Madeja M, Wolf C, Speckmann EJ. Reduction of voltage-operated sodium currents by the anticonvulsant drug sulthiame.
Brain Res 2001;
900:88-94. [PMID:
11325350 DOI:
10.1016/s0006-8993(01)02262-4]
[Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of the sulfonamide derivative sulthiame (Ospolot) on voltage-operated sodium channels was investigated in acutely isolated neurons from the guinea pig hippocampus using the whole-cell patch-clamp technique. Sulthiame in a concentration of 10 microg/ml reduced the inactivating sodium currents without affecting potassium currents. The effect was not dependent on voltage. At therapeutic concentration of 1 to 10 microg/ml sodium currents were reduced by 13 to 25% of control. Reductions of this size (induced by the specific sodium channel blocker tetrodotoxin or by 10 microg/ml sulthiame itself) impaired repetitive generation of action potentials and reduced the maximum discharge frequency by 20 to 40%. In summary, the anticonvulsant drug sulthiame exerts blocking effects on sodium channels which can be assumed to be anticonvulsant and to be different from the effects induced by blockade of carbonic anhydrase.
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