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Thies Peters - One of the best experts on this subject based on the ideXlab platform.

  • relaxation of evoked contractile activity of isolated guinea pig ileum by kavain
    Planta Medica, 1997
    Co-Authors: Ulrike Seitz, Johannes Gleitz, Angela Ameri, Helmut Pelzer, Thies Peters
    Abstract:

    : Kava Pyrones are the pharmacologically active compounds of Piper methysticum Forst. In the present study, the effect of the synthetic kava pyrone (+/-)-kavain was investigated on evoked contractile activity of isolated guinea-pig ileum. (+/-)-Kavain (1 microM-1 mM) dose-dependently reduced contractions of ileum evoked by carbachol (10 microM), by BAY K 8644 (0.3 microM), or by substance P (0.05 microM). (+/-)-Kavain also inhibited the contractile responses induced by raising the extracellular K+ concentration from 4 to 20 mM and by blocking the K+ channel by barium chloride (1 mM) or 4-aminopyridine (0.3 mM). After pre-incubation with 1 microM nifedipine, carbachol (1 microM) evoked 18.2 +/- 14.3% of contraction at control (i.e. prior pre-incubation with nifedipine). This remaining response was completely abolished by high concentrations of (+/-)-kavain (400 microM). After treatment of the longitudinal ileum strips with pertussis toxin (PTX), carbachol (1 microM) evoked 27.0 +/- 6.2% of the control response in untreated ileum. These contractions were also blocked by (+/-)-kavain (400 microM). However, (+/-)-kavain had no effect on the caffeine-induced (20 mM) contractions of ileum strips, which were permeabilized with digitonin or beta-escin. Moreover, it failed to affect Ca(2+)-evoked contractions of skinned muscles. These results suggest that the kava pyrone (+/-)-kavain may act in a non-specific musculotropic way on the smooth muscle membrane.

  • Relaxation of evoked contractile activity of isolated guinea-pig ileum by (±)-kavain
    Planta Medica, 1997
    Co-Authors: Ulrike Seitz, Johannes Gleitz, Angela Ameri, Helmut Pelzer, Thies Peters
    Abstract:

    : Kava Pyrones are the pharmacologically active compounds of Piper methysticum Forst. In the present study, the effect of the synthetic kava pyrone (+/-)-kavain was investigated on evoked contractile activity of isolated guinea-pig ileum. (+/-)-Kavain (1 microM-1 mM) dose-dependently reduced contractions of ileum evoked by carbachol (10 microM), by BAY K 8644 (0.3 microM), or by substance P (0.05 microM). (+/-)-Kavain also inhibited the contractile responses induced by raising the extracellular K+ concentration from 4 to 20 mM and by blocking the K+ channel by barium chloride (1 mM) or 4-aminopyridine (0.3 mM). After pre-incubation with 1 microM nifedipine, carbachol (1 microM) evoked 18.2 +/- 14.3% of contraction at control (i.e. prior pre-incubation with nifedipine). This remaining response was completely abolished by high concentrations of (+/-)-kavain (400 microM). After treatment of the longitudinal ileum strips with pertussis toxin (PTX), carbachol (1 microM) evoked 27.0 +/- 6.2% of the control response in untreated ileum. These contractions were also blocked by (+/-)-kavain (400 microM). However, (+/-)-kavain had no effect on the caffeine-induced (20 mM) contractions of ileum strips, which were permeabilized with digitonin or beta-escin. Moreover, it failed to affect Ca(2+)-evoked contractions of skinned muscles. These results suggest that the kava pyrone (+/-)-kavain may act in a non-specific musculotropic way on the smooth muscle membrane.

  • kavain inhibits non stereospecifically veratridine activated na channels
    Planta Medica, 1996
    Co-Authors: Johannes Gleitz, Angela Ameri, Norbert Gottner, Thies Peters
    Abstract:

    : The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (+/-)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (+/- S.D.) of 71 +/- 22, 72 +/- 7, 120 +/- 37 micromol/l (+)-kavain and 77 +/- 21, 90 +/- 14, 92 +/- 23 micromol/l (+/-)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava Pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.

  • Kavain inhibits non-stereospecifically veratridine-activated Na+ channels.
    Planta Medica, 1996
    Co-Authors: Johannes Gleitz, Angela Ameri, Norbert Gottner, Thies Peters
    Abstract:

    : The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (+/-)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (+/- S.D.) of 71 +/- 22, 72 +/- 7, 120 +/- 37 micromol/l (+)-kavain and 77 +/- 21, 90 +/- 14, 92 +/- 23 micromol/l (+/-)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava Pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.

