[Aptamers: a novel approach to intervention studies and development of novel therapeutic approaches].

A rapidly growing number of factors is identified that might contribute to disease. To characterize the pathogenetic relevance of a particular factor, specific intervention studies in vivo appear necessary. The present discussion deals with a new class of inhibitors, i.e. aptamers. Aptamers (derived from the latin word "aptus" = fitting) are short DNA or RNA oligomers which can bind to a given ligand with high affinity and specificity due to their particular three-dimensional structure and which may thereby, for example, antagonize the biological function of the ligand. Aptamers have been generated against a large variety of molecules ranging from amino acids to complex proteins and even disaccharides. Using platelet-derived growth factor (PDGF) and an experimental mesangioproliferative glomerulonephritis as a model, we describe the in vivo effects of an antagonistic aptamer against PDGF-B. Such studies will greatly aid the identification of the biological role of particular mediators and ultimately the design of novel therapeutic strategies.