[Endothelial dysfunction and apoptosis at early stage of chronic kidney disease].

AIM: To study changes in apoptosis and endothelial function in patients with chronic kidney disease (CKD) stage I-IIIb (CKDsI-IIIb). MATERIAL AND METHODS: A complex of biochemical, enzyme immunoassay and device investigations was used to examine 128 patients with CKDsI-IIIb. RESULTS: In CKD stage I reduction of endothelium-dependent vasodilation (EDV) was detected in 34% patients, in stage II -- in 52 %, in stage IIIa -- y 52 %, in stage IIIb - in 70%. An EDV decrease was associated with glomerular filtration rate (GFR), a homocysteine level and hemodynamic factors. Elevation of endothelin-1 (ET-1) level was seen in CKDsI in 41 %, in CKDsII - in 54 %, in CKDsIIIa - in 70 %, in stage IIIb - in 83% patients. A negative correlation was observed between the level of ET-1 and GFR and positive - with diurnal proteinuria. A significant rise of annexin A5 concentration versus normal was detected as early as in CKDsI (1,14 +/- 0,68 ng/ml). In CKDsII annexin A5 was 2,61 +/- 0,75 ng/ml, in CKDsIIIa - 3,75 +/- 0,93 ng/ml and in CKDsIIIb - 5,16 +/- 1.01 ng/ml. Negative correlations were found between annexin A5 level and GFR, a maximal growth of volumetric blood flow rate in skin vessels in the acetylcholine test, positive correlations with systolic blood pressure, body mass index. CONCLUSION: The levels of ET-1 and annexin A5 are factors having an independent impact on EDV in patients with CKDsI-II.

[The level of endothelin-1 and reactivity of skin microvessels in patients with early stages of chronic kidney disease].

AIM: To evaluate endothelin-1 (ET-1) levels and to characterize reflex vasomotor reactions of skin vessels in distant exposure to cold in patients with chronic kidney disease (CKD) of stage I and II. MATERIAL AND METHODS: Glomerular filtration rate (GFR) was calculated by MDRD formula for 40 healthy subjects (mean age 39.2 +/- 2.0 years) and 147 CKD patients (mean age 41.4 +/- 1.8 years). All the patients were also exposed to the cold test (a modified variant). RESULTS: Patients with CKD stage I demonstrated a 35.1% fall in blood flow rate (Qas) in response to cold stimulus, patients of stage II--a 42.2% fall, healthy patients--a 19.3%. CKD patients of stage I and II retained a Qas fall for 3 min after exposure to cold, while healthy subjects resumed skin blood circulation immediately after exposure to cold. Blood plasma ET-1 concentration in healthy subjects was 0.239 +/- 0.055 fmol/ml, in stage I CKD patients--0.334 +/- 0.066 fmol/l, in stage II CKD patients--0.422 +/- 0.041 fmol/l. Relationships were found between ET-1 level and GFR (Rs = 0.242; p < 0.05), 24 h proteinuria (Rs = 0.375; p < 0.003) and Qas% in the cold test (Rs = -0.389; p < 0.003) as well as time of recovery of the background Qas (Rs = -0.311; p < 0.003). CONCLUSION: Dysfunction of autonomic nervous system at early stages of CKD may arise by means of activation of ET-1 synthesis in response to enhancement of sympathetic impacts.