  • kavain inhibits veratridine activated voltage dependent na channels in synaptosomes prepared from rat cerebral cortex
    Neuropharmacology, 1995
    Co-Authors: Johannes Gleitz, A. Beile, Thies Peters
    Abstract:

    Abstract Kava Pyrones are pharmacologically active compounds extracted from Piper methysticum Forst. Because kava Pyrones were characterized by their anticonvulsive, analgesic and centrally muscle relaxing action, we investigated the influence of (±)-kavain, a synthetic kava pyrone, on veratridine-stimulated increase in intrasynaptosomal Na + concentration ([Na + ] i ) of rat cerebrocortical synaptosomes. [Na + ] i was measured spectrofluorometrically employing SBFI as Na + sensitive fluorescence dye. Veratridine (5 μmol/l) enhanced basal [Na + ] i 6.6-fold from 11.3 to 74.1mmol/l Na + . Incubation of synaptosomes for 100 sec with (±)-kavain was sufficient to reduce dose dependently the stimulated increase of [Na + ] i with an IC 50 value of 86.0 μmol/l, and almost complete inhibition of Na + -channels was attained with 400 μmol/l (±)-kavain. The reference compounds, procain (400 μmol/l) and tetrodotoxin (TTX, 10 μmol/l) reduced veratridine-elevated [Na + ] i to 30.4% and 7.9% of control whereas the centrally acting muscle relaxant mephenesin (400 μmol/l) was without any effect. Postapplication of 400 μmol/l (±)-kavain or 10 μmol/l TTX immediately diminished veratridine-elevated [Na + ] i to nearly basal levels with a half life time of 69.7 and 41.8 sec, respectively. To study the influence of (±)-kavain on non stimulated synaptosomes, an increase in [Na + ] i was induced by 200 μmol/l ouabain, which enhanced [Na + ] i hyperbolically with an initial rate of 18.4 mmol Na + /l min. Preincubation of synaptosomes with 400 μmol/l (±)-kavain or 10 μmol/l TTX partly prevented Na + -influx for both compounds to the same extent of about 57% of control. The presented data indicate a fast and specific inhibition of voltage-dependent Na + -channels by (±)-kavain.

Jorg Walden - One of the best experts on this subject based on the ideXlab platform.

  • Effects of (+/-)-kavain on voltage-activated inward currents of dorsal root ganglion cells from neonatal rats.
    European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (+/-)-kavain, on voltage-dependent ion channel currents was studied. Effects of (+/-)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca2+ and Na+ currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (+/-)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca2+ and Na+ channel currents within 3-5 min. As the solubility of (+/-)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (+/-)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca2+ and Na+ currents, which partly recovered within 2-5 min even in the presence of the drug. The present study indicates that (+/-)-kavain reduces currents through voltage-activated Na+ and Ca2+ channels.

  • effects of kavain on voltage activated inward currents of dorsal root ganglion cells from neonatal rats
    European Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Abstract Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (±)-kavain, on voltage-dependent ion channel currents was studied. Effects of (±)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca 2+ and Na + currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (±)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca 2+ and Na + channel currents within 3–5 min. As the solubility of (±)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (±)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca 2+ and Na + currents, which partly recovered within 2–5 min even in the presence of the drug. The present study indicates that (±)-kavain reduces currents through voltage-activated Na + and Ca 2+ channels.

  • the influence of kavain on population spikes and long term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

  • The influence of (±)-kavain on population spikes and long-term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

Johannes Gleitz - One of the best experts on this subject based on the ideXlab platform.

  • [3H]-monoamine uptake inhibition properties of kava Pyrones.
    Planta Medica, 1997
    Co-Authors: Ulrike Seitz, Almut Schüle, Johannes Gleitz
    Abstract:

    : Three kava Pyrones, the natural compounds (+)-methysticine and (+)-kavain, and the synthetic racemate (+/-)-kavain, were tested concerning their action on in vitro uptake of monoamines in synaptosomes prepared from the cerebral cortex and hippocampus of rats. (+/-)-Kavain and (+)-kavain were found to potently inhibit the uptake of [3H]-noradrenaline. Uptake of [3H]-noradrenaline was inhibited in the following order of potency: (+/-)-kavain = (+)-kavain > (+)-methysticine, whereas none of the kava Pyrones efficiently blocked the uptake of [3H]-serotonin. The results indicate a pyrone-specific non-stereo-selective inhibition of the [3H]-noradrenaline uptake which might be responsible for or, at least, contribute to the psychotropic properties of kava Pyrones.

