[The determination of the concentration of antithrombin III in the urine]

The authors developed the special enzyme immunoassay technique for the detection of the urinary antitrombin III (AT-III) levels. Sensitivity of the method was 7.8 ng/ml. The study lasted for 2 hrs. The levels of AT-III were studied in the circadian human urine in health, in physiological and nephropathy-complicated pregnancy, as well as in patients with gastroduodenal ulcer-induced bleeding. There was a 34.1-fold increase in the urinary AT-III levels in pregnant females with Stages II-III nephropathy and a 17.3-fold increase in those who sustained the resection of the stomach, which could be explained by proteinuria and abnormal resorption of AT-III in the proximal tubules of the kidney.