A Potent Activator of KCa3.1 and KCa2 Channels
Cat #: N-325
  • Lyophilized Powder
  • Bioassay Tested
  • Source Synthetic
    MW: 258.03
    Purity: >98% (HPLC)
    Effective concentration 0.01-5 μM.
    Chemical name 4,5-dichloro-1,3-diethyl-1,3-dihydro-benzoimidazol-2-one.
    Molecular formula C11H12Cl2N2O.
    Activity NS-4591 is a potent SK4 channel activator; 30 nM doubled KCa3.1 currents in HEK cells1.
      • Hougaard, C. et al. (2009) J. Pharmacol. Exp. Ther. 328, 28.

    Shipping and storage Shipped at room temperature. Product as supplied can be stored intact at room temperature for several weeks. For longer periods, it should be stored at -20°C.
    Solubility 100 mM DMSO. Centrifuge all product preparations before use (10000 x g 5 min).
    Storage of solutions Up to four weeks at 4°C or three months at -20°C.
      • Alomone Labs NS-4591 activates KCa3.1 currents expressed in HEK 293T cells.
        A. Time course of KCa3.1 current amplitude and its activation by 1 µM NS-4591 (#N-325). Currents were elicited by application of voltage ramp from -120 mV to +60 mV (150 msec), delivered every 10 seconds, holding potential of -80mV. B. Superimposed example traces of current responses before and during perfusion of 1 µM NS-4591 as indicated.
      • Wei, A.D. et al. (2005) Pharmacol. Rev. 57, 463.
      • Hougaard, C. et al. (2009) J. Pharmacol. Exp. Ther. 328, 28.
      • Calcium activated potassium (KCa) channels include three types of small-conductance channels, KCa2.1, KCa2.2 and KCa2.3, and the intermediate conductance channel KCa3.1. Both small- and intermediate-conductance KCa channels play important roles in many processes involving Ca2+-dependent signaling in both electrically excitable and non-excitable cells1.

        NS-4591 is a potent synthetic activator of KCa3.1 and KCa2 channels. It has an effective concentration of 0.01-5 μM. NS-4591 does not seem to affect KCa1.1 or NaV channels but does cause a small reduction in CaV currents and a prominent reduction in delayed rectifier KV channel. In whole-cell patch-clamp experiments conducted, NS-4591 doubled IK-mediated currents at a concentration of 45±6 nM while 530±100 nM was required for doubling of SK3-mediated currents. The effect of NS-4591 was also examined in acutely dissociated bladder primary afferent neurons and NS-4591 was shown to inhibit the number of action potentials generated by suprathreshold depolarizing pulses. NS-4591 reduces the amplitude of detrusor twitches in a concentration dependent manner. in vivo experiments in rats and cats have demonstrated that 30 mg/kg inhibits bladder hyper activity induced by capsaicin and acetic acid. NS-4591 might prove to be an important agent for the treatment of bladder hyperactivity.

    Target KCa3.1, KCa2 channels
    Last update: 24/06/2019

    NS-4591 (#N-325) is a highly pure, synthetic, and biologically active compound.

    For research purposes only, not for human use