Urinary protein thiols in different grades of proteinuria.

Total thiol status of plasma, especially thiol groups over protein contributes maximum to the plasma antioxidant status of the body. Serum protein thiols were found to be decreased in various disease conditions including chronic renal failure patients. Only few studies determined the levels of urinary protein thiols in disease conditions. The current study was designed to know the levels of urinary protein thiols in patients with different grades of proteinuria. The study was conducted on urine of 40 healthy controls and 61 cases with proteinuria. Based on proteinuria cases were further divided into two groups; group I - microproteinuria (150-300 mg protein/d), 32 cases, group II - frank proteinuria (>300 mg protein/d), 29 cases. Urinary thiol levels were determined by spectrophotometric method using dithionitrobenzoic acid. A significant decrease (p<0.01) in urinary thiol in group I and group II cases was observed in present study and this decrease was associated with proteinuria.