Impaired Albumin Uptake and Processing Promote Albuminuria in OVE26 Diabetic Mice

Figure 1

Urine excretion of injected TR-albumin and FITC-dextran. (a) Twenty-four hours after TR-albumin injection, urine samples of OVE mice contain 7-fold more fluorescence than FVB urine. (b) After NAP5 spin column fractionation the first two high molecular weight fractions had 23-fold more fluorescence in OVE urine than in FVB urine. (c) G75 column fractionation profiles of urine show that the high molecular weight peak of OVE urine elutes with the same peak as standard BSA. No TR-albumin peak at this MW could be seen in FVB urine. (d) Twenty-four hours after FITC-dextran injection, urine samples of OVE mice contain 3-fold more fluorescence than FVB urine. (e) After NAP5 spin column fractionation the first two high molecular weight fractions from OVE urine had 3-fold more FITC fluorescence than from FVB urine. (f) G75 column fractionation profiles of urine show that the high molecular weight peak elutes 2 fractions before the standard BSA peak. Arrows indicate peaks for bovine serum albumin (BSA, 66 kDa), carbonic anhydrase (CA, 30 kDa), and cytochrome C (CC, 12 kDa). For panels (a) and (b) results are the average from 4 OVE and 5 FVB mice. Panel (c) results are typical of 3 OVE and 3 FVB mice. Panels (d) and (e) results are the average from 5 OVE and 5 FVB mice. Panel (f) results are typical of 2 OVE and 2 FVB mice. Symbols indicate that OVE values are greater than FVB (, , and $ indicates a trend of ).