Accumulation of ochratoxin A in rat kidney in vivo and in cultivated renal epithelial cells in vitro.

In this study we determined the distribution of ochratoxin A (OTA) in renal tissue as well as its content and binding pattern in different cell types stemming from the proximal tubule (OK cells) and collecting duct (MDCK cells) of the kidney. To obtain the net amount of OTA in renal tissue, the relative amount in the vascular compartment was calculated and subtracted. After acute administration of OTA to male Wistar rats, the highest concentrations were detected in the papilla and inner medulla. Concentrations in the outer medulla and in the cortical tissue were 50% lower. Sub-chronic (6 day) exposure to OTA resulted in a similar distribution in young rats (6 weeks old) but in a different distribution in adult rats (2 year old). Cultured MDCK-C11 cells (representing intercalated cells) showed a higher OTA content after 48 h of exposure to 1 mumol/1 OTA than another MDCK cell subtype (MDCK-C7, representing principal cells) and OK cells. Additionally, the capability of cell extracts to bind OTA was the highest in MDCK-C11 cells followed by cell extracts of OK cells and cell extracts of MDCK-C7 cells. In two cell types studied, OK and MDCK-C11 cells, OTA was bound preferentially by organellar components and less by cytosolic ones.