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Liisa Ahtee - One of the best experts on this subject based on the ideXlab platform.

  • Locally infused taurine, GABA and Homotaurine alter differently the striatal extracellular concentrations of dopamine and its metabolites in rats
    Amino Acids, 1998
    Co-Authors: M. Ruotsalainen, M. Majasaari, J. Salimäki, Liisa Ahtee
    Abstract:

    We studied in vivo the effects of locally infused taurine (50, 150, and 450 mM) on the striatal dopamine and its metabolites in comparison with those of GABA and Homotaurine, a GABA_A receptor agonist, in freely moving rats. The extracellular dopamine concentration was elevated maximally 2.5-, 2- and 4-fold by taurine, GABA and Homotaurine, respectively. At 150 mM concentration, at which the maximum effects occurred, Homotaurine increased the extracellular dopamine more than taurine or GABA. When taurine and GABA were infused simultaneously with tetrodotoxin the output of dopamine did not differ from that in the presence of tetrodotoxin alone. In comparison, tetrodotoxin did not inhibit the increase in extracellular dopamine caused by Homotaurine. Furthermore, omission of calcium from the perfusion fluid inhibited the increase of extracellular dopamine caused by GABA. However, it did not block the increase of dopamine caused by taurine or Homotaurine. The present study suggests that the effects of intrastriatal taurine, GABA and Homotaurine on the striatal extracellular dopamine differ. Thus, these amino acids seem to affect the striatal dopaminergic neurons via more than one mechanism.

  • Effects of taurine, Homotaurine and GABA on hypothalamic and striatal dopamine metabolism
    Naunyn-Schmiedeberg's Archives of Pharmacology, 1992
    Co-Authors: Elina Panula-lehto, Minna Mäkinen, Liisa Ahtee
    Abstract:

    To elucidate the effects of taurine on hypothalamic and striatal dopaminergic neurotransmission we compared its effects to those of γ-aminobutyric acid (GABA) and Homotaurine (a GABA_A-receptor agonist) on hypothalamic and striatal concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and, in the case of striatum, 3-methoxytyramine (3-MT) in rats. In addition, hypothalamic and striatal 5-hydroxytryptamine (5-HT) und 5-hydroxyindoleacetic acid, hypothalamic noradrenaline (NA) and 3-methoxy-4-hydroxyphenylglycol sulfate, and pituitary DA concentrations were also measured. The amino acids were injected into the lateral brain ventricles of conscious male rats in doses of 10 and 36 μmol/rat, and rat were sacrificed 15 and 60 min later, respectively. Homotaurine (by 11010) but not the other two amino acids elevated striatal DA, whereas hypothalamic DA was increased by both taurine (36%) and Homotaurine (31%). All three amino acids at 36 μmol elevated striatal DOPAC, Homotaurine (51%) more than taurine (31%) or GABA (30%), and hypothalamic DOPAC, both taurine (102%) and Homotaurine (82%) clearly more than GABA (34%). Neither striatal nor hypothalamic HVA was altered by any of the amino acids. At 10 μmol the amino acids decreased striatal 3-MT by about 40%. At 36 μmol taurine and Homotaurine reduced 3-MT by about 70%, whereas increasing the dose of GABA did not further reduce 3-MT. Both taurine and Homotaurine at 36 μmol decreased hypothalamic NA content. Neither hypothalamic nor striatal 5-HT metabolism was altered. In the neurointermediate lobe of the pituitary gland taurine at 10 μmol but not at 36 μmol slightly (20%) increased DA. These results show that taurine and Homotaurine clearly alter the hypothalamic DA metabolism, and give further support to the suggestion that taurine and Homotaurine similarly to GABA reduce the release of DA in the striatum. Homotaurine seems to alter the striatal DA metabolism more effectively than taurine or GABA. On the other hand, hypothalamic DA seems to be equally sensitive to taurine and Homotaurine, and is clearly less sensitive to GABA. The pronounced elevation of hypothalamic DA and DOPAC after taurine and Homotaurine could be related to changes in hypothalamic NA.

