[Effect of centrally administrated substance P on the brain mesolimbic system activity in rats as measured by microdialysis].
Action of substance P on the contents of dopamine, dihydroxyphenylacetic acid and homovanillic acid in the nucleus accumbens of rats was investigated with microdialysis procedure. During 3 days, each animal daily received i.v. the saline (the 1st day), 0.1 mcg of substance P (the 2nd day), 1 mcg of substance P (the 3rd day). Elevation of accumbal dopamine was observed amounting up to 41% and 71% for 0.1 mcg and 1 mcg of substance P, resp. Rates and duration of these changes also depended on neuropeptide concentration. 1 mcg of substance P produced the dopamine elevation with a peak by the 50th min. Moreover, in 75 min. after infusion of the neuropeptide, the levels of dopamine still remained increased. Response of metabolites also proved to be dose-related. With 1 mcg of substance P, the contents of dihydroxyphenylacetic acid increased by 28%, while with 0.1 mcg of substance P, this parameter did not change. Contents of homovanillie acid was unaffected by central substance P at the above doses. The data obtained corroborate the assumption of influence of the substance P on the reward system arising from its dopaminergic properties and provide a possible explanation of the neuropeptide effects observed in the conditioned place preference paradigm.
Nikolaev
S V
SV
Institute of the Human Brain, Russian Acad. Sci., St. Petersburg, 197376, Acad. Pavlov St., 12a, Russia.
Lebedev
A A
AA
Bychkov
E P
EP
Obliapin
A V
AV
Dambinova
S A
SA
Shabanov
P D
PD
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006719:Homovanillic Acid / Q000378:metabolism; D007276:Injections, Intraventricular; D008032:Limbic System / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000008:administration & dosage / Q000494:pharmacology*
D015102:3,4-Dihydroxyphenylacetic Acid; D013373:Substance P; D004298:Dopamine; D006719:Homovanillic Acid
Vliianie substantsii P posle ee tsentral'nogo vvedeniia na aktivnost' mezolimbicheskoĭ sistemy mozga krysy, po dannym mikrodializa.