Effects of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin on the dopaminergic and cholinergic receptors as evaluated by positron emission tomography in the Rhesus monkey

  title={Effects of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin on the dopaminergic and cholinergic receptors as evaluated by positron emission tomography in the Rhesus monkey},
  author={Yoshihiro Tani and Takafumi Ishihara and Tadashi Kanai and Tomochika Ohno and Jesper L. R. Andersson and A. Lilja and Gunnar Antoni and Karl Johan Fasth and Peter Bjurling and G{\"o}ran Westerberg and Per Hartvig and Hirotaka Onoe and Y. Watanabe and Bengt L{\aa}ngstr{\"o}m},
  journal={Journal of Neural Transmission / General Section JNT},
The effects of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) on the central cholinergic and dopaminergic systems in the Rhesus monkey brain were investigated by positron emission tomography (PET) with the muscarinic cholinergic receptor ligands (N-[11C]methyl-benztropine) and dopaminergic receptor ligands selective for D1 D2, and D3 subtypes ([11C]SCH23390, N-[11C]methyl-spiperone, and (+)[11C]UH232, respectively). None of the doses (3, 10, and 30 mg/kg i.v.) of R-THBP used significantly… Expand
Improvement by repeated administration of 6R-tetrahydrobiopterin of 5,7-dihydroxytryptamine-induced abnormal behaviors in immature rats.
It is suggested that the behavioral restoration by 6R-BH(4) might be due to the enhancement of 5-HT turnover by accumulated but not a single dose of 6R,6,7,8-tetrahydrobiopterin. Expand
Radioligands for the dopamine receptor subtypes.
This special issue subchapter provides a summary of the most important (18) F- labeled and (11) C-labeled radioligands for PET imaging of the dopamine receptor subtypes, their radiochemistry, and characteristics from in vitro and in vivo applications, considering not only the already established PET ligands but also the recently published preclinical work. Expand
PET Measurement of rCBF in the presence of a neurochemical tracer
A dual tracer positron emission tomography (PET) technique is presented here to extend functional neurochemical imaging studies by simultaneously measuring changes in regional cerebral blood flow (rCBF) to permit correlations of task or drug induced changes in rCBF and neurochemical function. Expand


6R-L-erythro-5,6,7,8-tetrahydrobiopterin as a regulator of dopamine and serotonin biosynthesis in the rat brain.
6R-BH4 concentration may be submaximal within DA and 5-HT neurons, and that an increase in 6R- BH4 in the brain enhances the biosyntheses of DA and5-HT, according to the results. Expand
Molecular Mechanisms of Tetrahydrobiopterin Action on Neurotransmitter Release
6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) is a common cofactor for phenylalanine, tyrosine, and tryptophan hydroxylases, the latter two of which are the rate-limiting enzymes ofExpand
Enhancement of acetylcholine release in the hippocampus by 6R-L-erythro-5,6,7,8-tetrahydrobiopterin is mediated by 5-hydroxytryptamine
The results suggest that 6R-BH4 stimulates A choline release in the hippocampus, mainly by augmenting release of 5-HT, a potent stimulator of ACh release, and partly by augmented release of DA. Expand
The effects of kainic acid and 6-hydroxydopamine lesions, metal ions and GTP on in vitro binding of the D-2 dopamine agonist, [3H]N-0437, to striatal membranes.
The results suggest that [3H]N-0437 labels both pre- and post Synaptic receptors, although postsynaptic receptors are labelled preferentially, and there is an indication that GTP shifts the affinity state of the D-2 receptor from high to low, while Na+ seems to be an allosteric inhibitor. Expand
Monoamine-mediated enhancement of acetylcholine release in rat hippocampus by 6R-l-erythro-5, 6, 7, 8-tetrahydrobiopterin
The results show that 6R-BH4 stimulates exocytotic ACh release in the hippocampus through action on a local monoaminergic system in the hippocampal region of rats pretreated with reserpine to deplete monoamines. Expand
The enantiomers of the D-2 dopamine receptor agonist N-0437 discriminate between pre- and postsynaptic dopamine receptors.
The results indicate that (-)N-0437 is very selective for the stimulation of postsynaptic dopamine receptors, while (+)N -0437 stimulates presynaptic dopaminergic receptors and blocks post Synaptic receptors. Expand
In vivo binding of 3H-N-methylspiperone to dopamine and serotonin receptors.
3H-N-methylspiperone results in a much higher specific/nonspecific binding ratio in the striatum and frontal cortex and displays more than a two-fold higher brain uptake. Expand
3H-3-N-methylspiperone labels D2 dopamine receptors in basal ganglia and S2 serotonin receptors in cerebral cortex
  • R. A. Lyon, M. Titeler, +6 authors M. Kuhar
  • Chemistry, Medicine
  • The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1986
Kinetic studies revealed a very rapid rate of association in all the tissues studied and the rate of dissociation was relatively slow in all 4 tissue preparations; the dissociation rate was somewhat slower in rat striatum and human caudate relative to rat and human frontal cortex. Expand
6R-tetrahydrobiopterin perfusion enhances dopamine, serotonin, and glutamate outputs in dialysate from rat striatum and frontal cortex
Results suggest that R-THBP may play a role in the mechanisms of release of dopamine, serotonin, and glutamate in urethane-anesthetized rats and the functioning of the catecholaminergic system probably mediates the increase in glutamate output due to R- THBP perfusion. Expand
Human dopamine receptor subtypes—in vitro binding analysis using3H-SCH 23390 and3H-raclopride
The distribution of the dopamine receptor subtypes obtained in the present in vitro investigation is in agreement with data obtained with 11C-SCH 23390 and11C-raclopride in positron emission tomographic studies in human volunteers. Expand