Abstract
A method for quantitative analysis of urinary proteins by SDS-polyacrylamide disc gel electrophoresis, using a certain amount of cytochrome-c as an internal standard, was established to reveal microproteinuria, and the characteristic features of urinary proteins in diabetic nephropathy.
Correlation between the urinary albumin content measured by radioimmunoassay (y) and by quantitative polyacrylamide disc gel electrophoresis (x) was shown to be represented by the equation: y=0.040+0.664x (r=0.959. p<0.01).
Microproteinuria, containing more than 176.8μg/ml of protein, was detected in 53.6% of diabetics whose urine was negative for protein by albustix.
Duration of diabetes was longer and incidence of hypertension was higher in diabetics with microproteinuria than in diabetics with normoproteinuria.
The ratio of albumin to total protein was larger and the ratio of low-molecular-weight protein was smaller in diabetics with microproteinuria than in diabetics with normoproteinuria. The ratio of high-molecular-weight protein to total protein tended to be increased in diabetics with microproteinuria and more so in diabetics with macroproteinuria compared with diabetics with normoproteinuria.
