Soy protein increases glomerular filtration rate in dogs with normal or reduced renal function

In mammals, protein ingestion increases the glomerular filtration rate (GFR ), an effect which has been incriminated as a risk factor in progression of renal disease. Some studies suggest that a postprandial increase in GFR is absent or mild with vegetable proteins compared to animal proteins. The ob jective of this experiment was to determine whether vegetable (soy) protein had different effects than animal protein on GFR in dogs with normal or re duced renal function. A trial was conducted in which GFR was measured in fo ur dogs with normal kidney function and seven dogs with reduced renal mass before and after administering protein. Normal dogs were fed four protein s ources (casein, soy meal, soy flakes and purified soy protein). Dogs with r educed renal mass were fed three protein sources (casein, purified soy prot ein and pork liver). All proteins significantly (P < 0.05) increased the GF R in both groups except for casein (P = 0.066) in normal dogs. Proteins did not differ significantly in the magnitude of the increase in GFR that was induced. This study indicates that soy proteins in dogs have the same effec t on GFR as animal-source proteins, which is contrary to reports of effects in humans.