Immunological and histopathological responses of the kidney of common carp (Cyprinus carpio L.) sublethally exposed to glyphosate.

Glyphosate is a broad-spectrum herbicide frequently used world widely in agricultural and non-agricultural areas to control unwanted plants. Health risk of chronic and subchronic exposure of glyphosate on animals and humans has received increasing attention in recent years. The aim of this study was to evaluate the effects of glyphosate on the immunoglobulin M (IgM), complement C3 (C3), and lysozyme (LYZ) in the kidney of common carp exposed to 52.08 or 104.15mgL(-1) of glyphosate for 168h. The results showed that the transcriptions of IgM, C3, or LYZ were altered due to glyphosate-exposure, for example, IgM and C3 initially increased at 24h later it decreased (except for a increase of C3 in higher dose group at 24h) while the expression of G-type LYZ were not affected at 24h, then increased at 72h, but decreased at the end of test, however C-type LYZ expression was initially up-regulated (24-72h) but down-regulated at the end of exposure (168h). However, glyphosate-exposure generally decreased the contents of IgM and C3 or inhibited LYZ activity in the kidney of common carp. In addition, glyphosate-exposure also caused remarkable histopathological damage, mainly including vacuolization of the renal parenchyma and intumescence of the renal tubule in fish kidney. The results of this study indicate that glyphosate causes immunotoxicity on common carp via suppressing the expressions of IgM, C3, and LYZ and also via damaging the fish kidney.