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Hemorheological responses to progressive resistance exercise training in healthy young males.

Summary Background This study aimed to explore the effects of progressive resistance exercise training (PRET) on hemorheology. Material/Methods Exercise sessions included 1–3 sets of 8–12 repetitions at 40–60% of 1-repetition maximum (1-RM) for 3 weeks and at 75–80% of 1-RM during weeks 4–12. Red blood cell (RBC) deformability and aggregation were determined by ektacytometry, plasma and whole blood viscosities (WBV) by rotational viscometry. Lactate concentration was evaluated by an analyzer and fibrinogen was evaluated by coagulometry. Plasma total oxidant/antioxidant status was measured by colorimetry. Results Following an acute increase after exercise on the first day, RBC deformability was elevated during weeks 3 and 4 (p=0.028; p=0.034, respectively). The last exercise protocol applied in week 12 again caused an acute increase in this parameter (p=0.034). RBC aggregation was increased acutely on the first day, but decreased after that throughout the protocol (p<0.05). At weeks 4 and 12 pre-exercise measurements of WBV at standard hematocrit and plasma viscosity were decreased (p=0.05; p=0.041, respectively), while post-exercise values were increased (p=0.005; p=0.04, respectively). Post-exercise WBV at autologous hematocrit measured at week 12 was increased (p=0.01). Lactate was elevated after each exercise session (p<0.05). Fibrinogen was decreased on the third week (p<0.01), while it was increased on the 4th week (p=0.005). Plasma antioxidant status was increased at week 3 (p=0.034) and oxidative stress index was decreased at week 4 (p=0.013) after exercise. Conclusions The results of this study indicate that PRET may have positive effects on hemorheological parameters.

Increased red blood cell deformability and decreased aggregation as potential adaptive mechanisms in the slow coronary flow phenomenon.

ObjectiveAt present, the precise pathophysiology of the slow coronary flow phenomenon (SCFP) is still unknown and there is no consensus as to how it should be treated. The rheological factors affect the clinical course of various cardiovascular diseases. We studied the intrinsic properties of blood in the SCFP. Materials and methodsTwenty-six SCFP patients who had angiographically confirmed SCFP, and had otherwise normal epicardial coronary arteries, were included in our study, as were 30 healthy individuals with normal results from arteriography. Red blood cell (RBC) deformability, aggregation, whole-blood viscosity at both native and standard (40%) hematocrit, and plasma viscosity were determined in each individual. The results were analyzed using a Mann–Whitney U-test, an unpaired t-test, and a &khgr;2-test, where appropriate. ResultsThe mean thrombolysis in myocardial infarction frame count was significantly higher in SCFP patients than in the controls. RBC deformability measured at five different shear rates was significantly higher in SCFP patients than in the controls. The RBC aggregation index was lower in SCFP patients. There were no statistically significant differences in RBC aggregation half-time (t1/2) and aggregation amplitude, whole-blood viscosity, and plasma viscosity between the two groups. ConclusionThe SCFP is associated with increased RBC deformability and decreased RBC aggregation. These hemorheological alterations, possibly also contributing factors in limiting the pathogenesis, can especially serve as beneficial adaptive mechanisms in the SCFP.

Effect of Sulfite Treatment on Erythrocyte Deformability in Young and Aged Rats

It is known that aging is associated with marked effects on integrity and function of cell membrane. These effects may also be exacerbated by exogenous chemicals, e.g. sulfite. Thus, the aim of this paper is to examine the influence of sulfite on hemorheological and related hematological parameters in rats of various ages. In this study, male Wistar rats at the age of 3 and 18 months were used and the following parameters were evaluated: Mean Cell Volume (MCV), Mean Corpuscular Hemoglobin Concentration (MCHC), Red blood Cell (RBC) deformability and aggregation. The results show that aging is associated with a decrease in RBC deformability and MCHC, an increase in MCV. Sulfite administration significantly increased RBC deformability in both young and aged rats. Although MCHC was decreased in young rats, it was increased in aged rats in response to sulfite exposure. Additionally, sulfite induced a decrement in MCV of aged rats. Neither aging nor sulfite treatment caused significant alterations in RBC aggregation parameters in all experimental groups. In conclusion, these findings suggest that RBC deformability impairs with age and sulfite has ameliorating effects on RBC deformability in both young and aged rats.

