Polycyclic aromatic hydrocarbons (PAHs)/aryl hydrocarbon receptor (AhR) regulate the expression of target genes, including drug transporter genes which harbor xenobiotic response element (XRE) in their promoter regions. Thus, PAHs/AhR could alter the toxicokinetic profile of many nephrotoxic drugs, including aminoglycosides. In the current study, we investigated the expression and localization of AhR and megalin in rat kidney. Furthermore, we investigated whether AhR and its ligands could modulate the expression of megalin and consequently the gentamicin-induced nephrotoxicity (GN) in rats. Both megalin and AhR receptors are expressed in the proximal tubules of the rat kidney. Treatment with AhR agonist benzo(a)pyrene aggravated GN as indicated by a significant increase in serum creatinine, BUN, KIM1, NAGL, CD-86, and urinary albumin/creatinine ratio. On the other hand, treatment with AhR antagonist resveratrol ameliorated GN as manifested by a pronounced decrease in the aforementioned parameters. The effects of AhR ligands on GN were associated with altered expression of megalin receptor.
Keywords: AhR; Benzo(a)pyrene; Gentamicin; Megalin; Nephrotoxicity; PAHS; Resveratrol.