evaluation of the expression of p-glycoprotein in propoxur-resistant caco-2 cells.

there is a great concern about the effect of propoxur, as one of the more common n-methyl carbamate pesticides, on human health due to its extensive use in agricultural and non-agricultural applications. caco-2 cells became resistant to propoxur, and the resistance was confirmed through mtt assay. then the cell membrane integrity and p-glycoprotein expression were measured by ldh assay and western blot analysis, respectively and compared to the parent cells.  contrary to what was expected, the expression of p-glycoprotein in propoxur resistant cells was lower than parent cells.this study indicates that the resistance to propoxur may not be related to p-glycoprotein expression directly, since p-glycoprotein expression has decreased in these cells.