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1.
α-Lipoic acid (αLA), as an inductor of hydrogen peroxide (H2O2) and nitrogen oxide (NO) generation and modulator of thiol redox status, plays an important role in cell signalling pathways. The study was designed to observe the effect of αLA on inflammatory response through changes in H2O2 and NO levels as well as thiol redox status. Sixteen physically active males were randomly assigned to one of two groups: placebo or αLA (1,200 mg?d?1 for 10 days prior to exercise). The exercise trial involved a 90-min run at 65 % VO2max (0 % gradient) followed by 15-min eccentric phase at 65 % VO2max (?10 % gradient). Blood samples were collected before the exercise trial and then again 20 min, 24, and 48 h after. αLA significantly elevated H2O2 but reduced NO generation before or after exercise. Thiol redox status (GSHtotal-2GSSG/GSSG) increased by >50 % after αLA and exercise (ANOVA, P?<?0.05) and correlated with changes in cytokines interleukin-6 (IL-6) (r?=??0.478, P?<?0.05) and IL-10 (r?=??0.455, P?<?0.05). This was caused by strong effect of αLA on GSSG concentration. αLA elevated IL-6 and IL-10 levels at 20 min after exercise and decreased in interleukin-1β and tumor necrosis factor α before and after exercise. This enhanced the regeneration of injured muscles. Creatine kinase activity tended to lower values after αLA intake. The study suggests that the combination of intense exercise with α-lipoic acid intake might be useful to improve the skeletal muscle regeneration through changes in inflammatory response which are associated with H2O2 and NO generation as well as thiol redox status.  相似文献   

2.
This study investigated water holding capacity (WHC), water distribution, and protein denaturation of pork loin chops (longissimus lumborum) packaged in polyethylene bags throughout display at 4?±?1 °C for up to 1, 3, 5, 7 and 9 days. The drip loss of pork eventually increased following a decrease during the first 5 days of storage. Nuclear magnetic resonance (NMR) analysis revealed an increase in population of immobilized water P22 from day 1 to day 5, meanwhile a sharp decrease after 9 days was noticed. However, an opposite trend was observed for the population of free water P23. Correlation analysis indicated that myofibrillar protein solubility was negatively correlated with drip loss (p?<?0.05), whereas sarcoplasmic protein measurement were not related to drip loss (p?>?0.05). Furthermore, the content of α-helices increased during the first 5 days of storage (p?<?0.05), which suggested increased WHC during the earlier period of postmortem storage. During the subsequent postmortem storage, the content of α-helices decreased significantly (p?<?0.05), while the β-sheets and β-turns increased. The maximum temperatures (Tmax) of three endothermic peaks were found to be 53.6 °C, 65.2 °C, and 77.6 °C at 1 day postmortem. A significant decrease were observed for Tmax peakI,Tmax peakII,Tmax peakIII at 9 d when compared to 1 d postmortem (p?<?0.05), suggesting loss of thermal stability and protein denaturation.  相似文献   

3.
This study was performed to examine whether changes in subcutaneous adipose tissue (SCAT) metabolism indices after weight loss were related to the magnitude of weight regain. Nine men and ten premenopausal women whose body mass index ranged from 30 to 42 kg/m2, 35–48 years old, were studied before and after a 15-week weight loss program, as well as at a 17–22-month follow-up period. Although body composition was evaluated at all study periods, abdominal and femoral SCAT-lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) activities, and α2- and β-adrenoceptors (ARs) were measured before and after weight loss, exclusively. Although the SCAT-LPL activity did not change after weight loss in men, it tended to decrease in the femoral depot of women (p?=?0.06). SCAT-HSL activity remained unchanged after weight reduction in men, while the post-weight loss lipase activity tended to be higher in both regions of women (p?=?0.06). Although the post-weight loss number of β-ARs was higher irrespective of the fat depot (0.001?<?p?<?0.05), the number of α2-ARs was increased in the femoral (p?<?0.05), but not in the abdominal SCAT (p?=?0.08) after weight reduction, in men. Neither the α2- nor the β-AR density changed after weight reduction, in women. Abdominal SCAT-LPL activity after weight reduction was negatively related to weight regain indices, in women (?0.65?<?Rhô?<??0.75; 0.01?<?p?<?0.05). Both the post-weight loss abdominal SCAT α2-AR density and the α2-/β-AR balance were positively associated with weight regain indices, in men (0.69?<?Rhô?<?0.88; 0.01?<?p?<?0.05). These results suggest that selected SCAT metabolism indices could predict failure to weight loss maintenance, in both genders.  相似文献   

