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The inhibitory effect of copper ions on lymphocyte Kv1.3 potassium channels

100%

Teisseyre A., Mozrzymas J. W.

Journal of Physiology and Pharmacology

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2006

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tom 57

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nr 2

We applied the whole-cell patch-clamp technique to study the inhibitory effect of copper ions (Cu) on the activity of Kv1.3 channels expressed in human lymphocytes. Application of Cu reversibly inhibited the currents to about 10% of the control value in a concentration-dependent manner with the half blocking concentration of 5.28±0.5 µM and the Hill's coefficient of 3.83±0.18. The inhibitory effect was saturated at 10 µM concentration. The inhibition was time-dependent and it was correlated in time with a significant slowing of the current activation rate. In contrast the voltage dependence of activation was not changed by Cu as well as the inativation kinetics. The inhibitory effect of Cu was voltage-independent. It was also unaffected by changing the extracellular pH in the range from 6.4 to 8.4, raising the extracellular potassium concentration to 150 mM and by changing the holding potential from -90 to -60 mV. The inhibitiory effect of Cu was not changed in the presence of an equivalent concentration of Zn. Altogether, obtained data suggest that Cu inhibits Kv1.3 channels by a different mechanism than Zn and that Cu and Zn act on different binding sites. The inhibitory effect of Cu was probably due to a specific binding of Cu on binding sites on the channels. Possible physiological significance of the Cu-induced inhibition of Kv1.3 channels is discussed.

2

Effect of econazole and benzydamine on sensory neurons in culture

84%

Mathivanan S., De la Torre Martinez R., Wolf C., Mangano G., Polenzani L., Milanese C., Ferrer-Montiel A.

Journal of Physiology and Pharmacology

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2016

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tom 67

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nr 6

3

The influence of protons and zinc ions on the steady-state inactivation of Kv1.3 potassium channels

84%

Teisseyre A., Mozrzymas J. W.

Cellular and Molecular Biology Letters

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2007

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tom 12

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nr 2

Using the whole-cell patch-clamp technique, we investigated the influence of extracellular pH and zinc ions (Zn2+) on the steady-state inactivation of Kv1.3 channels expressed in human lymphocytes. The obtained data showed that lowering the extracellular pH from 7.35 to 6.8 shifted the inactivation midpoint (Vi) by 17.4 ± 1.12 mV (n = 6) towards positive membrane potentials. This shift was statistically significant (p < 0.05). Applying 100 μM Zn2+ at pH 6.8 further shifted the Vi value by 16.55 ± 1.80 mV (n = 6) towards positive membrane potentials. This shift was also statistically significant (p < 0.05). The total shift of the Vi by protons and Zn2+ was 33.95 ± 1.90 mV (n = 6), which was significantly higher (p < 0.05) than the shift caused by Zn2+ alone. The Zn2+-induced shift of the Vi at pH 6.8 was almost identical to the shift at pH = 7.35. Thus, the proton-and Zn2+-induced shifts of the Vi value were additive. The steady-state inactivation curves as a function of membrane voltage were compared with the functions of the steady-state activation. The total shift of the steady-state inactivation was almost identical to the total shift of the steady-state activation (32.01 ± 2.10 mV, n = 10). As a result, the “windows” of membrane potentials in which the channels can be active under physiological conditions were also markedly shifted towards positive membrane potentials. The values of membrane voltage and the normalised chord conductance corresponding to the points of intersection of the curves of steady-state activation and inactivation were also calculated. The possible physiological significance of the observed modulatory effects is discussed herein.

4

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In vitro effects of fipronil on neuronal excitability in mammalian and molluscan nervous systems

67%

Varro P., Gyori J., Vilagi I.

Annals of Agricultural and Environmental Medicine

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2009

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tom 16

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nr 1

71-77

Ograniczanie wyników

2 Journal of Physiology and Pharmacology

1 Annals of Agricultural and Environmental Medicine

1 Cellular and Molecular Biology Letters

2 Mozrzymas J. W.

2 Teisseyre A.

1 De la Torre Martinez R.

1 Ferrer-Montiel A.

1 Gyori J.

1 Mangano G.

1 Mathivanan S.

1 Milanese C.

1 Polenzani L.

1 Varro P.

1 Vilagi I.

1 Wolf C.

1 2016

1 2009

1 2007

1 2006

The inhibitory effect of copper ions on lymphocyte Kv1.3 potassium channels

Effect of econazole and benzydamine on sensory neurons in culture

The influence of protons and zinc ions on the steady-state inactivation of Kv1.3 potassium channels

In vitro effects of fipronil on neuronal excitability in mammalian and molluscan nervous systems