NOTE: This item is not available outside the Texas A&M University network. Texas A&M affiliated users who are off campus can access the item through NetID and password authentication or by using TAMU VPN. Non-affiliated individuals should request a copy through their local library's interlibrary loan service.
The pharmacokinetics of cuticular penetration of avermectin and decreased uptake resistance in the house fly, Mucsa domestica L.
Abstract
A study was conducted with the house fly, Musca domestics (L.), to examine the pharmacokinetics of cuticular penetration of insecticides and to elucidate the mechanism of decreased uptake resistance to insecticides. The test insecticide was avermectin. Tritiated and nontritiated forms were used. Fly strains used were SBO, a multimutant (stubby wing, brown body, ocra eye) insecticide susceptible strain and Cyro-R, a wild type strain with low level resistance to avermectin associated with decreased insecticide uptake. Insecticide uptake was measured in adult flies exposed briefly to avermectin residues on glass surfaces. Cuticular waxes were not shown to play a critical role in insecticide uptake and quantitative differences in wax were not seen between strains. Interstrain differences were seen in the amount of loss from the cuticular surface onto holding containers following treatment, with the Cyro-R flies exhibiting 4X more. Loss of avermectin from the cuticular surface was rapid, most occurring within 30 min following initial exposure. Specific binding of avermectin to proteins was higher in the susceptible strain, indicating the presence of a finite number of binding sites available for avermectin uptake. More radioactivity was present in the hemolymph of susceptible flies following brief exposure to avermectin. A quantitative change in the number of insecticide transport proteins was hypothesized for the differences seen between strains. To determine a natural function for an insecticide transport mechanism, flies were exposed orally to [14C] radiolabeled glucose. Exposure was followed by measurements of [14C] incorporation into the wax. Exposure to avermectin following exposure to labeled glucose reduced [14C] buildup in the cuticle, providing evidence the same transport mechanism was involved in hydrocarbon efflux and insecticide influx. The cuticular wax does not appear to play a critical role in insecticide uptake. A saturable high affinity avermectin binding protein(s) appears to be responsible for transporting avermectin from the waxes into the hemolymph. Decreased uptake resistance may be associated with a decreased number of these transport proteins. The transport of hydrocarbons to the cuticular surface appears to be a natural function for a protein that facilitates insecticide entry.
Description
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references.
Collections
Citation
Gardiner, Elisabeth Michelle Marie (1994). The pharmacokinetics of cuticular penetration of avermectin and decreased uptake resistance in the house fly, Mucsa domestica L.. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -G221.
Request Open Access
This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.