4.
The Caulobacter crescentus (NA1000) xynB5 gene (CCNA_03149) encodes a predicted β-glucosidase-β-xylosidase enzyme that was amplified by polymerase chain reaction; the product was cloned into the blunt ends of the pJet1.2 plasmid. Analysis of the protein sequence indicated the presence of conserved glycosyl hydrolase 3 (GH3), β-glucosidase-related glycosidase (BglX) and fibronectin type III-like domains. After verifying its identity by DNA sequencing, the xynB5 gene was linked to an amino-terminal His-tag using the pTrcHisA vector. A recombinant protein (95 kDa) was successfully overexpressed from the xynB5 gene in E. coli Top 10 and purified using pre-packed nickel-Sepharose columns. The purified protein (BglX-V-Ara) demonstrated multifunctional activities in the presence of different substrates for β-glucosidase (pNPG: p-nitrophenyl-β-D-glucoside) β-xylosidase (pNPX: p-nitrophenyl-β-D-xyloside) and α-arabinosidase (pNPA: p-nitrophenyl-α-L-arabinosidase). BglX-V-Ara presented an optimal pH of 6 for all substrates and optimal temperature of 50 °C for β-glucosidase and α-l-arabinosidase and 60 °C for β-xylosidase. BglX-V-Ara predominantly presented β-glucosidase activity, with the highest affinity for its substrate and catalytic efficiency (Km 0.24 ± 0.0005 mM, Vmax 0.041 ± 0.002 µmol min?1 mg?1 and Kcat/Km 0.27 mM?1 s?1), followed by β-xylosidase (Km 0.64 ± 0.032 mM, Vmax 0.055 ± 0.002 µmol min?1 mg?1 and Kcat/Km 0.14 mM?1s?1) and finally α-l-arabinosidase (Km 1.45 ± 0.05 mM, Vmax 0.091 ± 0.0004 µmol min?1 mg?1 and Kcat/Km 0.1 mM?1 s?1). To date, this is the first report to demonstrate the characterization of a GH3-BglX family member in C. crescentus that may have applications in biotechnological processes (i.e., the simultaneous saccharification process) because the multifunctional enzyme could play an important role in bacterial hemicellulose degradation.  相似文献   

5.
The effects of 3-week exercise training on the functions of peritoneal macrophages from BALB/c mice were investigated. Lipopolysaccharide (LPS)-stimulated nitric oxide (NO) and proinflammatory cytokine production in macrophages from trained mice was markedly higher than those from control mice. Meanwhile, exercise training decreased the steady state level of β2-adrenergic receptor (β2AR) mRNA in macrophages. Overexpression of β2AR in the macrophage cell line RAW264 by transfecting with β2AR cDNA suppressed NO synthase (NOS) II expression but dose not influenced proinflammatory cytokine expression. When expression of transfected β2AR in RAWar cells was downregulated by a tetracycline repressor-regulated mammalian expression system, NOS II mRNA expression was significantly increased; this suggested that the changes in the β2AR expression level in macrophages associated with exercise training play a role in the regulation of NO production following LPS stimulation. These findings indicate that exercise training improves macrophage innate immune function in a β2AR-dependent and -independent manner.  相似文献   

