Cardiovascular system parameters in participants of Arctic expeditions.

OBJECTIVES: A method of continuous heart rate (HR) and blood pressure (BP) recording was used for the evaluation of the cardiovascular system parameters in participants of short-term (<1 month) high-latitude expeditions, in comparison with the parameters of residents of Central Russia and the Arctic region. MATERIAL AND METHODS: A dynamic examination of participants of Arctic expeditions (30 men, residents of middle-latitude regions, aged 46.7±1.7 years), workers permanently living in Central Russia (the Moscow region, 44 men, aged 46.7±1.0 years) and residents of the North (the Murmansk region, 35 men, aged 46.6±1.3 years) was performed. The authors used a spiroartheriocardiorythmograph allowing the parallel recording of HR, BP, spectral characteristics of HR variability (HRV) and the variability of systolic BP (sBP) and diastolic BP (dBP), cardiac performance parameters, and spontaneous baroreflex sensitivity (BRS). The parameters were recorded at rest, in a sitting position, over 2 min. RESULTS: The basic clinical parameters (HR, BP and cardiac performance) did not differ in the workers living in different climatic zones. However, the residents of the North demonstrated a lower total power (TP) of the dBP variability spectrum and a lower relative power of the high-frequency (HF) range in both the sBP and dBP variability spectra. The participants of expeditions to the North had a lower TP of the HRV spectrum (in comparison with both control groups) that did not change during the expeditions; BRS was reduced, while the TP of the sBP spectrum was increased in comparison with the corresponding parameters obtained from the residents of circumpolar regions, and decreased during the expedition in parallel with a decrease in the sBP values. The TP of both the sBP and dBP variability spectra, as well as the power of the HF range in these spectra, were similar in the participants of expeditions to those obtained from the residents of Central Russia, and they considerably surpassed the corresponding parameters in the northerners surveyed. CONCLUSIONS: The revealed peculiarities of the cardiovascular system in the participants of high-latitude expeditions can be considered as correlates of positive, and adequate in terms of the physiological value, adaptive shifts in the autonomous regulation of the cardiovascular system. Int J Occup Med Environ Health. 2020;33(6):819-28.

Differential procoagulant activity of microparticles derived from monocytes, granulocytes, platelets and endothelial cells: impact of active tissue factor.

: Microparticles released by activated/apoptotic cells exhibit coagulation activity as they express phosphatidylserine and some of them - tissue factor. We compared procoagulant properties of microparticles from monocytes, granulocytes, platelets and endothelial cells and assessed the impact of tissue factor in observed differences. Microparticles were sedimented (20 000g, 30 min) from the supernatants of activated monocytes, monocytic THP-1 cells, granulocytes, platelets and endothelial cells. Coagulation activity of microparticles was examined using plasma recalcification assay. The size of microparticles was evaluated by dynamic light scattering. Tissue factor activity was measured by its ability to activate factor X. All microparticles significantly accelerated plasma coagulation with the shortest lag times for microparticles derived from monocytes, intermediate - for microparticles from THP-1 cells and endothelial cells, and the longest - for microparticles from granulocytes and platelets. Average diameters of microparticles ranged within 400-600 nm. The largest microparticles were produced by endothelial cells and granulocytes, smaller - by monocytes, and the smallest - by THP-1 cells and platelets. The highest tissue factor activity was detected in microparticles from monocytes, lower activity - in microparticles from endothelial cells and THP-1 cells, and no activity - in microparticles from platelets and granulocytes. Anti-tissue factor antibodies extended coagulation lag times for microparticles from monocytes, endothelial cells and THP-1 cells and equalized them with those for microparticles from platelets and granulocytes. Higher coagulation activity of microparticles from monocytes, THP-1 cells and endothelial cells in comparison with microparticles from platelets and granulocytes is determined mainly by the presence of active tissue factor.

Decreased adipose tissue zinc content is associated with metabolic parameters in high fat fed Wistar rats.

BACKGROUND: Limited data on adipose tissue zinc content in obesity exist. At the same time, the association between adipose tissue zinc content and metabolic parameters in dietary-induced obesity is poorly studied. Therefore, the primary objective of this study is to assess adipose tissue zinc content and its association  with morphometric parameters, adipokine spectrum, proinflammatory cytokines, and apolipoprotein profile in high fat fed Wistar rats. METHODS: A total of 48 adult female Wistar rats were used in the present study. Rats were fed either control (10% of fat) or high fat diet (31.6% of fat). Adipose tissue zinc content was assessed using inductively coupled plasma mass spectrometry. Rats' serum was examined for adiponectin, leptin, insulin, interleukin-6, and tumor necrosis factor-α using enzyme-linked immunosorbent assay kits. Serum glucose and apolipoprotein spectrum were also evaluated. RESULTS: High fat feeding resulted in a significant 34% decrease in adipose tissue zinc content in comparison to the control values. Fat pad zinc levels were significantly inversely associated with morphometric parameters, circulating leptin, insulin, tumor necrosis factor-α levels and HOMA-IR values. At the same time,      a significant correlation with apolipoprotein A1 concentration was observed. CONCLUSIONS: Generally, the obtained data indicate that (1) high fat feeding results in decreased adipose tissue zinc content; (2) adipose tissue zinc content is tightly associated with excessive adiposity, inflammation, insulin resistance and potentially atherogenic changes.

Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes.

BACKGROUND: A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the influence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in Wistar rats. METHODS: 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the first and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA) in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits. RESULTS: Intragastric administration of zinc asparaginate significantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats' organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity. CONCLUSIONS: The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.