Glomerular basement membrane: In vitro studies of water and protein permeability

摘要: The glomerular basement membrane (GBM) is an integral structural component of the filter, but its contribution to hydraulic and macromolecular permeability properties glomerulus has been subject much controversy. We have modified previously reported methods develop a technique with which study filtration microgram quantities isolated GBM in vitro at physiological pressures. Rat glomeruli were sieved, cells removed N-laurylsarcosine DNase. (150 micrograms; greater than 95% pure) added mini-ultrafiltration cell consolidated under pressure form continuous filter base cell. Water flux was identical inulin clearance applied pressures less 150 mmHg increased progressive increments transmembrane pressure. Hydraulic conductivity inversely related prevailing gradient. depended on albumin concentration manner that not monotonic, being lower 4 g/dl 0 or 8 g/dl. When plasma utilized as retentate, fractional over twice immunoglobulin G, each protein higher intact glomerulus. On basis these results, both individual layer are for large quantitative differences between suggest major cellular elements properties.