6.
The aim of this study was to assess the oxidative stress status in rheumatoid arthritis (RA) by measuring markers of free radical production, systemic activity of disease, and levels of antioxidant. 52 RA patients and 30 healthy controls were included in the study, and clinical examination and investigations were performed and disease activity was assessed. Peripheral blood samples were used for all the assays. We assessed the markers of oxidative stress, including plasma levels of index of lipid peroxidation-thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H2O2), superoxide anion radical (O2 ?), nitric oxide (NO), and superoxide dismutase activity (SOD), catalase activity (CAT) and glutathione levels in erythrocytes. In the RA group, levels of H2O2, O2 ?, and TBARS were significantly higher than in controls (4.08 ± 0.31 vs. 2.39 ± 0.13 nmol/l, p < 0.01; 8.90 ± 1.28 vs. 3.04 ± 0.38 nmol/l, p < 0.01, 3.65 ± 0.55 vs. 1.06 ± 0.17 μmol/l, p < 0.01). RA patients had significantly increased SOD activity compared with healthy controls (2,918.24 ± 477.14 vs. 643.46 ± 200.63UgHbx103, p < 0.001). Patients had significantly higher levels of pro-oxidants (O2 ?, H2O2, and TBARS) compared to controls, despite significantly higher levels of SOD. Significant differences were also observed in serum levels of NO in patients with high-diseases activity. Our findings support an association between oxidative/nitrosative stress and RA. Stronger response in samples with higher diseases activity suggests that oxidative/nitrosative stress markers may be useful in evaluating the progression of RA as well as in elucidating the mechanisms of disease pathogenesis.  相似文献   

7.
The levels of blood lipid peroxidation, glutathione peroxidase, reduced glutathione, and vitamin C were used to follow the level of oxidative damage caused by 2.45 GHz electromagnetic radiation in rats. The possible protective effects of selenium and L-carnitine were also tested and compared to untreated controls. Thirty male Wistar Albino rats were equally divided into five groups, namely Groups A1 and A2: controls and sham controls, respectively; Group B: EMR; Group C: EMR + selenium, Group D: EMR + L-carnitine. Groups B–D were exposed to 2.45 GHz electromagnetic radiation during 60 min/day for 28 days. The lipid peroxidation levels in plasma and erythrocytes were significantly higher in group B than in groups A1 and A2 (p?<?0.05), although the reduced glutathione and glutathione peroxidase values were slightly lower in erythrocytes of group B compared to groups A1 and A2. The plasma lipid peroxidation level in group A2 was significantly lower than in group B (p?<?0.05). Erythrocyte reduced glutathione levels (p?<?0.01) in group B; erythrocyte glutathione peroxidase activity in group A2 (p?<?0.05), group B (p?<?0.001), and group C (p?<?0.05) were found to be lower than in group D. In conclusion, 2.45 GHz electromagnetic radiation caused oxidative stress in blood of rat. L-carnitine seems to have protective effects on the 2.45-GHz-induced blood toxicity by inhibiting free radical supporting antioxidant redox system although selenium has no effect on the investigated values.  相似文献   

8.
Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C3b receptor rosette rate (E-C3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn–soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p?<?0.05 or p?<?0.01), and EOF was higher (p?<?0.05 or p?<?0.01) in the high F groups II and III than that in the control group from 14 to 42 days of age. The E-C3bRR was significantly decreased (p?<?0.01) in the three high F groups, whereas the E-ICRR was markedly increased (p?<?0.01) in the high F groups II and III from 14 to 42 days of age. It was concluded that dietary F in the range of 800 to 1, 200 mg/kg could significantly cause anemia and impair the integrity of erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.  相似文献   

