Renal function and urinary urokinase in hypertensive and diabetic pregnancies

Urokinase (u-PA) dissolves and removes fibrin deposits in the renal secretory pathways in various renal diseases. During pregnancy nephropathy creates a problem in preeclampsia and diabetes, but the underlying mechanism of glomerular damage is different. Preeclamptic nephropathy is characterized as 'glomerular endotheliosis' with hypertrophy of the intracapillary cells, and diabetic nephropathy as 'glomerulosclerosis' with hyaline deposits. The role of fibrin deposition for the etiology of renal damage in preeclampsia is controversial. Changes of the urinary secretion of u-PA may reflect the type of glomerular damage. Our hypotheses were that renal insufficiency is associated with a low u-PA activity in both conditions, and that severe disease is parallel to declining concentrations of u-PA. We compared the glomerular filtration rate, S-Creatinine and S-Urate with urinary u-PA excretion in 24 hypertensive and 20 diabetic pregnant women. In diabetic patients, a low u-PA concentrations was associated with an impaired renal function. In hypertensive pregnancy, the u-PA excretion did not reflect the severity of the hypertensive disease or renal function. No association was found between u-PA excretion and renal function post partum in any group. We conclude that renal urokinase activity plays a role for renal function in diabetic but not in hypertensive pregnancy.