NT-ProBNP levels, water and sodium homeostasis in healthy men: effects of 7 days of dry immersion.

Immersion is a useful tool for studying fluid-volume homeostasis. Natriuretic peptides play a vital role in renal, humoral, and cardiovascular regulation under changing environmental conditions. We hypothesized that dry immersion would rapidly induce a new steady state for water and sodium metabolism, and that serum NT-proBNP levels, a proxy measure for brain natriuretic peptide (BNP), would decrease during long-term dry immersion and increase during recovery. Eight healthy young men were studied before, during, and after 7 days of dry immersion. Body weight, water balance, and plasma volume changes were evaluated. Plasma and serum samples were analyzed for active renin, NT-proBNP, aldosterone, electrolytes, osmolality, total protein, and creatinine. Urine samples were analyzed to determine levels of electrolytes, osmolality, creatinine, and free cortisol. A stand test was performed before and after dry immersion to evaluate cardiovascular deconditioning. Long-term dry immersion induced acute changes in water and sodium homeostasis on day 1, followed by a new steady state. Plasma volume decreased significantly during dry immersion. The serum levels of NT-proBNP increased significantly in recovery (10 +/- 3 ng/L before dry immersion vs. 26 +/- 5 ng/L on the fourth recovery day). Heart rate in the standing position was significantly greater after immersion. Results suggest that chronic dry immersion rapidly induced a new level of water-electrolyte homeostasis. The increase in NT-proBNP levels during the recovery period may be related to greater cardiac work and might reflect the degree of cardiovascular deconditioning

IDENTIFICATION OF BIOMARKERS OF RENAL PARENCHYMA DAMAGE IN THE URINE OF PATIENTS WITH CHRONIC PYELONEPHRITIS BY ELISA AND MASS SPECTROMETRY METHODS

We performed clinical observations and laboratory examination of 22 patients with chronic pyelonephritis (chronic renal failure, CRF) and 30 healthy individuals. The patients with CRF were examined twice. The first group (Group I) included patients with exacerbation of the disease. The comparison series (Group II) was represented by the same patients who were examined 1.5-3 months after completion of treatment, without clinical exacerbation of chronic pyelonephritis (CPN). Laboratory signs of acute renal damage were not detectable in all the patients examined. Concentrations of VEGF, MCP-1, IL-8 and IL-18 were determined in urine samples of all examined persons by ELISA technique. Protein spectrum of urine was assessed in six patients from Group I, and in six cases of Group II by means of mass spectrometry, using Agilent 1100 chromatographic device, and LTQ-FT Ultra hybrid mass spectrometer. The results of parallel determination of urine proteins by the two methods have shown that the evolving CPN exacerbation is associated with local secondary immune deficiency at the level of renal tubular urothelium. Determination of urine proteome by means of mass spectrometry in exacerbating disease allows identify the proteins associated with damage to epithelial lining of renal tubules and development of local immune response

Detection of renal tissue and urinary tract proteins in the human urine after space flight.

The urine protein composition samples of ten Russian cosmonauts (male, aged of 35 up to 51) performed long flight missions and varied from 169 up to 199 days on the International Space Station (ISS) were analyzed. As a control group, urine samples of six back-up cosmonauts were analyzed. We used proteomic techniques to obtain data and contemporary bioinformatics approaches to perform the analysis. From the total number of identified proteins (238) in our data set, 129 were associated with a known tissue origin. Preflight samples contained 92 tissue-specific proteins, samples obtained on Day 1 after landing had 90 such proteins, while Day 7 samples offered 95 tissue-specific proteins. Analysis showed that consistently present proteins in urine (under physiological conditions and after space flight) are cubilin, epidermal growth factor, kallikrein-1, kininogen-1, megalin, osteopontin, vitamin K-dependent protein Z, uromodulin. Variably present proteins consists of: Na(+)/K(+) ATPase subunit gamma, β-defensin-1, dipeptidyl peptidase 4, maltasa-glucoamilasa, cadherin-like protein, neutral endopeptidase and vascular cell adhesion protein 1. And only three renal proteins were related to the space flight factors. They were not found in the pre-flight samples and in the back-up cosmonaut urine, but were found in the urine samples after space flight: AFAM (afamin), AMPE (aminopeptidase A) and AQP2 (aquaporin-2). This data related with physiological readaptation of water-salt balance. The proteomic analysis of urine samples in different phases of space missions with bioinformation approach to protein identification provides new data relative to biomechemical mechanism of kidney functioning after space flight

Microalbuminuria (mg/day) during Space Mission.

<p>Data from Cirillo et al. (28).</p

Renal proteins in the prime and back-up cosmonauts’ urine before and after space flight.

<p>Renal proteins in the prime and back-up cosmonauts’ urine before and after space flight.</p