9.
Although iron is a first-line pro-oxidant that modulates clinical manifestations of various systemic diseases, including diabetes, the individual tissue damage generated by active oxidant insults has not been demonstrated in current animal models of diabetes. We tested the hypothesis that oxidative stress is involved in the severity of the tissues injury when iron supplementation is administered in a model of type 1 diabetes. Streptozotocin (Stz)-induced diabetic and non-diabetic Fischer rats were maintained with or without a treatment consisting of iron dextran ip at 0.1 mL day?1 doses administered for 4 days at intervals of 5 days. After 3 weeks, an extensive increase (p < 0.001) in the production of reactive oxygen species (ROS) in neutrophils of the diabetic animals on iron overload was observed. Histological analysis revealed that this treatment also resulted in higher (p < 0.05) tissue iron deposits, a higher (p < 0.001) number of inflammatory cells in the pancreas, and apparent cardiac fibrosis, as shown by an increase (p < 0.05) in type III collagen levels, which result in dysfunctional myocardial. Carbonyl protein modification, a marker of oxidative stress, was consistently higher (p < 0.01) in the tissues of the iron-treated rats with diabetes. Moreover, a significant positive correlation was found between ROS production and iron pancreas stores (r = 0.42, p < 0.04), iron heart stores (r = 0.54, p < 0.04), and change of the carbonyl protein content in pancreas (r = 0.49, p < 0.009), and heart (r = 0.48, p < 0.02). A negative correlation was still found between ROS production and total glutathione content in pancreas (r = ?0.50, p < 0.03) and heart (r = ?0.45, p < 0.04). In conclusion, our results suggest that amplified toxicity in pancreatic and cardiac tissues in rats with diabetes on iron overload might be attributed to increased oxidative stress.  相似文献   

10.
The major objective of this study was to improve the development rate of parthenogenetic porcine embryos. In this study, the anti-oxidative and anti-apoptotic effects of three antioxidants, β-mercaptoethanol (β-ME), α-tocopherol, and extracellular superoxide dismutase (EC-SOD), were examined on the development of parthenogenetic porcine embryos. The development rate of parthenogenetic porcine embryos to the blastocyst stage was 8.1% for control; 19.1%, 14.6%, and 5.0% for 1, 3, and 5 μM β-ME; 17.2% and 17.5% for 50 and 100 μM α-tocopherol and 12.0% and 4.0% for EC-SOD transgenic mouse embryonic fibroblast (Tg-MEF) and EC-SOD non-transgenic mouse embryonic fibroblast (NTg-MEF) conditioned medium at day 3, respectively. Here, β-ME, α-tocopherol, and EC-SOD Tg-MEF conditioned medium increased the development rate of parthenogenetic porcine embryos to the blastocyst stage (P?<?0.05). The average number of total cells and apoptotic cells at the blastocyst was analyzed at the optimal conditions of the three antioxidants. The three antioxidants increased the average number of total cells at the blastocyst, and they decreased apoptotic cells at the blastocyst as compared to control without supplementation (P?<?0.05). When the reactive oxygen species levels in two-cell embryos after 1 μM β-ME and 100 μM α-tocopherol treatment were examined, those were lower than control group (P?<?0.05). In conclusion, it was found that the three antioxidants, β-mercaptoethanol, α-tocopherol, and EC-SOD Tg-MEF, conditioned medium can play a role as a strong stimulator in the development of parthenogenetic porcine embryos.  相似文献   

11.
The aim of this study was to investigate whether the presence of endogenous estradiol alters the effects of a high-fat (HF) diet on activity/expression of the cardiac Na+/K+-ATPase, via PI3K/IRS and RhoA/ROCK signalling cascades in female rats. For this study, female Wistar rats (8 weeks old, 150–200 g) were fed a standard diet or a HF diet (balanced diet for laboratory rats enriched with 42% fat) for 10 weeks. The results show that rats fed a HF diet exhibited a decrease in phosphorylation of the α1 subunit of Na+/K+-ATPase by 30% (p < 0.05), expression of total α1 subunit of Na+/K+-ATPase by 31% (p < 0.05), and association of IRS1 with p85 subunit of PI3K by 42% (p < 0.05), while the levels of cardiac RhoA and ROCK2 were significantly increased by 84% (p < 0.01) and 62% (p < 0.05), respectively. Our results suggest that a HF diet alters cardiac Na+/K+-ATPase expression via molecular mechanisms involving RhoA/ROCK and IRS-1/PI3K signalling in female rats.  相似文献   

