Intranigral injection of selective neurokinin-1 and neurokinin-3 but not neurokinin-2 receptor agonists biphasically modulate striatal dopamine metabolism but not striatal preprotachykinin-A mRNA in the rat.
Tachykinins are highly concentrated in striatum and substantia nigra. Intranigral injection of selective neurokinin-1 and neurokinin-3 but not neurokinin-2 receptor agonists significantly decreased striatal dopamine metabolism at early time points (1 and 5 min) but increased dopamine metabolism at late time points (60 and 180 min). This probably modified striatal dopamine release, was, however, not able to influence striatal preprotachykinin-A gene expression. The data suggest that tachykinins modulate nigro-striatal dopamine neurons via neurokinin-1 and neurokinin-3 receptors and the modified dopamine stimulus is not strong enough to influence striatal tachykinin neurons.
Humpel
C
C
Department of Psychiatry, University Hospital, Innsbruck, Austria.
Saria
A
A
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D007267:Injections; D015288:Neurokinin A / Q000031:analogs & derivatives* / Q000494:pharmacology; D015287:Neurokinin B / Q000031:analogs & derivatives* / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000187:drug effects*; D018041:Receptors, Neurokinin-2 / Q000187:drug effects*; D018042:Receptors, Neurokinin-3 / Q000187:drug effects*; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism; D015320:Tachykinins / Q000096:biosynthesis* / Q000235:genetics
D010446:Peptide Fragments; D011498:Protein Precursors; D012333:RNA, Messenger; D018040:Receptors, Neurokinin-1; D018041:Receptors, Neurokinin-2; D018042:Receptors, Neurokinin-3; D015320:Tachykinins; C080394:neurokinin B, MePhe(7)-; C044206:preprotachykinin; D015102:3,4-Dihydroxyphenylacetic Acid; C062618:substance P, Sar(9)-Met(O2)(11)-; C064218:neurokinin A (4-10), beta-Ala(8)-; D013373:Substance P; D015288:Neurokinin A; D015287:Neurokinin B; D004298:Dopamine