Abstract
In chronic glomerulonephritis with hypercreatininemia (Group 1), there was a significant correlation between the changes in urinary protein excretion (Uprot•V) and those in GFR during both quiet standing and walking.
In chronic glomerulonephritis without hypercreatininemia (Group 2), there was a significant correlation between the changes in Uprot•V and those in GFR during quiet standing, but no correlation during walking. In nephrotic syndrome with definite evidence of chronic glomerulonephritis on renal biopsy (Group 3), there seemed to be a good correlation between the changes in Uprot•V and these in GFR during both quiet standing and walking, but in nephrotic syndrome with minimal changes on renal biopsy (Group 4), no correlation was found during both quiet standing and walking.
Relative clearances of urinary protein estimated by acrylamide gel electro-phoresis and immunodiffusion method did not differ among supine bed rest, quiet standing and walking, although urinary protein excretion was either increased or decreased by postural changes.
Relative clearances of urinary protein showed that permeability of protein through the glomerular membrane was more selective in Group 2 than in Group I of chronic glomerulonephritis, and that also more selective in Group 4 than in Group 3 of nephrotic syndrome.
The changes in protein excretion by postural changes were explained by the concurrent decrease of GFR in Groups 1 and 2 of chronic glomerulonephritis, and also in Group 3 of nephrotic syndrome.
On the other hand, the alterations by postural changes in tubular reasbsorptive capacity for protein might determine to some extent protein escape into urine in Group 4 of nephrotic syndrome.
