ORIGINAL ABSTRACT

Glyphosate is a nonselective and postemergent herbicide used to combat weeds in several crops, which raises concerns about risks to human health since residues are detected in urine, human milk, surface water and several types of food. Feces and urine are the major routes of elimination of glyphosate, making the kidney a sensitive target for the development of toxicity. In fact, farmers are at high risk of developing chronic kidney disease. In this sense, this study aims to investigate kidney function by measuring the serum levels of urea and creatinine, examining the histological morphology, and analyzing the mRNA expression of genes related to tubular transport of ions, urea and urates and the biomarker of kidney disease Kim1, and the levels of lead in the kidney in male Wistar rats orally exposed to low levels of glyphosate-based herbicide (GBH: 0, 0.5 or 5 mg/kg) from weaning to adult life by gavage. GBH0.5 showed reduced serum urea concentration, presence of tubulointerstitial swelling and mononuclear cell infiltration into the interstitium, increased gene expression of Kim1 and reduced gene expression of Slc14a1. GBH5 showed reduced serum urea and increased serum creatinine concentrations, tubulointerstitial swelling, interstitial fibrosis, and reduced expression of Trpm6 and Trpv5. Exposure to GBH did not affect the levels of Pb in the kidneys of animals. In conclusion, glyphosate at low doses may cause mild kidney damage. It is necessary to evaluate whether the long-term effects of this constant injury may contribute to the development of chronic kidney disease of uncertain etiology.