Prof. J. Loffing

The kidney and the control of ion homeostasis

Regulation of ion transport in the kidney is crucial for maintenance of extracellular electrolyte and fluid homeostasis. The fine-tuning of renal ion excretion takes place in the distal nephron, in which the ion transport rates are controlled by various hormones (e.g. aldosterone, vasopressin), the tubular fluid composition (e.g. ion concentration, pH) and the tubular flow-rate.

We study pathways and mechanisms that control the abundance and activity of ion transporting proteins along the distal nephron in vivo under various physiological and/or pathophysiological conditions. The specific role of given ion transporting proteins is also investigated in genetically modified mice, representing murine models for human hereditary diseases. Experiments in vitro on mouse renal cell lines complement the in vivo studies. The effects of our experimental procedures are assessed by a combination of morphological (e.g. light- and electron microscopy), biochemical (e.g. cell-surface biotinylation, immunoblotting), molecular-biological (e.g. real-time RT-PCR, heterologous expression of mRNA) and electro-physiological (e.g. amiloride-sensitive sodium currents) techniques.

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