The effect of deltamethrin was studied on the Na channels of identified snail neurones under voltage-clamp conditions. At 5 × 10-5 M deltamethrin decreased the resting membrane potential as well as the amplitude of action potentials and increased the negative afterpotentials. The main effect was the slowing down of the inactivation of the Na currents as well as the increase of tail current amplitude. The inactivation curve shifted right along the voltage axis by 10-15 mV. The inactivating phase of Na current could be fitted by two exponentials in the presence of deltamethrin. It was concluded that deltamethrin modified a fraction of sodium channels in the snail neuronal membrane. A kinetic model is proposed for the deltamethrin action in which the presence of two open states, a normal and a modified one, are hypothesized.
ASJC Scopus subject areas
- Agronomy and Crop Science
- Health, Toxicology and Mutagenesis