Veratridine in low concentrations (20 μM) and at high pH (pH 9) acts as a synergist for carbamylcholine-induced depolarizations in the electroplax of electric eel. This potentiation is not sensitive to tetrodotoxin, but is significantly reduced by d-tubocurarine. Veratridine alone does not depolarize this preparation at the concentration used (20 μM). The increased carbamylcholine depolarization arising in the presence of veratridine does not simply sum with the carbamylcholine depolarization; the fractional contribution of veratridine to the total depolarization decreases as the carbamylcholine concentration is increased, and at 50 μM carbamylcholine no significant difference is apparent between groups with and without veratridine. Depolarization with increased external K+, unlike carbamylcholine depolarization, is not potentiated by veratridine.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)