Effect of thrombocytapheresis on blood rheology in healthy donors: Role of nitric oxide

Platelet transfusions are increasingly being used to treat thrombocytopenic conditions. Because of anticoagulation, changes in blood composition and extracorporeal circulation, donor apheresis may cause alterations in hemorheology. This study aimed at investigating the effects of thrombocytapheresis on donor blood rheology. The effect of nitric oxide (NO) on donor red blood cell (RBC) deformability after thrombocytapheresis was also studied. Platelets were collected by a Haemonetics MCS 3p cell seperator. Blood samples were obtained before and 15 min after thrombocytapheresis. RBC deformability and aggregation were measured using an ektacytometer, whole blood viscosity (WBV) was determined with a cone-plate rotational viscometer. Donor RBCs were shown to be less deformable at all stress levels except 0.30 Pa after thrombocytapheresis and NO donor sodium nitroprusside (SNP, 10(-6) M) reversed the reduced deformability caused by thrombocytapheresis. It was observed that donor apheresis induces a decrement in RBC aggregation and WBV measured at standard hematocrit (Hct). No significant alterations were observed in WBV values determined at native Hct values. Thrombocytapheresis also resulted in a decrement in fibrinogen, total protein, cholesterol and albumin levels whereas Hct was found to be increased and serum glucose, triglyceride, hemoglobin levels unaltered after apheresis. These results suggest that, thrombocytapheresis causes alterations in hemorheological parameters and hence in the perfusion of the microvasculature of the donors and NO appears to have a protective effect on the impairment observed in RBC deformability.

Altitude training induced alterations in erythrocyte rheological properties: A controlled comparison study in rats

Altitude training is frequently used by athletes to improve sea-level performance. However, the objective benefits of altitude training are controversial. This study aimed to investigate the possible alterations in hemorheological parameters in response to altitude training. Sprague Dawley rats, were divided into 6 groups: live low-train low (LLTL), live high-train high (LHTH), live high-train low (LHTL) and their controls live high and low (LHALC), live high (LHC), live low (LLC). LHC and LHTH groups were exposed to hypoxia (15% O2, altitudes of 3000 m), 4 weeks. LHALC and LHTL were exposed to 12 hours hypoxia/normoxia per day, 4 weeks. Hypoxia was maintained by a hypoxic tent. The training protocol corresponded to 60-70% of maximal exercise capacity. Rats of training groups ran on treadmill for 20-30 min/day, 4 days/week, 4 weeks. Erythrocyte deformability of LHC group was increased compared to LHALC and LLC. Deformability of LHTH group was higher than LHALC and LLTL groups. No statistically significant alteration in erythrocyte aggregation parameters was observed. There were no significant relationships between RBC deformability and exercise performance. The results of this study show that, living (LHC) and training at altitude (LHTH) seems more advantageous in hemorheological point of view.

Exercise and DHA Prevent the Negative Effects of Hypoxia on EEG and Nerve Conduction Velocity

It is known that hypoxia has a negative effect on nervous system functions, but exercise and DHA (docosahexaenoic acid) have positive effect. In this study, it was investigated whether exercise and/or DHA can prevent the effects of hypoxia on EEG and nerve conduction velocity (NCV). 35 adult Wistar albino male rats were divided into five groups (n=7): control (C), hypoxia (H), hypoxia and exercise (HE), hypoxia and DHA (HD), and hypoxia and exercise and DHA (HED) groups. During the 28-day hypoxia exposure, the HE and HED groups of rats were exercised (0% incline, 30 m/min speed, 20 min/day, 5 days a week). In addition, DHA (36 mg/kg/day) was given by oral gavage to rats in the HD and HED groups. While EEG records were taken before and after the experimental period, NCV records were taken after the experimental period from anesthetized rats. Data were analyzed by paired t-test, one-way ANOVA, and post hoc Tukey test. In this study, it was shown that exposure to hypoxia decreased theta activity and NCV, but exercise and DHA reduced the delta activity, while theta, alpha, beta activities, and NCV were increased. These results have shown that the effects of hypoxia exposure on EEG and NCV can be prevented by exercise and/or DHA.

The effect of carbon monoxide poisoning on hemorheological parameters in rats and the alterations in these parameters in response to three kinds of treatments.

This study aimed to investigate the short term effects of carbon monoxide (CO) poisoning and three kinds of poisoning treatments; namely room air, normobaric and hyperbaric oxygen on hemorheological parameters such as red blood cell (RBC) deformability, aggregation, blood and plasma viscosity. 43 Wistar rats were divided into 5 groups. Poisoning was induced by exposure to 4000 ppm CO (1 h). The poisoning protocol was followed by 3 types of treatments; room air, normobaric 100% oxygen and hyperbaric oxygen for 1 h. RBC deformability and aggregation were determined using an ektacytometer (LORCA) and a cone-plate rotational viscometer was used for the viscosity measurements. RBC deformability of CO poisoned rats were found to be elevated and the treatments applied, caused decrement of this parameter. A no significant increment tendency was found in erythrocyte aggregation after CO exposure. Although room air and hyperbaric oxygen treatments caused further significant elevations in the amplitude of aggregation, normobaric oxygen therapy induced decrement in this parameter towards control levels. No significant alterations were observed in viscosity values among the groups. The results of this study demonstrate normobaric oxygen therapy as a better choice of treatment after CO poisoning in hemorheological point of view.

