Deltamethrin Inhibits the Human T-type Voltage-Sensitive Calcium Channel (Cav3.2)

Abstract: The goal of this study was to determine the effect of deltamethrin, a pyrethroid insecticide, on CaV3.2, a human T-type voltage-sensitive calcium channel expressed in Xenopus laevis (X. laevis) oocytes. CaV3.2 cDNA was transcribed into cRNA; the cRNA was then injected into X. laevis oocytes and electrophysiologically characterized using the two-electrode voltage lamp technique with Ba2+ as a charge carrier. Deltamethrin (10-7 M) reduced peak current in a nonreversible manner compared to the untreated control, but had no effect on the voltage dependent activation and inactivation kinetics. These findings confirm that human CaV3.2 is a target for deltamethrin and quite possibly other pyrethroid insecticides. These studies provide insight into the molecular mechanisms of the effect that pyrethroids have on voltage-sensitive calcium channels in general. This information will allow a more complete understanding of the molecular and cellular nature of pyrethroid-induced toxicity and expand our knowledge of the structure-activity relationships of pyrethroids with regard to their action on voltage-sensitive calcium channels.

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