  • relaxation of evoked contractile activity of isolated guinea pig ileum by kavain
    Planta Medica, 1997
    Co-Authors: Ulrike Seitz, Johannes Gleitz, Angela Ameri, Helmut Pelzer, Thies Peters
    Abstract:

    : Kava Pyrones are the pharmacologically active compounds of Piper methysticum Forst. In the present study, the effect of the synthetic kava pyrone (+/-)-kavain was investigated on evoked contractile activity of isolated guinea-pig ileum. (+/-)-Kavain (1 microM-1 mM) dose-dependently reduced contractions of ileum evoked by carbachol (10 microM), by BAY K 8644 (0.3 microM), or by substance P (0.05 microM). (+/-)-Kavain also inhibited the contractile responses induced by raising the extracellular K+ concentration from 4 to 20 mM and by blocking the K+ channel by barium chloride (1 mM) or 4-aminopyridine (0.3 mM). After pre-incubation with 1 microM nifedipine, carbachol (1 microM) evoked 18.2 +/- 14.3% of contraction at control (i.e. prior pre-incubation with nifedipine). This remaining response was completely abolished by high concentrations of (+/-)-kavain (400 microM). After treatment of the longitudinal ileum strips with pertussis toxin (PTX), carbachol (1 microM) evoked 27.0 +/- 6.2% of the control response in untreated ileum. These contractions were also blocked by (+/-)-kavain (400 microM). However, (+/-)-kavain had no effect on the caffeine-induced (20 mM) contractions of ileum strips, which were permeabilized with digitonin or beta-escin. Moreover, it failed to affect Ca(2+)-evoked contractions of skinned muscles. These results suggest that the kava pyrone (+/-)-kavain may act in a non-specific musculotropic way on the smooth muscle membrane.

  • Relaxation of evoked contractile activity of isolated guinea-pig ileum by (±)-kavain
    Planta Medica, 1997
    Co-Authors: Ulrike Seitz, Johannes Gleitz, Angela Ameri, Helmut Pelzer, Thies Peters
    Abstract:

    : Kava Pyrones are the pharmacologically active compounds of Piper methysticum Forst. In the present study, the effect of the synthetic kava pyrone (+/-)-kavain was investigated on evoked contractile activity of isolated guinea-pig ileum. (+/-)-Kavain (1 microM-1 mM) dose-dependently reduced contractions of ileum evoked by carbachol (10 microM), by BAY K 8644 (0.3 microM), or by substance P (0.05 microM). (+/-)-Kavain also inhibited the contractile responses induced by raising the extracellular K+ concentration from 4 to 20 mM and by blocking the K+ channel by barium chloride (1 mM) or 4-aminopyridine (0.3 mM). After pre-incubation with 1 microM nifedipine, carbachol (1 microM) evoked 18.2 +/- 14.3% of contraction at control (i.e. prior pre-incubation with nifedipine). This remaining response was completely abolished by high concentrations of (+/-)-kavain (400 microM). After treatment of the longitudinal ileum strips with pertussis toxin (PTX), carbachol (1 microM) evoked 27.0 +/- 6.2% of the control response in untreated ileum. These contractions were also blocked by (+/-)-kavain (400 microM). However, (+/-)-kavain had no effect on the caffeine-induced (20 mM) contractions of ileum strips, which were permeabilized with digitonin or beta-escin. Moreover, it failed to affect Ca(2+)-evoked contractions of skinned muscles. These results suggest that the kava pyrone (+/-)-kavain may act in a non-specific musculotropic way on the smooth muscle membrane.

  • kavain inhibits non stereospecifically veratridine activated na channels
    Planta Medica, 1996
    Co-Authors: Johannes Gleitz, Angela Ameri, Norbert Gottner, Thies Peters
    Abstract:

    : The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (+/-)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (+/- S.D.) of 71 +/- 22, 72 +/- 7, 120 +/- 37 micromol/l (+)-kavain and 77 +/- 21, 90 +/- 14, 92 +/- 23 micromol/l (+/-)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava Pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.

  • Kavain inhibits non-stereospecifically veratridine-activated Na+ channels.
    Planta Medica, 1996
    Co-Authors: Johannes Gleitz, Angela Ameri, Norbert Gottner, Thies Peters
    Abstract:

    : The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (+/-)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (+/- S.D.) of 71 +/- 22, 72 +/- 7, 120 +/- 37 micromol/l (+)-kavain and 77 +/- 21, 90 +/- 14, 92 +/- 23 micromol/l (+/-)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava Pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.

