Evidence for p-glycoprotein modification of insecticide toxicity in mosquitoes of the Culex pipiens complex
Article first published online: 6 JUN 2002
Medical and Veterinary Entomology
Volume 16, Issue 2, pages 218–222, June 2002
How to Cite
Buss, D. S., Mccaffery, A. R. and Callaghan, A. (2002), Evidence for p-glycoprotein modification of insecticide toxicity in mosquitoes of the Culex pipiens complex. Medical and Veterinary Entomology, 16: 218–222. doi: 10.1046/j.1365-2915.2002.00365.x
- Issue published online: 6 JUN 2002
- Article first published online: 6 JUN 2002
- Culex pipiens;
- Cx. quinquefasciatus;
- calcium channel blocker;
- cell culture;
- vector control;
Abstract Pesticide resistance has parallels with multi-drug resistance syndrome of tumours in clinical medicine, which has been linked to an ATP-dependent pump, p-glycoprotein (P-gp). P-gps pump drugs out of the cell, thereby reducing cellular concentrations of the chemical. P-gps have been found in several invertebrate species and have been shown to provide a defence against environmental xenobiotics, including pesticides.
This study used a model cell culture system to investigate the interaction of pesticides with P-gp. Ivermectin and endosulfan were shown to be strong inhibitors of dye transport out of cells, which is a standard measure of P-gp modulation. We then investigated the action of a P-gp inhibitor, verapamil (calcium channel blocker), on insecticide toxicity to fourth-instar mosquito larvae of the Culex pipiens L. complex (Diptera: Culicidae). Verapamil increased toxicity to examples of three insecticide classes (cypermethrin, endosulfan, ivermectin), but not to chlorpyrifos (organophosphate).
The discovery of a novel protective mechanism in mosquitoes, with a wide substrate range, has implications for the control of important pest and vector species.