  • Effects of taurine, Homotaurine and GABA on hypothalamic and striatal dopamine metabolism
    Naunyn-Schmiedeberg's archives of pharmacology, 1992
    Co-Authors: Elina Panula-lehto, Minna Mäkinen, Liisa Ahtee
    Abstract:

    To elucidate the effects of taurine on hypothalamic and striatal dopaminergic neurotransmission we compared its effects to those of γ-aminobutyric acid (GABA) and Homotaurine (a GABAA-receptor agonist) on hypothalamic and striatal concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and, in the case of striatum, 3-methoxytyramine (3-MT) in rats. In addition, hypothalamic and striatal 5-hydroxytryptamine (5-HT) und 5-hydroxyindoleacetic acid, hypothalamic noradrenaline (NA) and 3-methoxy-4-hydroxyphenylglycol sulfate, and pituitary DA concentrations were also measured. The amino acids were injected into the lateral brain ventricles of conscious male rats in doses of 10 and 36 μmol/rat, and rat were sacrificed 15 and 60 min later, respectively.

S. Poenaru - One of the best experts on this subject based on the ideXlab platform.

  • effects of muscimol or Homotaurine on sleep wake states in alcohol dependent rats during withdrawal
    Pharmacology Biochemistry and Behavior, 1998
    Co-Authors: Saïd Rouhani, O Bajenaru, E. Emmanouilidis, G. Tran, R. Manicom, J Dallavasantucci, A T Dinhxuan, S. Poenaru
    Abstract:

    Abstract Sleep–wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. In the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received Homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg). The results have been compared with a control group of 36 rats that received water during the treatement phase of the experiment, and the 14th day received intraperitoneal muscimol or Homotaurine. Muscimol significantly improves the alterations of sleep–wake states in alcohol-withdrawn rats, decreasing the percentage of active wakefulness and increasing the percentage of REMS, but without any action on the latency of appearance of REMS, which remains shortened. The effects of Homotaurine are less important on the wakefulness, but it also increases the percentage of REMS without influencing its latency of appearance. The influence of these GABA A agonists is not identical during the whole period of survey in the light phase, as there are important differences in the temporal sequences for each of them. We conclude that the stimulation of GABA A receptors, of which the activity is decreased during alcohol withdrawal, significantly improves the disturbances in the sleep–wake states in the alcohol-dependent rats, in a time-related manner, and there are significant pharmacodynamic differences between muscimol and Homotaurine.

  • Effects of Muscimol or Homotaurine on Sleep–Wake States in Alcohol-Dependent Rats During Withdrawal
    Pharmacology biochemistry and behavior, 1998
    Co-Authors: Saïd Rouhani, J Dall'ava-santucci, O Bajenaru, E. Emmanouilidis, G. Tran, R. Manicom, Anh Tuan Dinh-xuan, S. Poenaru
    Abstract:

    Abstract Sleep–wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. In the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received Homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg). The results have been compared with a control group of 36 rats that received water during the treatement phase of the experiment, and the 14th day received intraperitoneal muscimol or Homotaurine. Muscimol significantly improves the alterations of sleep–wake states in alcohol-withdrawn rats, decreasing the percentage of active wakefulness and increasing the percentage of REMS, but without any action on the latency of appearance of REMS, which remains shortened. The effects of Homotaurine are less important on the wakefulness, but it also increases the percentage of REMS without influencing its latency of appearance. The influence of these GABA A agonists is not identical during the whole period of survey in the light phase, as there are important differences in the temporal sequences for each of them. We conclude that the stimulation of GABA A receptors, of which the activity is decreased during alcohol withdrawal, significantly improves the disturbances in the sleep–wake states in the alcohol-dependent rats, in a time-related manner, and there are significant pharmacodynamic differences between muscimol and Homotaurine.

