The kidneys play a major role in maintaining body homeostasis: they clear the blood from metabolic waste and toxic substances which are ingested with food or as drugs; they regulate salt and water homeostasis and thereby blood pressure; they stimulate blood formation. Each day approximately 180 litres of water are filtered in our kidneys. Together with this water approximately 1.5 kg NaCl and 150 g sugar are filtered. Normaly 99 % of these large amounts are reabsorbed by the renal tubules. This enormous transport work of the kidneys is necessary to avoid dehydration of our body or prevent loss of valuable electrolytes and substrates. Important substances such as NaCl, glucose, or amino acids reenter the systemic blood circulation, as well as most of the filtered water. Substances which need to be removed from the body will be concentrated in the urine. For these reabsorptive and secretory processes special transport proteins, so called transporters, pumps and channels, in the cell membranes of highly specialized tubular cells are responsible. These transport processes are  regulated by complex hormonal systems and are adjusted to the respective needs of the body. Disturbances in these processes, which may be determined genetically or acquired, lead to severe consequences for the whole organism up to life threatening situations, which necessitate dialysis or kidney transplantation.

In the Experimental Nephrology we study meanwhile since more than 15 years function and regulation of some of these transport proteins (e.g. ion channels, water channels, organic cation transporters) under normal and pathologic conditions (e.g. under rejection after kidney transplantation) or their involvment in nephrotoxic effects of drugs. For these studies various experimental models and human tissue are used, which are studied applying modern methods of cellular and molecular biology, electrophysiology, fluorescence microscopy, and molecular imaging.