Journal: Molecular Pain

Article Title: Characterisation of Nav1.7 functional expression in rat dorsal root ganglia neurons by using an electrical field stimulation assay

doi: 10.1177/1744806917745179

Figure Lengend Snippet: ProTx-II blocks sodium channel currents in DRG neurons. (a) Whole cell patch-clamp recordings in DRG and hippocampal neurons were performed to investigate the effect of TTX and ProTx-II on sodium currents (elicited by a test voltage step of 25 ms duration from −80 mV holding potential to −20 mV). Representative sodium current traces from DRG and hippocampal neurons are shown before (black line) and after application of 100 nM TTX (top panel, blue trace) and 300 nM ProTx-II (bottom panel, red trace) for a total duration of 5 min. (b) Averaged data for the experiment in (a) showing normalised amplitude of sodium currents in DRG and hippocampal neurons after incubation with ProTx-II (300 nM) and TTX (100 nM); n = 3–6 cells, ***p < 0.001.

Article Snippet: TTX was purchased from Tocris (Bristol, UK) and ProTx-II from PeptaNova (Sandhausen, Germany).

Techniques: Patch Clamp, Incubation

Journal: Biochemical pharmacology

Article Title: Characterisation of Na(v) types endogenously expressed in human SH-SY5Y neuroblastoma cells.

doi: 10.1016/j.bcp.2012.02.022

Figure Lengend Snippet: Fig. 5. ProTxII and TIIIA inhibit endogenously expressed TTX-sensitive Nav in SH-SY5Y cells. Na+ currents were evoked by stepping from 90 mV to 0 mV for 10 ms. ProTxII (30 nM) or TIIIA (1 mM) were initially examined independently of each other, before examining their combined inhibitory effects of INa. (A) An illustration showing the progressive inhibition of INa by superfusion of ProTxII (30 nM), TIIIA (1 mM) and TTX (1 mM) in a single SH-SY5Y cell. (B) Time plot of a single SH-SY5Y cell showing effects of first ProTxII (30 nM), then ProTxII (30 nM) and TIIIA (1 mM) superfusion. TTX (1 mM) was superfused onto the cell at the end of the experiment to inhibit any remaining Nav. Bars indicate the duration of antagonist superfusion. (C) ProTxII (30 nM) and TIIIA (1 mM) both significantly inhibit INa (p < 0.0001). In two cells, combined application of ProTxII and TIIIA produced greater inhibition of INa than either alone. Numbers in brackets above column bars indicate the number of cells examined for each antagonist. (D) Veratridine-induced tail currents of endogenously expressed TTX-sensitive Nav in SH-SY5Y cells can be inhibited by ProTxII and TIIIA. Veratridine-induced tail currents were evoked by repeating 90 mV to 0 mV step depolarisations five times over a 2.5 s period, at 30 s intervals in the presence of veratridine (50 mM). TIIIA (1 mM) or ProTxII (30 nM) both significantly (p < 0.001) inhibited veratridine-induced tail currents. Combined application of ProTxII and TIIIA produced significantly (p < 0.001) greater inhibition of the veratridine-induced tail current than either alone. Numbers in brackets above column bars represent the number of cells per respective experiment.

Article Snippet: Veratridine was obtained from Ascent Scientific (Bristol, UK), tetrodotoxin (TTX) was from Enzo Life Sciences (Farmingdale, NY, USA) and ProTxII and Agatoxin TK were from Peptides International (Lousiville, KY, USA).

Techniques: Inhibition, Produced

Journal: Molecular Brain

Article Title: Block of T-type calcium channels by protoxins I and II

doi: 10.1186/1756-6606-7-36

Figure Lengend Snippet: Summary of biophysical parameters of various T-type calcium channels in the absence or presence of A, 1 μ M ProTx II and B, 1 μ M ProTx I

Article Snippet: Both ProTx I and ProTx II were purchased from Alomone Labs (Jerusalem, Israel) and were dissolved in external recording solution at the stock concentration of 1 mM.

Techniques: Blocking Assay