  • Effects of alcohol dependence on shock-induced fighting: Action of muscimol and Homotaurine
    Pharmacology biochemistry and behavior, 1992
    Co-Authors: Saïd Rouhani, E. Emmanouilidis, G. Tran, C. Payan, A. Castresana, A. Soulairac, S. Poenaru
    Abstract:

    We have applied the electroshock-induced fighting behavior to the study of experimental alcohol dependence. Adult Wistar rats were intoxicated chronically with ethanol (10 g/kg/24 h) for 13 days. Electroshock-induced fighting behavior was studied during chronic intoxication and withdrawal in comparison with normal rats receiving a water-carbohydrate solution isocaloric to ethanol. Rats were divided into groups receiving respectively muscimol (0.25 mg/kg), a GABAA agonist; Homotaurine (140 mg/kg) a GABA mimetic; and physiological saline (10 ml/kg), intraperitoneally. During chronic intoxication, rats showed an increase in defensive-fighting behavior. Withdrawal accentuated the aggressive behavior and muscimol and Homotaurine inhibited it. These results confirm the relevance of the electroshock-induced defensive fighting behavior test in chronic intoxication with alcohol, but to show the involvement of GABAergic transmission in the behavioral effects of alcohol withdrawal, additional experiments with other GABA mimetics and with GABA antagonists should be considered.

Rosario Gulias-cañizo - One of the best experts on this subject based on the ideXlab platform.

  • Differential modulation of human GABAC-ρ1 receptor by sulfur-containing compounds structurally related to taurine.
    BMC Neuroscience, 2018
    Co-Authors: Martín González-andrade, Herminia Pasantes-morales, Rubén Zamora-alvarado, Hugo Quiroz-mercado, Roberto Gonzales-salinas, Rodrigo Franco, Edgar Zenteno, Rosario Gulias-cañizo
    Abstract:

    Background The amino acid taurine (2-Aminoethanesulfonic acid) modulates inhibitory neurotransmitter receptors. This study aimed to determine if the dual action of taurine on GABAC-ρ1R relates to its structure. To address this, we tested the ability of the structurally related compounds Homotaurine, hypotaurine, and isethionic acid to modulate GABAC-ρ1R.

  • Differential modulation of human GABA_C-ρ1 receptor by sulfur-containing compounds structurally related to taurine
    BMC Neuroscience, 2018
    Co-Authors: Lenin David Ochoa-de La Paz, Martín González-andrade, Herminia Pasantes-morales, Rubén Zamora-alvarado, Hugo Quiroz-mercado, Roberto Gonzales-salinas, Rodrigo Franco, Edgar Zenteno, Rosario Gulias-cañizo
    Abstract:

    Background The amino acid taurine (2-Aminoethanesulfonic acid) modulates inhibitory neurotransmitter receptors. This study aimed to determine if the dual action of taurine on GABA_C-ρ1R relates to its structure. To address this, we tested the ability of the structurally related compounds Homotaurine, hypotaurine, and isethionic acid to modulate GABA_C-ρ1R. Results In Xenopus laevis oocytes, hypotaurine and Homotaurine partially activate heterologously expressed GABA_C-ρ1R, showing an increment in its deactivation time with no changes in channel permeability, whereas isethionic acid showed no effect. Competitive assays suggest that hypotaurine and Homotaurine compete for the GABA-binding site. In addition, their effects were blocked by the ion-channel blockers picrotixin and Methyl(1,2,5,6-tetrahydropyridine-4-yl) phosphinic acid. In contrast to taurine, co-application of GABA with hypotaurine or Homotaurine revealed that the dual effect is present separately for each compound: hypotaurine modulates positively the GABA current, while Homotaurine shows a negative modulation, both in a dose-dependent manner. Interestingly, Homotaurine diminished hypotaurine-induced currents. Thus, these results strongly suggest a competitive interaction between GABA and Homotaurine or hypotaurine for the same binding site. “In silico” modeling confirms these observations, but it also shows a second binding site for Homotaurine, which could explain the negative effect of this compound on the current generated by GABA or hypotaurine, during co-application protocols. Conclusions The sulfur-containing compounds structurally related to taurine are partial agonists of GABA_C-ρ1R that occupy the agonist binding site. The dual effect is unique to taurine, whereas in the case of hypotaurine and Homotaurine it presents separately; hypotaurine increases and Homotaurine decreases the GABA current.

