although the lower dose of apomorphine did not increase striatal ACh release, the high dose produced a more significant attenuation of release. 6. It is concluded that apomorphine enhanced or attenuated the striatal ACh release and that this effect was regulated by nigro-striatal dopaminergic system in the freely moving rats.
Hagiwara
Y
Y
Department of Pharmacology, Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Taguchi
K
K
Atobe
J
J
Suzuki
Y
Y
Kubo
T
T
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology; D007279:Injections, Subcutaneous; D008297:Male; D017551:Microdialysis; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D001058:Apomorphine; D000109:Acetylcholine; D004298:Dopamine