Catalog Number: 1652
Biological Activity
Prototypical potent and highly selective inhibitor of the small-conductance Ca2+-activated K+-channel (KCa2, SK). Blocks medium after-hyperpolarization in vitro and is brain penetrant and convulsive in vivo.
Technical Data
  • M.Wt:
  • Formula:
  • Sequence:

    (Modifications: Disulfide bridge between 1 - 11, 3 - 15, His-18 = C-terminal amide)

  • Solubility:
    Soluble to 1 mg/ml in water
  • Storage:
    Desiccate at -20°C
  • CAS No:
The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis. All Tocris products are intended for laboratory research use only.
Background References
  1. Apamin.
    Pharmacol.Ther., 1984;25:255
  2. Matching molecules to function: neuronal Ca2+-activated K+ channels and afterhyperpolarizations.
    Stocker et al.
    Toxicon, 2004;43:933
  3. Potassium channel toxins.
    Pharmacol.Ther., 1990;46:137
  4. Behavioral effects of apamin, a selective inhibitor of the SKCa-channel, in mice and rats.
    van der Staay et al.
    Neurosci.Biobehav.Rev., 1999;23:1087

The citations listed below are publications that use Tocris products. Selected citations for Apamin include:

Showing Results 1 - 10 of 17

  1. Cell type-specific transcriptomics of hypothalamic energy-sensing neuron responses to weight-loss.
    Authors: Henry Et al.
    Mol Pain
  2. Increased Basolateral Amygdala Pyramidal Cell Excitability May Contribute to the Anxiogenic Phenotype Induced by Chronic Early-Life Stress.
    Authors: Rau Et al.
    Heart Rhythm
  3. Re-Emergent Inhibition of Cochlear Inner Hair Cells in a Mouse Model of Hearing Loss.
    Authors: Zachary and Fuchs
    J Neurosci
  4. The role of K+ conductances in regulating membrane excitability in human gastric corpus smooth muscle.
    Authors: Lee Et al.
  5. Small-conductance calcium-activated potassium (SK) channels in the amygdala mediate pain-inhibiting effects of clinically available riluzole in a rat model of arthritis pain.
    Authors: Thompson Et al.
    J Neurosci
  6. Apamin does not inhibit human cardiac Na+ current, L-type Ca2+ current or other major K+ currents.
    Authors: Yu Et al.
    J Neurosci
  7. Amiodarone inhibits apamin-sensitive potassium currents.
    Authors: Turker Et al.
    PLoS One
  8. Synaptic NMDA receptor-dependent Ca2+ entry drives membrane potential and Ca2+ oscillations in spinal ventral horn neurons.
    Authors: Alpert and Alford
    PLoS One
  9. Proarrhythmic effect of blocking the small conductance calcium activated potassium channel in isolated canine left atrium.
    Authors: Hsueh Et al.
  10. Asynchronous Ca2+ current conducted by voltage-gated Ca2+ (CaV)-2.1 and CaV2.2 channels and its implications for asynchronous neurotransmitter release.
    Authors: Few Et al.
    Proc Natl Acad Sci U S A
  11. Dynamic interplay of excitatory and inhibitory coupling modes of neuronal L-type calcium channels.
    Authors: Geier Et al.
    Am J Physiol Cell Physiol
  12. Relaxin causes selective outward remodeling of brain parenchymal arterioles via activation of peroxisome proliferator-activated receptor-γ.
    Authors: Chan and Cipolla
    Sci Rep
  13. Postnatal expression of an apamin-sensitive k(ca) current in vestibular calyx terminals.
    Authors: Meredith Et al.
    J Membr Biol
  14. Norepinephrine causes a biphasic change in mammalian pinealocye membrane potential: role of alpha1B-adrenoreceptors, phospholipase C, and Ca2+.
    Authors: Zemkova Et al.
  15. Visinin-like neuronal calcium sensor proteins regulate the slow calcium-activated afterhyperpolarizing current in the rat cerebral cortex.
    Authors: Villalobos and Andrade
    Am J Physiol Gastrointest Liver Physiol
  16. Allosteric block of KCa2 channels by apamin.
    Authors: Lamy Et al.
    J Neurosci
  17. Dopaminergic modulation of spinal neuronal excitability.
    Authors: Han Et al.
    J Biol Chem
Expand to show all
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