Endothelin-3 modification of dopamine release in anaesthetised rat striatum; an in vivo microdialysis study.
Endothelin-3 (ET-3), a member of the vasoconstrictive peptide family, has recently been recognized as a neuropeptide. We used brain microdialysis and on-line HPLC to examine the effect of ET-3 on the basal outflow of monoamines and their metabolites in the ketamine-anaesthetised rat striatum in vivo. Although intrastriatal infusion of ET-3 (40 pmol/rat) did not change basal dopamine (DA) release, after perfusion of DA releasing agent (5 x 10(-5) M ouabain or 120 mM KCl), ET-3 could increase the DA level. Further, these effects of ET-3 were attenuated by calcium-free Ringer. These data indicated that ET-3 may act by modifying the exocytosis from the striatum of rat brain to enhance DA release after depolarization induced by an agent such as KCl or ouabain.
Konya
H
H
2nd Department of Internal Medicine, Hyogo College of Medicine, Japan.
Nagai
K
K
Masuda
H
H
Kakishita
E
E
D000588:Amines / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D016232:Endothelins / Q000502:physiology*; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010477:Perfusion; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011921:Rats, Inbred WKY
D000588:Amines; D016232:Endothelins; D010042:Ouabain; D011189:Potassium Chloride; D004298:Dopamine