Albumin appearing in urine will be due to-: (A) It is of small size, (B) Increase in GFR, (C) Loss of charge in glomerulus, (D) None of the above
Answer is C. The molecular diameter of the plasma protein albumin is only about 6 nanometers, whereas the pores of the glomerular membrane are thought to be about 8 nanometers (80 angstroms). Albumin is restricted from filtration, however, because of its negative charge and the electrostatic repulsion exeed by negative charges of the glomerular capillary wall proteoglycans.