Araştırma Makalesi Piretroid İnsektisitlerin Kurbağa İskelet Kası Potasyum Kanalları Üzerine Etkisi

Abstract Influence of Pyrethroid Insecticides on the Potassium Channels of Frog Skeletal Muscle Aim: Pyrethroid insecticides are widely used to control the pests in agricultural areas and influence both target and non-target organisms. The aim of this study is to investigate the effects of two pyrethroid insecticides (permethrin, cypermethrin), that are widely used for the agricultural areas in Mersin, on potassium channel of frog skeletal muscle. Method: The sartorius muscle of Rana ridibunda frogs were used in the study. Groups were composed at three different concentrations (10-5 M, 10-4 M, 10-3 M) for both permethrin and cypermethrin (n=8). Membrane potentials were recorded intracellularly and action potentials were recorded extracellularly. The recordings of action potentials were analyzed with respect to duration, repolarization times and hyperpolarization amplitudes. Time dependent profile of data was investigated at predetermined time intervals (i.e. 0th (control), 15th, 30th 45th and 60th minutes) of recording. Results: Statistical analyses have shown that both two insecticides had no effect on the duration and repolarization time of action potential depending on the dose and time. But hyperpolarization amplitudes shifted towards to negative values within the first 15th minutes and then, continued through the next 45th minutes (pl0.05). Both insecticides had significant time-dependent effect on membrane potentials only in the group treated at the concentration level of 10-3 M whereas their influence was dose-dependent at the 15th, 30th, 45th and 60th minutes (pl0.05). Conclusion: Based on data interpretation, it can be concluded that both pyretroid derivative insecticides used in this study alters cellular electrophysiological parameters by influencing potassium channels with both dose and time dependent manner. No difference was found between permethrin and cypermethrin with this respect.