Changes: Bicuculline

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Bicuculline chemical structure Bicuculline
Bicuculline IUPAC name
CAS number 485-49-4	ATC code [[ATC_code_\|]][1]
PubChem 10237	DrugBank [2]
Chemical formula	{{{chemical_formula}}}
Molecular weight	367.352 g/mol
Bioavailability
Metabolism
Elimination half-life
Excretion
Pregnancy category
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Bicuculline (BIC) is a light-sensitive competitive antagonist of GABA_A receptors. It was originally identified in 1932 in plant alkaloid extracts^[1] and has been isolated from Dicentra cucullaria, Adlumia fungosa, Fumariaceae, and several Corydalis species. Since it blocks the inhibitory action of GABA receptors, the action of bicuculline mimics epilepsy. This property is utilised in laboratories across the world in the in vitro study of epilepsy, generally in hippocampal or cortical neurons in prepared brain slices from rodents. This compound is also routinely used to isolate glutamatergic (excitatory amino acid) receptor function.

The action of bicuculline is primarily on the ionotropic GABA_A receptors, which are ligand-gated ion channels concerned chiefly with the passing of chloride ions across the cell membrane, thus promoting an inhibitory influence on the target neuron. These receptors are the major targets for benzodiazepines and related anxiolytic drugs.

The half-maximal (IC50) effect of bicuculline on GABA_A receptors is 3 μM.

In addition to being a potent GABA_A receptor antagonist, bicuculine can be used to block Ca²⁺-activated potassium channels ^[2].

Sensitivity to bicuculline is defined by IUPHAR as a major criterion in the definition of GABA_A receptors - however in recent years a new class of ionotropic GABA receptor, defined variously as GABA_AOR or GABA_C has been characterised, which is insensitive to both benzodiazepines and bicuculline.

A water soluble form of bicuculline, bicuculline methiodide, is soluble in water to a concentration of 10 mg/mL.

References

↑ Manske, Can. J. Res. 7:265, 1932
↑ Khawaled R, Bruening-Wright A, Adelman JP, Maylie J (1999) Bicuculline block of small-conductance calcium-activated potassium channels. Pflügers Arch 438: 314-321

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[1] Manske, Can. J. Res. 7:265, 1932

[2] Khawaled R, Bruening-Wright A, Adelman JP, Maylie J (1999) Bicuculline block of small-conductance calcium-activated potassium channels. Pflügers Arch 438: 314-321

[1]

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@@ Line 31: / Line 31: @@
 In addition to being a potent GABA<sub>A</sub> receptor antagonist, bicuculine can be used to block Ca<sup>2+</sup>-activated potassium channels <ref>Khawaled R, Bruening-Wright A, Adelman JP, Maylie J (1999) Bicuculline block of small-conductance calcium-activated potassium channels. Pflügers Arch 438: 314-321</ref>.
-Sensitivity to bicuculline is defined by [[IUPHAR]] as a major criterion in the definition of GABA<sub>A</sub> receptors - however in recent years a new class of ionotropic [[GABA]] receptor, defined variously as [[GABA A receptor|GABA<SUB>AOR</SUB>]] or [[GABA A receptor|GABA<SUB>C</SUB>]] has been characterised, which is insensitive to both benzodiazepines and bicuculline.
+Sensitivity to bicuculline is defined by [[IUPHAR]] as a major criterion in the definition of GABA<sub>A</sub> receptors - however in recent years a new class of ionotropic [[GABA receptor]], defined variously as [[GABA A receptor|GABA<SUB>AOR</SUB>]] or [[GABA A receptor|GABA<SUB>C</SUB>]] has been characterised, which is insensitive to both benzodiazepines and bicuculline.
 A water soluble form of bicuculline, bicuculline methiodide, is soluble in water to a concentration of 10 mg/mL.
@@ Line 39: / Line 39: @@
 <references/>
+[[Category:Analeptic drugs]]
 [[Category:GABA antagonists]]