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 sub jected to 1 1/13 nephrectomy (4/6 Nx) fed either a normal (16%) or a l ow-protein (8%) diet. At 4 weeks postsurgery, ablated rats exhibited m odest elevations in blood pressure but had neither significant protein uria nor evidence of glomerular damage. Following injection of aggBSA into 4/6 Nx rats (16% diet) there was a marked increase in mesangial l ocalization at 4 h compared with control animals, followed by rapid cl earance over 4-8 h, in keeping with increased trafficking in this mode l. The increased trafficking was significantly reduced by dietary prot ein restriction with 4/6 Nx rats fed an 8% protein diet exhibiting mes angial kinetics not significantly different from control animals. Cont rol animals exhibited identical kinetics irrespective of diet. In sepa rate studies, the 8% protein diet significantly reduced proteinuria an d glomerulosclerosis when compared with untreated animals when studied at 30 weeks postsurgery.