The Experts below are selected from a list of 990 Experts worldwide ranked by ideXlab platform
Hideomi Fuduka - One of the best experts on this subject based on the ideXlab platform.
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amphetamine antagonistic properties of 4 phenyl 1 2 3 4 tetrahydroisoquinoline inhibition of spinal reflex enhancing effects of methamphetamine phenylethylamine and Nomifensine
1991Co-Authors: Hideki Ono, Yasushi Hasebe, Mitsutoshi Satoh, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Hideomi FudukaAbstract:Abstract The antagonistic effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) against S(+)-methamphetamine, phenylethylamine and Nomifensine were studied by measurement of spinal monosynaptic reflex potential (MSR). S(+)-Methamphetamine, phenylethylamine and Nomifensine enhanced the amplitude of MSR in C1-spinalized rats through release of noradrenaline from the terminals of descending fibers and consequent activation of α1-adrenoceptors. Although 4PTIQ alone did not change the amplitude of the MSR, 4PTIQ inhibited the enhancement of MSR induced by S(+)-methamphetamine and related compounds. The MSR of rats with an intact spinal cord was enhanced by conditioning stimulation of the ipsilateral locus ceruleus. The MSR enhancement produced by the stimulation was blocked by prazosin but unaffected by 4PTIQ, showing that 4PTIQ does not have an α1-blocking action. These results suggest that the antagonistic effects of 4PTIQ on MSR enhancement by S(+)-methamphetamine, phenylethylamine and Nomifensine are due to its blocking of noradrenaline release produced by these amphethamine-like agents.
Nobuyoshi Nishiyama - One of the best experts on this subject based on the ideXlab platform.
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pretreatment with Nomifensine or Nomifensine analogue 4 phenyl 1 2 3 4 tetrahydroisoquinoline augments methamphetamine induced stereotypical behavior in mice
2012Co-Authors: Junichi Kitanaka, Nobue Kitanaka, Scott F Hall, George R Uhl, Hiromi Asano, Ryuki Chatani, Sachiko Hayata, Hiroko Yokoyama, Koh Ichi Tanaka, Nobuyoshi NishiyamaAbstract:Nomifensine is a dopamine/norepinephrine reuptake inhibitor. Nomifensine and some of its structural analogues produce behavioral effects indicative of indirect dopaminergic agonist properties, such as hyperlocomotion. By contrast, the deaminated and demethylated Nomifensine analogue 4-phenyl-1,2,3,4-tetrahydroisoquinoline (PTIQ) is reported to have amphetamine-antagonistic properties, as demonstrated by inhibition of methamphetamine (METH)-induced dopamine release in the nucleus accumbens and METH-induced hyperlocomotion in rats. In the present study, we examined the effect of PTIQ (10mg/kg, i.p.) and Nomifensine (3mg/kg, i.p.) on METH (5 or 10mg/kg, i.p.)-induced stereotypical behavior in mice in order to determine whether PTIQ and Nomifensine inhibit and augment, respectively, METH-induced stereotypical behavior. Unexpectedly, our observations demonstrated that both PTIQ and Nomifensine significantly augmented METH-induced stereotypical behavior and locomotion in mice. This augmentation is likely the result of additive effects on dopaminergic function by METH in combination with PTIQ or Nomifensine. These results suggest that, contrary to some reports, PTIQ may display dopaminergic agonist properties in mice.
Taku Nagao - One of the best experts on this subject based on the ideXlab platform.
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4 phenyltetrahydroisoquinoline but not Nomifensine or cocaine inhibits methamphetamine induced dopamine release
1993Co-Authors: Michihiro Tateyama, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Ono HidekiAbstract:Abstract The inhibitory effect of 4-phenyltetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced dopamine release in the rat nucleus accumbens was investigated using a brain microdialysis method. Methamphetamine (10 −6 M) infusion through a microdialysis probe induced the release of dopamine. Although the uptake inhibitors, cocaine (3×10 −6 M) and Nomifensine (10 −6 M), failed to block dopamine release, 4-PTIQ (10 −6 M) inhibited the dopamine-releasing effect of methamphetamine. 4-PTIQ did not affect the elevation of the extracellular dopamine level induced by high concentrations of Nomifensine (10 −5 M) and cocaine (3×10 −5 M). 4-PTIQ was the weakest inhibitor of [ 3 H]dopamine uptake by rat striatal synaptosomes. These results suggest that 4-PTIQ is a selective antagonist against the dopamine-releasing effect of methamphetamine in the nucleus accumbens.
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amphetamine antagonistic properties of 4 phenyl 1 2 3 4 tetrahydroisoquinoline inhibition of spinal reflex enhancing effects of methamphetamine phenylethylamine and Nomifensine
1991Co-Authors: Hideki Ono, Yasushi Hasebe, Mitsutoshi Satoh, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Hideomi FudukaAbstract:Abstract The antagonistic effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) against S(+)-methamphetamine, phenylethylamine and Nomifensine were studied by measurement of spinal monosynaptic reflex potential (MSR). S(+)-Methamphetamine, phenylethylamine and Nomifensine enhanced the amplitude of MSR in C1-spinalized rats through release of noradrenaline from the terminals of descending fibers and consequent activation of α1-adrenoceptors. Although 4PTIQ alone did not change the amplitude of the MSR, 4PTIQ inhibited the enhancement of MSR induced by S(+)-methamphetamine and related compounds. The MSR of rats with an intact spinal cord was enhanced by conditioning stimulation of the ipsilateral locus ceruleus. The MSR enhancement produced by the stimulation was blocked by prazosin but unaffected by 4PTIQ, showing that 4PTIQ does not have an α1-blocking action. These results suggest that the antagonistic effects of 4PTIQ on MSR enhancement by S(+)-methamphetamine, phenylethylamine and Nomifensine are due to its blocking of noradrenaline release produced by these amphethamine-like agents.
