Figure 1
From: Hydrogen sulfide regulates hippocampal neuron excitability via S-sulfhydration of Kv2.1
NaHS inhibits recombinant Kv2.1. (A) Families of currents evoked in a HEK293 cell stably expressing Kv2.1 before and during exposure to NaHS (200 μM). Currents were evoked by step-depolarizations, applied up to + 80 mV in 10 mV increments from a holding potential of − 70 mV. Scale bars apply to both families of currents. (B) Mean (± s.e.m.) current–density versus voltage relationships obtained in 17 cells before (solid circles) and during (open circles) exposure to NaHS (200 μM). (C) Mean (± s.e.m., each point taken from 5 to 7 cells) concentration–response relationship illustrating the effects of NaHS on Kv2.1. Inhibition was determined using currents evoked by step-depolarizations from − 70 to + 50 mV). (D) Plot of voltage-dependence of activation of Kv2.1 before (solid circles) and during (open circles) exposure to NaHS (200 μM). Data are means ± s.e.m. Curves were obtained by fitting data to the sigmoidal Boltzmann function. (E) Example time-series plot illustrating normalized current amplitudes evoked by step-depolarizations from − 70 to + 50 mV in a Kv2.1-expressing HEK293 cell. For the period indicated by the horizontal bar, NaHS (200 μM) was applied via the perfusate. (F) as (E), except that, following washout of NaHS, the cell was exposed to dithiothreitol (DTT, 1 mM) for the period indicated by the second horizontal bar. Inset shows example currents under the conditions indicated (DTT applied after washout of NaHS). Scale bars: 2 nA (vertical) and 10 ms (horizontal).
