Modulation of [3H]dopamine release by neuropeptide Y in rat striatal slices.
Neuropeptide Y, a 36-amino-acid peptide, has a wide and specific distribution in the central nervous system. In this study we examined the regulatory mechanisms of neuropeptide Y on dopamine release in the rat central nervous system. The effects of neuropeptide Y on the electrically stimulated [3H]dopamine release were investigated in superfused striatal slices of Sprague-Dawley rats, spontaneously hypertensive rats and Wistar-Kyoto rats. Neuropeptide Y (1 x 10(-8) - 1 x 10(-7) mol/1) reduced the stimulation (1 Hz)-induced [3H]dopamine release by a comparable amount in Sprague-Dawley rats. The blockade of dopamine D2 receptors by the dopamine D2 receptor antagonist, sulpiride, diminished the inhibitory effects of neuropeptide Y on the stimulation-evoked [3H]dopamine release. Pretreatment of slices with pertussis toxin (a potent inhibitor of G1-proteins) attenuated the suppression of the stimulation-evoked [3H]dopamine release by neuropeptide Y. Unlabelled dopamine itself reduced the stimulation-evoked [3H]dopamine release, and the inhibitory effect was also attenuated in the pertussis toxin-pretreated slices. In spontaneously hypertensive rats, the inhibitory effect of neuropeptide Y on the stimulation-evoked [3H]dopamine release was more pronounced than that in Wistar-Kyoto rats. The results of the present study showed that neuropeptide Y inhibited the stimulation-evoked dopamine release partially mediated by dopamine D2 receptors and the pertussis toxin-sensitive G1-proteins in rat striatum. Furthermore, the greater effect of neuropeptide Y on dopamine release in spontaneously hypertensive rats suggests a possible involvement of the peptide in regulating the central dopaminergic nerve activity in hypertension.
Tsuda
K
K
Department of Medicine, Wakayama Medical College, Japan.
Tsuda
S
S
Nishio
I
I
Goldstein
M
M
Masuyama
Y
Y
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004558:Electric Stimulation; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D009478:Neuropeptide Y / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D037342:Pertussis Toxin; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D013045:Species Specificity; D013469:Sulpiride / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000633:toxicity
D018492:Dopamine Antagonists; D009478:Neuropeptide Y; D010566:Virulence Factors, Bordetella; D013469:Sulpiride; D037342:Pertussis Toxin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D004298:Dopamine