[Novel insights into the glomerular structure].

In recent years, significant progress has been made in understanding the structure and pathomechanisms of the glomerulus of the kidney. Some of these more recent advances and open questions are discussed in this review: 1.) The functioning of the glomerular filter still remains incompletely understood, although the microanatomy and molecular biology of the glomerular filter has been investigated in great detail. 2.) Vascular endothelial growth factor (VEGF) has been shown to mediate spacial clues that are essential for the polarized distribution of the cells within the glomerulus. 3.) A novel theory of the subpodocyte space offers a novel explanation for the flux of VEGF from the podocytes against the bulk flow of the filtrate to the glomerular endothelial cells. 4.) Novel transgenic mouse models have enabled us to investigate the functional role not only of podocytes but more recently also of parietal cells which might serve as an intrarenal progenitor cell population. 5.) Parietal cells play a so far under-recognized role in various glomerular diseases. In rapid progressive glomerulonephritis, cellular crescents originate predominantly from parietal cells.