12.
13.
The contribution of soybean variety and coagulant type to the textural and rheological properties of soy protein isolate (SPI) tofu-type emulsion gels was studied. SPIs from eight soybean varieties were subjected to amino acid and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis, and results showed that the 11S fraction proteins (r?=?0.833, p?<?0.05) and the ratio of 11S to 7S (r =?0.920, p <?0.01) were positively correlated with the hardness of CaSO4-induced emulsion gels and glucono-δ-lactone (GDL)-induced gels, with the correlation coefficients of 0.827 (p <?0.05) and 0.893 (p <?0.01), respectively. In the case of microbial transglutaminase (MTGase), strong relations between the content of glutamate (r =?0.886, p?<?0.01) and lysine (r =?0.810, p <?0.05) and gel hardness were found. Rheological data demonstrated that CaSO4-induced emulsion gel was stiffer with high rigidity but gel induced by MTGase performed better elasticity. The findings of this study are of great importance to further understand the gelation mechanisms of different coagulants and provide useful information for the development of SPI-based filled tofu.  相似文献   

14.
Mechanisms for the onset of diabetes and the development of diabetic complications remain under extensive investigations. One of these mechanisms is abnormal homeostasis of metals, as either deficiency or excess of metals, can contribute to certain diabetic outcomes. Therefore, this paper will report the blood levels of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in subjects with type 1 diabetes (n?=?192, mean age 48.8 years, mean disease duration 20.6 years), type 2 diabetes (n?=?68, mean age 68.4 years, mean disease duration 10.2 years), and in control subjects (n?=?59, mean age 57.2 years), and discuss the results indicating their possible role in diabetes. The metal concentrations were measured by sector field inductively coupled plasma mass spectrometry after microwave-induced acid digestion of blood samples. The accuracy was checked using a blood-based certified reference material, and recoveries of all elements were in the range of 92–101 % of certified values. Type 1 diabetes was found to be associated with Cr (p?=?0.02), Mn (p?<?0.001), Ni (p?<?0.001), Pb (p?=?0.02), and Zn (p?<?0.001) deficiency, and type 2 diabetes with Cr (p?=?0.014), Mn (p?<?0.001), and Ni (p?<?0.001) deficiency. These deficiencies were appreciated also subdividing the understudied patients for gender and age groups. Furthermore, in type 1 diabetes, there was a positive correlation between Pb and age (p?<?0.001, ρ?=?0.400) and Pb and BMI (p?<?0.001, ρ?=?0.309), while a negative correlation between Fe and age (p?=?0.002, ρ?=??0.218). In type 2 diabetes, there was a negative correlation between Fe and age (p?=?0.017, ρ?=??0.294) and Fe and BMI (p?=?0.026, ρ?=??0.301). Thus, these elements may play a role in both forms of diabetes and combined mineral supplementations could have beneficial effects.  相似文献   

15.
Ligands of 18 kDa mitochondrial translocator protein (TSPO) differ in their cellular effects. We hypothesize that different TSPO ligands might exert different cellular responses. Therefore, following previous studies that showed different cellular responses to two specific TSPO ligands, PK 11195 and protoporphyrin IX, in human osteoblast-like cells in vitro, we now report the cellular response to another specific TSPO ligand, FGIN-1-27 (10?5 M) (MW 436 kDa), in order to characterize the effects of each TSPO ligand. We found in primary culture of the human osteoblast-like cells that cell numbers were decreased by an average of 30 % (p?<?0.001) following exposure to 10?5 M of FGIN-1-27 in comparison to vehicle controls. Cellular [18F]-FDG incorporation and ATP content were suppressed, by an average of 43 % (p?<?0.001) and 83 % (p?<?0.001), respectively. Mitochondrial mass and ΔΨm increased by an average of 26 % (p?<?0.01) and 425 % (p?<?0.0001) respectively. Lactate dehydrogenase activity was enhanced in culture media by 60 % (p?<?0.05), indicating overall cell death, while no increase in apoptotic levels was observed. Cellular proliferation, as determined by BrdU assay, was not affected. Synthesis of mRNA of TSPO, VDAC 1, and hexokinase 2 decreased in 0.3, 0.3 and 0.5 fold respectively, with accompanying decreases in protein expression of TSPO and Voltage Dependent Anion Channel 1 by 23 % (p?<?0.001) and 98 % (p?<?0.001), respectively, but without changes in hexokinase 2 protein expression. Thus it appears that 10?5 M FGIN-1-27 reduces cell viability, cell metabolism, and mitochondrial function. Previously we found similar effects of PK 11195 on mitochondrial function and cell metabolism and of protoporphyrin IX on cell death in primary osteoblast-like cells.  相似文献   