Masaaki Hirobe - One of the best experts on this subject based on the ideXlab platform.
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4 phenyltetrahydroisoquinoline but not Nomifensine or cocaine inhibits methamphetamine induced dopamine release
1993Co-Authors: Michihiro Tateyama, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Ono HidekiAbstract:Abstract The inhibitory effect of 4-phenyltetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced dopamine release in the rat nucleus accumbens was investigated using a brain microdialysis method. Methamphetamine (10 −6 M) infusion through a microdialysis probe induced the release of dopamine. Although the uptake inhibitors, cocaine (3×10 −6 M) and Nomifensine (10 −6 M), failed to block dopamine release, 4-PTIQ (10 −6 M) inhibited the dopamine-releasing effect of methamphetamine. 4-PTIQ did not affect the elevation of the extracellular dopamine level induced by high concentrations of Nomifensine (10 −5 M) and cocaine (3×10 −5 M). 4-PTIQ was the weakest inhibitor of [ 3 H]dopamine uptake by rat striatal synaptosomes. These results suggest that 4-PTIQ is a selective antagonist against the dopamine-releasing effect of methamphetamine in the nucleus accumbens.
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amphetamine antagonistic properties of 4 phenyl 1 2 3 4 tetrahydroisoquinoline inhibition of spinal reflex enhancing effects of methamphetamine phenylethylamine and Nomifensine
1991Co-Authors: Hideki Ono, Yasushi Hasebe, Mitsutoshi Satoh, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Hideomi FudukaAbstract:Abstract The antagonistic effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) against S(+)-methamphetamine, phenylethylamine and Nomifensine were studied by measurement of spinal monosynaptic reflex potential (MSR). S(+)-Methamphetamine, phenylethylamine and Nomifensine enhanced the amplitude of MSR in C1-spinalized rats through release of noradrenaline from the terminals of descending fibers and consequent activation of α1-adrenoceptors. Although 4PTIQ alone did not change the amplitude of the MSR, 4PTIQ inhibited the enhancement of MSR induced by S(+)-methamphetamine and related compounds. The MSR of rats with an intact spinal cord was enhanced by conditioning stimulation of the ipsilateral locus ceruleus. The MSR enhancement produced by the stimulation was blocked by prazosin but unaffected by 4PTIQ, showing that 4PTIQ does not have an α1-blocking action. These results suggest that the antagonistic effects of 4PTIQ on MSR enhancement by S(+)-methamphetamine, phenylethylamine and Nomifensine are due to its blocking of noradrenaline release produced by these amphethamine-like agents.
Shigeru Ohta - One of the best experts on this subject based on the ideXlab platform.
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4 phenyltetrahydroisoquinoline but not Nomifensine or cocaine inhibits methamphetamine induced dopamine release
1993Co-Authors: Michihiro Tateyama, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Ono HidekiAbstract:Abstract The inhibitory effect of 4-phenyltetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced dopamine release in the rat nucleus accumbens was investigated using a brain microdialysis method. Methamphetamine (10 −6 M) infusion through a microdialysis probe induced the release of dopamine. Although the uptake inhibitors, cocaine (3×10 −6 M) and Nomifensine (10 −6 M), failed to block dopamine release, 4-PTIQ (10 −6 M) inhibited the dopamine-releasing effect of methamphetamine. 4-PTIQ did not affect the elevation of the extracellular dopamine level induced by high concentrations of Nomifensine (10 −5 M) and cocaine (3×10 −5 M). 4-PTIQ was the weakest inhibitor of [ 3 H]dopamine uptake by rat striatal synaptosomes. These results suggest that 4-PTIQ is a selective antagonist against the dopamine-releasing effect of methamphetamine in the nucleus accumbens.
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amphetamine antagonistic properties of 4 phenyl 1 2 3 4 tetrahydroisoquinoline inhibition of spinal reflex enhancing effects of methamphetamine phenylethylamine and Nomifensine
1991Co-Authors: Hideki Ono, Yasushi Hasebe, Mitsutoshi Satoh, Taku Nagao, Shigeru Ohta, Masaaki Hirobe, Hideomi FudukaAbstract:Abstract The antagonistic effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) against S(+)-methamphetamine, phenylethylamine and Nomifensine were studied by measurement of spinal monosynaptic reflex potential (MSR). S(+)-Methamphetamine, phenylethylamine and Nomifensine enhanced the amplitude of MSR in C1-spinalized rats through release of noradrenaline from the terminals of descending fibers and consequent activation of α1-adrenoceptors. Although 4PTIQ alone did not change the amplitude of the MSR, 4PTIQ inhibited the enhancement of MSR induced by S(+)-methamphetamine and related compounds. The MSR of rats with an intact spinal cord was enhanced by conditioning stimulation of the ipsilateral locus ceruleus. The MSR enhancement produced by the stimulation was blocked by prazosin but unaffected by 4PTIQ, showing that 4PTIQ does not have an α1-blocking action. These results suggest that the antagonistic effects of 4PTIQ on MSR enhancement by S(+)-methamphetamine, phenylethylamine and Nomifensine are due to its blocking of noradrenaline release produced by these amphethamine-like agents.