Urinary excretion of brush-border enzymes of the proximal renal tubules in pregnant women with hypertensive disorders.

OBJECTIVES: The aim of our study was to evaluate urinary excretion of three brush border enzymes: gamma-glutamyl transferase, alanine aminopeptidase, and leucyl aminopeptidase in pregnant women with various types of hypertensive disorders. MATERIAL AND METHODS: The study included 120 pregnant women, further subdivided into four groups: 41 women at ≥ 20 weeks gestation with gestational hypertension, 28 women > 20 weeks of pregnancy with preeclampsia, 21 women with chronic hypertension identified > 20 weeks of pregnancy and 30 healthy pregnant controls. RESULTS: No significant differences in urinary levels of all three of the brush border enzymes were found between the groups. Also, there was no correlation between enzyme concentration in the urine and blood pressure values in any of the analyzed groups of pregnant women. CONCLUSIONS: The obtained results suggest no damage to the brush border of the proximal kidney tubules in the early stages of disorders associated with increased blood pressure during pregnancy.

Urinary lysosomal enzyme excretion in pregnant women with hypertensive disorders.

BACKGROUND: The authors assessed proximal renal tubular dysfunction and/or damage in pregnant women with various types of hypertension by measuring the three urinary lysosomal enzyme levels: N-acetyl-ß-d-glucosaminidase (NAG), arylsulfatase A and ß-glucuronidase. METHODS: The study consisted of 120 pregnant women divided into four groups: 41 women in 20th week of gestation or more, with pregnancy-induced hypertension (PIH group), 28 pregnant women after 20 weeks of pregnancy with pre-eclampsia (PE group), 21 pregnant women with chronic hypertension, identified before 20th week of pregnancy (CH group) and 30 healthy, pregnant women (healthy controls (HC) group). RESULTS: Statistical analysis showed significantly higher levels of all the three of lysosomal enzymes in the urine of patients with PE compared with the healthy pregnant women, pregnant women with PIH and the ones with chronic hypertension. Additionally, significantly higher values of NAG were found in the group of pregnant women with PIH compared with healthy pregnancies. No correlation was found between the concentration of enzymes in urine and values of blood pressure in any of the analyzed groups of pregnant women. CONCLUSIONS: The authors conclude that higher values of all the studied enzymes in PE group, in the comparison with the other groups, indicate proximal tubular damage at the cellular level. The lack of correlation between the concentration of lysosomal enzymes and blood pressure suggests that the damage to these parts of kidney is complex. In addition, mechanisms other than hypertension realizing intracellular enzymes may be involved in this process.