Elina Panula-lehto - One of the best experts on this subject based on the ideXlab platform.

  • Effects of taurine, Homotaurine and GABA on hypothalamic and striatal dopamine metabolism
    Naunyn-Schmiedeberg's Archives of Pharmacology, 1992
    Co-Authors: Elina Panula-lehto, Minna Mäkinen, Liisa Ahtee
    Abstract:

    To elucidate the effects of taurine on hypothalamic and striatal dopaminergic neurotransmission we compared its effects to those of γ-aminobutyric acid (GABA) and Homotaurine (a GABA_A-receptor agonist) on hypothalamic and striatal concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and, in the case of striatum, 3-methoxytyramine (3-MT) in rats. In addition, hypothalamic and striatal 5-hydroxytryptamine (5-HT) und 5-hydroxyindoleacetic acid, hypothalamic noradrenaline (NA) and 3-methoxy-4-hydroxyphenylglycol sulfate, and pituitary DA concentrations were also measured. The amino acids were injected into the lateral brain ventricles of conscious male rats in doses of 10 and 36 μmol/rat, and rat were sacrificed 15 and 60 min later, respectively. Homotaurine (by 11010) but not the other two amino acids elevated striatal DA, whereas hypothalamic DA was increased by both taurine (36%) and Homotaurine (31%). All three amino acids at 36 μmol elevated striatal DOPAC, Homotaurine (51%) more than taurine (31%) or GABA (30%), and hypothalamic DOPAC, both taurine (102%) and Homotaurine (82%) clearly more than GABA (34%). Neither striatal nor hypothalamic HVA was altered by any of the amino acids. At 10 μmol the amino acids decreased striatal 3-MT by about 40%. At 36 μmol taurine and Homotaurine reduced 3-MT by about 70%, whereas increasing the dose of GABA did not further reduce 3-MT. Both taurine and Homotaurine at 36 μmol decreased hypothalamic NA content. Neither hypothalamic nor striatal 5-HT metabolism was altered. In the neurointermediate lobe of the pituitary gland taurine at 10 μmol but not at 36 μmol slightly (20%) increased DA. These results show that taurine and Homotaurine clearly alter the hypothalamic DA metabolism, and give further support to the suggestion that taurine and Homotaurine similarly to GABA reduce the release of DA in the striatum. Homotaurine seems to alter the striatal DA metabolism more effectively than taurine or GABA. On the other hand, hypothalamic DA seems to be equally sensitive to taurine and Homotaurine, and is clearly less sensitive to GABA. The pronounced elevation of hypothalamic DA and DOPAC after taurine and Homotaurine could be related to changes in hypothalamic NA.

  • Effects of taurine, Homotaurine and GABA on hypothalamic and striatal dopamine metabolism
    Naunyn-Schmiedeberg's archives of pharmacology, 1992
    Co-Authors: Elina Panula-lehto, Minna Mäkinen, Liisa Ahtee
    Abstract:

    To elucidate the effects of taurine on hypothalamic and striatal dopaminergic neurotransmission we compared its effects to those of γ-aminobutyric acid (GABA) and Homotaurine (a GABAA-receptor agonist) on hypothalamic and striatal concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and, in the case of striatum, 3-methoxytyramine (3-MT) in rats. In addition, hypothalamic and striatal 5-hydroxytryptamine (5-HT) und 5-hydroxyindoleacetic acid, hypothalamic noradrenaline (NA) and 3-methoxy-4-hydroxyphenylglycol sulfate, and pituitary DA concentrations were also measured. The amino acids were injected into the lateral brain ventricles of conscious male rats in doses of 10 and 36 μmol/rat, and rat were sacrificed 15 and 60 min later, respectively.

Saïd Rouhani - One of the best experts on this subject based on the ideXlab platform.

