Methods for studying renal toxicity.

Most nephrotoxic compounds, such as drugs and industrial compounds, exert their noxious effect in a specific region of the kidney. Within the kidney, the proximal tubular cells (PTC) are exposed to the highest concentrations of xenobiotics due to their transporting, concentrating and drug metabolizing abilities. Therefore mechanisms of nephrotoxicity are best studied in these particular cells. For this purpose, well defined in vitro systems are needed. Many in vitro systems to study renal toxicity have been described, ranging from isolated perfused kidneys, kidney slices, isolated tubules, primary cultures of renal cells, kidney cell lines to isolated organelles, mainly derived from rabbit, rat and mouse; reviews of the various available systems have been published in the past (Gstraunthaler 1988,Boogaard et al. 1990). In the first part of the present paper new developments in the application of kidney slices, isolated proximal tubular cells and cell lines will be reviewed. In the second part new types of renal toxicity studies in individual living or fixed cells using video microscopy, confocal laser scan microscopy and flow cytometry will be described and discussed.