Mesangial kinetics after partial nephrectomy in rats fed a normal or a low-protein diet

Mesangial kinetics of aggregated BSA (aggBSA) were studied in rats subjected to 1 1/3 nephrectomy (4/6 Nx) fed either a normal (16%) or a low-protein (8%) diet. At 4 weeks postsurgery, ablated rats exhibited modest elevations in blood pressure but had neither significant proteinuria nor evidence of glomerular damage. Following injection of aggBSA into 4/6 Nx rats (16% diet) there was a marked increase in mesangial localization at 4 h compared with control animals, followed by rapid clearance over 4-8 h, in keeping with increased trafficking in this model. The increased trafficking was significantly reduced by dietary protein restriction with 4/6 Nx rats fed an 8% protein diet exhibiting mesangial kinetics not significantly different from control animals. Control animals exhibited identical kinetics irrespective of diet. In separate studies, the 8% protein diet significantly reduced proteinuria and glomerulosclerosis when compared with untreated animals when studied at 30 weeks postsurgery.