6R-tetrahydrobiopterin perfusion enhances dopamine, serotonin, and glutamate outputs in dialysate from rat striatum and frontal cortex.
The effect of 6R-tetrahydrobiopterin (R-THBP) on neurotransmitter release was investigated using in vivo brain microdialysis in urethane-anesthetized rats. Perfusion of 1.0 mM R-THBP enhanced the level of dopamine output in dialysates collected from the striatum and frontal cortex. R-THBP perfusion also increased serotonin (striatum) and glutamate outputs (striatum and frontal cortex). Dopaminergic terminals in the striatum were destroyed unilaterally by continuous infusion of 6-hydroxydopamine (6-OHDA) using an osmotic minipump system. The effect of R-THBP administration on glutamate level was found to be almost completely suppressed in the 6-OHDA-lesioned side of striatum, while in the intact side of striatum the glutamate level in the dialysates responded normally to R-THBP perfusion. These results suggest that R-THBP may play a role in the mechanisms of release of dopamine, serotonin, and glutamate. The functioning of the catecholaminergic system probably mediates the increase in glutamate output due to R-THBP perfusion.
Department of Neuroscience, Osaka Bioscience Institute, Japan.
N
N
Mataga
K
K
Imamura
Y
Y
Watanabe
D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives* / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D005625:Frontal Lobe / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D008297:Male; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D005971:Glutamates; D001708:Biopterins; D012701:Serotonin; D018698:Glutamic Acid; C003402:sapropterin; D004298:Dopamine