PT  - JOURNAL ARTICLE
AU  - Joseph J. McArdle
AU  - Thomas L. Lentz
AU  - Veit Witzemann
AU  - Holger Schwarz
AU  - Scott A. Weinstein
AU  - James J. Schmidt
TI  - Waglerin-1 Selectively Blocks the Epsilon Form of the Muscle Nicotinic Acetylcholine Receptor
DP  - 1999 Apr 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 543--550
VI  - 289
IP  - 1
4099  - http://jpet.aspetjournals.org/content/289/1/543.short
4100  - http://jpet.aspetjournals.org/content/289/1/543.full
SO  - J Pharmacol Exp Ther1999 Apr 01; 289
AB  - Neonatal mice resist the lethal effect of Waglerin-1. Because Waglerin-1 blocks the nicotinic acetylcholine receptor of mature end-plates, the appearance of lethality may result from the ε- for γ-subunit substitution. In support of this hypothesis, adult knockout (KO) mice lacking the gene coding for the ε-subunit resist the lethal effect of Waglerin-1. In contrast, heterozygous litter mates respond to Waglerin-1 like adult wild-type mice. In vitro application of 1 μM Waglerin-1 inhibited spontaneous miniature end-plate potentials and evoked end-plate potentials of adult wild-type and heterozygous KO mice. Both miniature end-plate potentials and end-plate potentials of neonatal wild-type and adult homozygous KO mice resisted Waglerin-1. Waglerin-1 decreased the end-plate response of adult wild-type mice to iontophoretically applied acetylcholine (ACh) with an IC50value of 50 nM; 1 μM Waglerin-1 decreased the ACh response to 4 ± 1% of control for adult heterozygous KO mice. In contrast, 1 μM Waglerin-1 decreased the ACh response to 73 ± 2% of control for wild-type mice less than 11 days old and had no effect on the ACh response of adult homozygous KO mice. Between 11 and 12 days after birth, the suppressant effect of Waglerin-1 on wild-type end-plate responses to ACh dramatically increased. Waglerin-1 reduced binding of α-bungarotoxin to end-plates of adult but not neonatal wild-type mice. These data demonstrate that Waglerin-1 selectively blocks the mouse muscle nicotinic acetylcholine receptor containing the ε-subunit. The American Society for Pharmacology and Experimental Therapeutics