Abstract
Ptychodiscus brevis toxin T446 markedly enhances persistent activation of voltage-sensitive sodium channels in neuroblastoma cells by veratridine. Half-maximal enhancement is observed at 50 ng of T446 per milliliter. At maximally effective concentrations, T446 has no effect on specific binding of 125I-labeled scorpion toxin and slightly enhances specific binding of [3H]saxitoxin. Thus, T446 enhances veratridine action but does not bind to any of the three neurotoxin receptor sites on the sodium channels that have been previously described. T446 may act at a new toxin-receptor site associated with voltage-sensitive sodium channels.
ACKNOWLEDGMENTS We thank Ms. Cynthia S. Morrow and Ms. Sherryann C. Pesheck for excellent technical assistance.
- Copyright © 1981 by The American Society for Pharmacology and Experimental Therapeutics
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|