Jens M. Langosch - One of the best experts on this subject based on the ideXlab platform.

  • Effects of (+/-)-kavain on voltage-activated inward currents of dorsal root ganglion cells from neonatal rats.
    European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (+/-)-kavain, on voltage-dependent ion channel currents was studied. Effects of (+/-)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca2+ and Na+ currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (+/-)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca2+ and Na+ channel currents within 3-5 min. As the solubility of (+/-)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (+/-)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca2+ and Na+ currents, which partly recovered within 2-5 min even in the presence of the drug. The present study indicates that (+/-)-kavain reduces currents through voltage-activated Na+ and Ca2+ channels.

  • effects of kavain on voltage activated inward currents of dorsal root ganglion cells from neonatal rats
    European Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Abstract Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (±)-kavain, on voltage-dependent ion channel currents was studied. Effects of (±)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca 2+ and Na + currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (±)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca 2+ and Na + channel currents within 3–5 min. As the solubility of (±)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (±)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca 2+ and Na + currents, which partly recovered within 2–5 min even in the presence of the drug. The present study indicates that (±)-kavain reduces currents through voltage-activated Na + and Ca 2+ channels.

  • the influence of kavain on population spikes and long term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

  • The influence of (±)-kavain on population spikes and long-term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

K. Schirrmacher - One of the best experts on this subject based on the ideXlab platform.

  • Effects of (+/-)-kavain on voltage-activated inward currents of dorsal root ganglion cells from neonatal rats.
    European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (+/-)-kavain, on voltage-dependent ion channel currents was studied. Effects of (+/-)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca2+ and Na+ currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (+/-)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca2+ and Na+ channel currents within 3-5 min. As the solubility of (+/-)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (+/-)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca2+ and Na+ currents, which partly recovered within 2-5 min even in the presence of the drug. The present study indicates that (+/-)-kavain reduces currents through voltage-activated Na+ and Ca2+ channels.

  • effects of kavain on voltage activated inward currents of dorsal root ganglion cells from neonatal rats
    European Neuropsychopharmacology, 1999
    Co-Authors: K. Schirrmacher, Jorg Walden, Jens M. Langosch, U Winter, Dietrich Büsselberg, Dieter Bingmann
    Abstract:

    Abstract Kava Pyrones extracted from pepper Piper methysticum are pharmacologically active compounds. Since kava Pyrones exhibit anticonvulsive, analgesic and centrally muscle relaxing properties, the influence of a synthetic kava pyrone, (±)-kavain, on voltage-dependent ion channel currents was studied. Effects of (±)-kavain on voltage-activated inward currents were analysed in cultured dorsal root ganglion cells derived from neonatal rats. Voltage-activated Ca 2+ and Na + currents were elicited in the whole-cell configuration of the patch clamp technique. Extracellularly applied (±)-kavain dissolved in hydrous salt solutions reduced voltage-activated Ca 2+ and Na + channel currents within 3–5 min. As the solubility of (±)-kavain in hydrous solutions is low, dimethyl sulfoxide (DMSO) was added to the saline as a solvent for the drug in most experiments. When (±)-kavain was dissolved in DMSO, the drug induced a fast and pronounced reduction of both Ca 2+ and Na + currents, which partly recovered within 2–5 min even in the presence of the drug. The present study indicates that (±)-kavain reduces currents through voltage-activated Na + and Ca 2+ channels.

  • the influence of kavain on population spikes and long term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

  • The influence of (±)-kavain on population spikes and long-term potentiation in guinea pig hippocampal slices
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 1998
    Co-Authors: Jens M. Langosch, K. Schirrmacher, Claus Normann, M Berger, Jorg Walden
    Abstract:

    Abstract Little is known about the mechanisms of action of kava Pyrones which are the pharmacological active compounds of the plant Piper methysticum Forst. We investigated the effects of the synthetic kava pyrone (±)-kavain on long-term potentiation (LTP) in the CA1-region of guinea pig hippocampal slices. (±)-Kavain reduced the amplitudes of extracellular field potential changes evoked by electrical stimulation in a concentration dependent manner. These effects were reversible. In experiments with LTP no changes were found in the presence of (±)-kavain. In conclusion, our findings suggest (±)-kavain to be an effective drug in modulating excitatory signals in the hippocampus of guinea pigs. Additionally, no alterations on synaptic plasticity in hippocampal neurons for this kava pyrone can be presumed.

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