Barann M, Göthert M, Fink K, Bönisch H. Inhibition by anaesthetics of 14C-guanidinium flux through the voltage-gated sodium channel and the cation channel of the 5-HT3 receptor of N1E-115 neuroblastoma cells.
NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1993;
347:125-32. [PMID:
7682657 DOI:
10.1007/bf00169256]
[Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The influence of local and general anaesthetics on cation influx through the fast, voltage-dependent sodium channel and the 5-HT3 receptor cation channel was studied in N1E-115 mouse neuroblastoma cells by measuring 2-min influx of the organic cation 14C-guanidinium induced by either veratridine (1 mmol/l) or 5-HT (100 mumol/l). The veratridine-induced influx of 14C-guanidinium was potentiated by scorpion toxin and inhibited by tetrodotoxin. The 5-HT-induced 14C-guanidinium influx was not affected by tetrodotoxin but it was inhibited by nanomolar concentrations of the selective 5-HT3 receptor antagonists ondansetron and ICS 205-930; at high micromolar concentrations these compounds also inhibited the veratridine-induced influx of 14C-guanidinium. The 14C-guanidinium influx through both channels was inhibited by local and general anaesthetics. The rank order of potency for inhibition of veratridine-induced influx by local anaesthetics was tetracaine > bupivacaine > cocaine > lidocaine > procaine and that for inhibition of the 5-HT3 receptor channel was tetracaine > bupivacaine > cocaine > procaine > lidocaine. With the exception of procaine and cocaine, which were equipotent at both channels, the local anaesthetics were 4.4-fold (lidocaine) to 25-fold (tetracaine) more potent at the fast sodium channel than at the 5-HT3 receptor channel. The rank order of potency for general anaesthetics was propofol > etomidate = alfaxalone = ketamine > thiopental = methohexital at the fast sodium channel, and propofol > or = etomidate > alfaxalone = methohexital > thiopental > ketamine at the 5-HT3 receptor channel.(ABSTRACT TRUNCATED AT 250 WORDS)
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