Biosynthetic studies with isolated kidney glomeruli

Glomeruli were isolated from rat kidneys and were found active in protein and glycoprotein synthesis in vitro. The incorporation of proline, galactose and fucose into macromolecules was linear for at least 8 h. The intracellular pool of free proline and lysine was 52 and 32 nmol/mg glomerular protein respectively. Vinblastin and cytochalasin B, two agents which interfere with normal cellular secretory processes, inhibited galactose and fucose incorporation, possibly by a feedback mechanism. Experimental nephrotic syndrome was induced in rats by the injection of puromycin aminonucleoside; the rate of proline and galactose incorporation was reduced in glomeruli isolated from the nephrotic animals. The system of isolated glomeruli is deemed suitable for future studies of selected kidney diseases which affect the glomeruli.