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

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. © Med Sci Monit

Hemorheological responses to progressive resistance exercise training in healthy young males

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. © Med Sci Monit

Vitamin e treatment enhances erythrocyte deformability in aged rats

The harmful effects of aging on blood rheology have been well known. These effects in the aging have been found to be associated with an increase in oxidative stress. The aim of this study was to seek whether treatment of vitamin E as a potent antioxidant could improve the age-related haemorheological abnormalities. For this purpose, male Wistar rats at the age of 3 and 24 months were used. The following parameters were evaluated: red blood cell (RBC) deformability, aggregation, plasma viscosity, vitamin E level, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI), and the following results were obtained. First, aging was associated with a decrease in RBC deformability and increase in RBC aggregation and plasma viscosity. Second, compared with the young group, while plasma TOS levels and OSI were found to be significantly increased in aged rats, there was no significant change in their plasma TAS level. Third, vitamin E administration produced significant improvement in RBC deformability and decrement in TOS and OSI values in aged rats with respect to young and aged control groups. We did not find any significant effect of vitamin E treatment on RBC aggregation in both young and aged rats and finally, we found a significantly lower plasma vitamin E level in aged rats than in young rats. In conclusion, these findings suggest that blood rheology impairs with age and vitamin E has ameliorating effects on age-induced haemorheological abnormalities especially in RBC deformability, probably by reducing the increased oxidative stress in old age

Contribution of heme oxygenase 2 to blood pressure regulation in response to swimming exercise and detraining in spontaneously hypertensive rats

Background: We aimed to determine the effects of exercise followed by detraining on systolic blood pressure (SBP), heme oxygenase 2 (HO-2) expression, and carboxyhemoglobin (COHb) concentration in spontaneously hypertensive rats (SHR) to explain the role of carbon monoxide (CO) in this process. Material/Methods: Animals were randomized into exercised and detrained groups. Corresponding sedentary rats were grouped as Time 1–2. Swimming of 60 min/5 days/week for 10 weeks was applied. Detraining rats discontinued training for an additional 5 weeks. Gene and protein expressions were determined by real-time PCR and immunohistochemistry. Results: Aorta HO-2 histological scores (HSCORE) of hypertensive rats were lower, while SBP was higher. Swimming caused enhancement of HO-2 immunostaining in aorta endothelium and adventitia of SHR. Exercise induced elevation of blood COHb index in SHR. Synchronous BP lowering effect of exercise was observed. HO-2 mRNA expression, HSCORE, and blood COHb index were unaltered during detraining, while SBP was still low in SHR. Conclusions: CO synthesized by HO-2 at least partly plays a role in SBP regulation in the SHR-and BP-lowering effect of exercise. Regular exercise with short-term pauses may be advised to both hypertensives and individuals who are at risk. © Med Sci Monit

Oxidative stress of crystalline lens in rat menopausal model

Purpose: To evaluate lenticular oxidative stress in rat menopausal models. Methods: Forty Wistar female albino rats were included in this study. A total of thirty rats underwent oophorectomy to generate a menopausal model. Ten rats that did not undergo oophorectomy formed the control group (Group 1). From the rats that underwent oophorectomy, 10 formed the menopause control group (Group 2), 10 were administered a daily injection of methylprednisolone until the end of the study (Group 3), and the remaining 10 rats were administered intraperitoneal streptozocin to induce diabetes mellitus (Group 4). Total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) measurements of the crystalline lenses were analyzed. Results: The mean OSI was the lowest in group 1 and highest in group 4. Nevertheless, the difference between the groups was not statistically significant in terms of OSI (p > 0.05). The mean TOS values were similar between the groups (p > 0.05), whereas the mean TAC of group 1 was significantly higher than that of the other groups (p < 0.001). Conclusions: Our results indicate that menopause may not promote cataract formation

Expression of URG4/URGCP, Cyclin D1, Bcl-2, and Bax genes in retinoic acid treated SH-SY5Y human neuroblastoma cells

Retinoic acid (RA) plays important roles in development, growth, and differentiation by regulating the expression of its target genes. The pro-apoptotic Bax gene may form channels through oligomerization in the mitochondrial membrane and facilitate the cytosolic release of cytochrome c. The anti-apoptotic Bcl-2 gene can inhibit this process. Up-regulated gene 4/Upregulator of cell proliferation (URG4/URGCP) is a novel gene located on 7p13. URG4/ URGCP also stimulates cyclin D1 (CCND1) mRNA expression, and RNAi-mediated URG4/URGCP silencing diminishes CCND1mRNA expression in HepG2 cells. In this study, the effects of RA treatment on URG4/URGCP, CCND1, Bcl-2 and Bax gene expression changes in undifferentiated and differentiated SHSY5Y neuroblastoma cells was analyzed. SHSY5Y cells were cultured in the appropriate conditions. To induce differentiation, the cells were treated with 10micromolar RA in the dark for 3-10 days. SHSY5Y cells possess small processes in an undifferentiated state, and after treatment with RA, the cells developed long neurites, resembling a neuronal phenotype. Total RNA was isolated with Tri-Reagent. Expression profiles of the target genes were determined by semi-quantitative RT-PCR. According to the results, Bcl-2 and CCND1 gene expression levels were increased, while URG4/URGCP and Bax gene expression was decreased in RA treated cells compared to the control cells. Our preliminary results suggest that RA may induce cell proliferation and escape apoptosis using a novel pathway by the URG4/URGCP gene. Further investigations are needed to clarifymore direct transcriptional targets of RA signaling and the interaction of RA pathways with other pro-regenerative signals