The Effects of Electromagnetic Fields Generated from 1800 MHz Cell Phones on Erythrocyte Rheological Parameters and Zinc Level in Rats

OBJECTIVE The aim of this study was to investigate the effects of the electromagnetic field generated from the 1800 MHz radiofrequency radiation (EF) on erythrocyte rheological parameters and erythrocyte zinc levels. MATERIAL AND METHODS Twenty-four male Wistar Albino rats were randomly grouped as follows: 1) two control groups and 2) study groups: i) Group A: EF exposed group (2.5 h/day for 30 days, the phone on stand-by), and ii) Group B: EF exposed group (2.5 min/day for 30 days, the phone ringing in silent mode). At the end of the experimental period erythrocyte rheological parameters such as erythrocyte deformability and aggregation were determined by an ectacytometer. Erythrocyte zinc level, which affects hemorheological parameters, was also measured by atomic absorption spectrophotometer. RESULTS Erythrocyte deformability was decreased in both study groups but the decrease in group A was not statistically significant. Exposure to EF did not have any significant effect on erythrocyte aggregation. On the other hand, erythrocyte zinc level was significantly reduced in both study groups. CONCLUSION Exposure to EF may have decreased tissue oxygenation due to reduced erythrocyte deformability. Decrease in erythrocyte zinc level may have caused the impairment in erythrocyte deformability.

The effects of in vivo and ex vivo various degrees of cold exposure on erythrocyte deformability and aggregation.

Summary Background This study aimed to investigate alterations in hemorheology by cold exposure, in vivo and ex vivo, and to determine their relationship to oxidative stress. Material/Methods Rats were divided into 2 in vivo and ex vivo cold exposure groups. The in vivo group was further divided into control (AR), AC (4°C, 2 hours) and ALTC (4°C, 6 hours) subgroups; and the ex vivo group was divided into control (BR) and BC (4°C, 2 hours) subgroups. Blood samples were used for the determination of erythrocyte deformability, aggregation, and oxidative stress parameters. Results Erythrocyte deformability and aggregation were not affected by 2-hour ex vivo cold exposure. While 2 hour in vivo cold exposure reduced erythrocyte deformability, it returned to normal after 6 hours, possibly due the compensation by acute neuroendocrine response. Six hours of cold exposure decreased aggregation index, and might be an adaptive mechanism allowing the continuation of circulation. Aggregation of ex vivo groups was lower compared to in vivo groups. Cold exposure at various temperatures did not cause alterations in plasma total oxidant antioxidant status and oxidative stress index (TOS, TAS, OSI) when considered together. Conclusions Results of this study indicate that the alterations observed in hemorheological parameters due to cold exposure are far from being explained by the oxidative stress parameters determined herein.

Medico-legal Approach to Poisoning Cases in the First Decade of Life

Objective: Organ transplantation is one of the clinical scenarios involving ischemia and reperfusion process. Ischemia/reperfusion is the pivotal mechanism of organ injury during transplantation. Thus, ischemia/reperfusion (I/R) injury is a biphasic phenomenon that can damage the graft by inflammatory responses. The hypothalamic-pituitary-adrenal (HPA) axis is the main hormonal system that is activated under the influence of stress. Normal HPA axis activity leading to the release of glucocorticoids is essential for homeostasis and survival during stress. Cortisol, a key controller of stress response, is released by the HPA axis. The disrupted release of cortisol in response to inflammation has been shown in animal models. Nesfatin-1 is a peptide involved in the regulation of homeostasis and has anti-inflammatory as well as anti-ischemic properties. Therefore, we aimed to identify the effect of chronic peripheral nesfatin-1 application on the plasma level of cortisol in a rat model of intestinal I/R-based stress. Materials and Methods: Two-month-old 28 Wistar Albino male rats that weighed an average of 200–250 g were used and were randomly divided into the following four experimental groups (n=7): laparotomy, I/R, nesfatin-1+laparotomy, nesfatin-1+I/R. Blood samples were collected in tubes with EDTA. Plasma cortisol levels were analyzed by rat enzyme-linked immunosorbent assay (ELISA) kits. Results: Statistically significant decrease was found in the plasma level of cortisol in nesfatin-1+I/R group compared with I/R group (p=0.026) Conclusion: Nesfatin-1 application can inhibit anti-inflammatory responses under the early phase of intestinal I/R and support immune reactions by reducing plasma cortisol level. This effect of nesfatin-1 may also increase the rejection of grafts during transplantation period.