Renal and hormonal responses were studied in a group of healthy individuals fed, in
random order, for three weeks, a vegetable protein diet (N = 10), an animal protein
diet (N = 10), or an animal protein diet supplemented with fiber (N = 7), all containing
the same amount of total protein (chronic study). In seven additional subjects the
acute renal, metabolic and hormonal response to ingestion of a meat or soya load of
equivalent total protein content was investigated (acute study). In the chronic study
GRF, RPF and fractional clearance of albumin and IgG were significantly higher on
the animal than the vegetable protein diets (GFR: 121 +/- 4 vs. 111 +/- 4 ml/min/1.73
m2, P less than 0.001; RPF: 634 +/- 29 vs. 559 +/- 26 ml/min/1.73 m2, P less than
0.001; theta alb: 19.5 +/- 3.1 vs. 10.2 +/- 1.6 x 10(-7), P less than 0.01; theta
IgG: 11.6 +/- 3.1 vs. 7.5 +/- 1.7 x 10(-7), P less than 0.05). Renal vascular resistance
was lower on the animal than vegetable protein diet (82 +/- 5 vs. 97 +/- 5 mmHg/min/liter;
P less than 0.001). Fiber supplementation to APD did not have any effect on the renal
variables measured which were indistinguishable from APD. In the acute study, GFR
and RPF both rose significantly by approximately 16% (P less than 0.005) and approximately
14% (P less than 0.05), respectively, after the meat load, while RVR fell by approximately
12% (P less than 0.05). There were no significant changes in these parameters following
the soya load.(ABSTRACT TRUNCATED AT 250 WORDS)