  • effects of muscimol or Homotaurine on sleep wake states in alcohol dependent rats during withdrawal
    Pharmacology Biochemistry and Behavior, 1998
    Co-Authors: Saïd Rouhani, O Bajenaru, E. Emmanouilidis, G. Tran, R. Manicom, J Dallavasantucci, A T Dinhxuan, S. Poenaru
    Abstract:

    Abstract Sleep–wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. In the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received Homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg). The results have been compared with a control group of 36 rats that received water during the treatement phase of the experiment, and the 14th day received intraperitoneal muscimol or Homotaurine. Muscimol significantly improves the alterations of sleep–wake states in alcohol-withdrawn rats, decreasing the percentage of active wakefulness and increasing the percentage of REMS, but without any action on the latency of appearance of REMS, which remains shortened. The effects of Homotaurine are less important on the wakefulness, but it also increases the percentage of REMS without influencing its latency of appearance. The influence of these GABA A agonists is not identical during the whole period of survey in the light phase, as there are important differences in the temporal sequences for each of them. We conclude that the stimulation of GABA A receptors, of which the activity is decreased during alcohol withdrawal, significantly improves the disturbances in the sleep–wake states in the alcohol-dependent rats, in a time-related manner, and there are significant pharmacodynamic differences between muscimol and Homotaurine.

  • Effects of Muscimol or Homotaurine on Sleep–Wake States in Alcohol-Dependent Rats During Withdrawal
    Pharmacology biochemistry and behavior, 1998
    Co-Authors: Saïd Rouhani, J Dall'ava-santucci, O Bajenaru, E. Emmanouilidis, G. Tran, R. Manicom, Anh Tuan Dinh-xuan, S. Poenaru
    Abstract:

    Abstract Sleep–wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. In the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received Homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg). The results have been compared with a control group of 36 rats that received water during the treatement phase of the experiment, and the 14th day received intraperitoneal muscimol or Homotaurine. Muscimol significantly improves the alterations of sleep–wake states in alcohol-withdrawn rats, decreasing the percentage of active wakefulness and increasing the percentage of REMS, but without any action on the latency of appearance of REMS, which remains shortened. The effects of Homotaurine are less important on the wakefulness, but it also increases the percentage of REMS without influencing its latency of appearance. The influence of these GABA A agonists is not identical during the whole period of survey in the light phase, as there are important differences in the temporal sequences for each of them. We conclude that the stimulation of GABA A receptors, of which the activity is decreased during alcohol withdrawal, significantly improves the disturbances in the sleep–wake states in the alcohol-dependent rats, in a time-related manner, and there are significant pharmacodynamic differences between muscimol and Homotaurine.

  • Effects of alcohol dependence on shock-induced fighting: Action of muscimol and Homotaurine
    Pharmacology biochemistry and behavior, 1992
    Co-Authors: Saïd Rouhani, E. Emmanouilidis, G. Tran, C. Payan, A. Castresana, A. Soulairac, S. Poenaru
    Abstract:

    We have applied the electroshock-induced fighting behavior to the study of experimental alcohol dependence. Adult Wistar rats were intoxicated chronically with ethanol (10 g/kg/24 h) for 13 days. Electroshock-induced fighting behavior was studied during chronic intoxication and withdrawal in comparison with normal rats receiving a water-carbohydrate solution isocaloric to ethanol. Rats were divided into groups receiving respectively muscimol (0.25 mg/kg), a GABAA agonist; Homotaurine (140 mg/kg) a GABA mimetic; and physiological saline (10 ml/kg), intraperitoneally. During chronic intoxication, rats showed an increase in defensive-fighting behavior. Withdrawal accentuated the aggressive behavior and muscimol and Homotaurine inhibited it. These results confirm the relevance of the electroshock-induced defensive fighting behavior test in chronic intoxication with alcohol, but to show the involvement of GABAergic transmission in the behavioral effects of alcohol withdrawal, additional experiments with other GABA mimetics and with GABA antagonists should be considered.