The renoprotective effects of mannitol and udenafil in renal ischemia-reperfusion injury model

Purpose: The aim of this study was to investigate and compare the effects of udenafil and mannitol in an experimental renal ischemia-reperfusion (I/R) injury model.Materials and Methods: A total of 64 female Wister Albino rats were used. Right nephrectomy was performed in all groups. In the control group; I/R injury was not performed. In the I/R group; left renal pedicle was clamped for 45 minutes and then underwent 60 minutes and 24 hours of reperfusion. In the mannitol group; 1 mL 20% mannitol was given intravenously 15 minutes before clamping. In the udenafil group; 10-mg/kg udenafil was given orally 1 hour before clamping. Creatinine (Cr), blood urea nitrogen (BUN), Cr clearance, malondialdehyde, neutrophil gelatinase associated lipocalin (NGAL), histological examination and DNA damage (Comet Assay method) levels were compared in tissue, serum and urine samples.Results: Udenafil had a better protective effect than mannitol according to biochemical parameters (Cr, BUN, Cr clearance, and NGAL levels) and histopathological findings when compared with the I/R group. In the Comet sampling analysis no significant difference was detected.Conclusions: Udenafil has a better renoprotective effect than mannitol against I/R injury and this effect supports more functional improvements. Further clinical trials are needed to demonstrate those effects and clinical utility of udenafil for that purpose in humans

Regulation of URG4/URGCP and PPARα gene expressions after retinoic acid treatment in neuroblastoma cells

Neuroblastoma (NB), originating from neural crest cells, is the most common extracranial tumor of childhood. Retinoic acid (RA) which is the biological active form of vitamin A regulates differentiation of NB cells, and RA derivatives have been used for NB treatment. PPARα (peroxisome proliferator-activated receptor) plays an important role in the oxidation of fatty acids, carcinogenesis, and differentiation. URG4/URGCP gene is a proto-oncogene and that overexpression of URG4/URGCP is associated with metastasis and tumor recurrence in osteosarcoma. It has been known that URG4/URGCP gene is an overexpressed gene in hepatocellular carcinoma and gastric cancers. This study aims to detect gene expression patterns of PPARα and URG4/URGCP genes in SH-SY5Y NB cell line after RA treatment. Expressions levels of PPARα and URG4/URGCP genes were analyzed after RA treatment for reducing differentiation in SH-SY5Y NB cell line. To induce differentiation, the cells were treated with 10 μM RA in the dark for 3-10 days. Gene expression of URG4/URGCP and PPARα genes were presented as the yield of polymerase chain reaction (PCR) products from target genes compared with the yield of PCR products from the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. SH-SY5Y cells possess small processes in an undifferentiated state, and after treatment with RA, the cells developed long neurites, resembling a neuronal phenotype. PPARα gene expression increased in RA-treated groups; URG4/URGCP gene expression decreased in SH-SY5Y cells after RA treatment compared with that in the control cells. NB cell differentiation might associate with PPARα and URG4/URGCP gene expression profile after RA treatment. © 2013 International Society of Oncology and BioMarkers (ISOBM)

Increased deformability of red blood cells is associated with a deletion polymorphism of the angiotensin-converting enzyme gene

Angiotensin-converting enzyme (ACE) plays important roles in the renin-angiotensin system. ACE converts angiotensin I to angiotensin II and also inactivates bradykinin, thereby modulating the vascular tone. A polymorphism of the ACE gene, located on chromosome 17, has been found in intron 16, and is characterized by the presence (insertion [I]) or absence (deletion [D]) of a 287-base-pair Alu repeat. Individuals with the D allele of the ACE gene have higher ACE levels and are at higher risk of cardiovascular events. We aimed to investigate the possible relationship between the I/D polymorphism of the ACE gene and hemorheological parameters, including red blood cell (RBC) deformability. The study was performed on 28 healthy young volunteers (13 women and 15 men, mean age 24 ± 2). The prevalence of the I and D alleles was 30.4% and 69.6%, respectively. The I/I genotype (II) was found in 21.4%, I/D genotype (ID) in 17.9%, and D/D genotype (DD) in 60.7% of the subjects tested. No significant relationship between ACE I/D polymorphism and RBC aggregation or whole blood and plasma viscosity was observed. In contrast, RBC deformability was significantly increased in the subjects with the DD genotype compared with the II (p < 0.05) or the ID (p < 0.01) genotype, and in the subjects with the D allele compared with the I allele (p < 0.01). We suggest that RBC deformability of individuals with the D allele, who have higher risk for cardiovascular pathologies, may have been increased by a compensatory mechanism. © 2006 Tohoku University Medical Press

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. Copyright © Informa UK Ltd