16.
We investigated the effect of acrolein, a byproduct of lipid oxidation, on the structure and gel properties of myofibrillar proteins (MPs) isolated from rabbit meat. As the acrolein concentration increased, the protein carbonyl compounds significantly accumulated (p?<?0.05), and the total sulfhydryl content was significantly lost (p?<?0.05). The results of circular dichroism spectra, surface hydrophobicity, UV absorption spectra and intrinsic fluorescence spectra evidenced that acrolein caused the disruption of α-helix structure, the exposure of hydrophobic sites and the unfolding of MPs. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis suggested that medium (0–1 mM) and high (5–10 mM) concentrations of acrolein could induce protein cross-linkage and protein aggregation, respectively. These structural changes could affect gelling properties of MPs involving gel strength and water holding capacity (WHC). The results of Raman spectroscopy indicated that moderate oxidative modification caused protein unfolding as well as the decline of α-helix structure and the increase of β-sheets structure in gels, thereby influencing the gel properties. Moderate oxidative modification (0–1 mM) improved gel strength and WHC, while excessive oxidative modification (5–10 mM) resulted in decreased gel properties.  相似文献   

17.
This study was planned to determine the effects of lycopene treatment on serum protein fractions in experimental diabetic rats. In order to induce diabetes in rats in the diabetes (D) and diabetes + lycopene (DL) groups, rats were given 45 mg/kg single-dose streptozotocin intraperitoneally. Lycopene (10 mg/kg/day dissolved in sunflower oil) was administered to the rats in the lycopene-only (L) and DL groups. Blood glucose levels and HbA1c% in DL group and diabetes group increased (p < 0.05) compared to control and L group. Total protein, albumin, α1, α2, and β globulin fractions of diabetic and DL groups were lower than control and L groups (p < 0.05). D group had lowest gamma (γ) globulin levels among other groups (p < 0.05). The γ globulin levels was slightly increased than diabetic groups (D and DL), but it was still lower than control and L groups (p < 0.05). The highest value of A/G ratio was observed in diabetic group. Similarly, the % level of A/G ratio of D group was higher than other groups. It was noted that the A/G ratio decreased and reached to control group levels after lycopene treatment.  相似文献   

18.
19.
To assess the possible function of glutamate in the interaction between the dorsomedial hypothalamic nucleus-perifornical area (DMH-PeF) and the A5 pontine region (A5), cardiovascular and respiratory changes were studied in response to electrical stimulation of the DMH-PeF (1 ms pulses, 30–50 μA given at 100 Hz for 5 s) before and after the microinjection of kynurenic acid (non-specific glutamate receptor antagonist; 50 nl, 5 nmol), MK-801 (NMDA receptor antagonist; 50 nl, 50 nmol), CNQX (non-NMDA receptor antagonist; 50 nl, 50 nmol) or MCPG (metabotropic glutamate receptor antagonist; 50 nl, 5 nmol) within the A5 region. DMH-PeF electrical stimulation elicited a pressor (p <?0.001) and tachycardic response (p <?0.001) which was accompanied by an inspiratory facilitation characterised by an increase in respiratory rate (p <?0.001) due to a decrease in expiratory time (p <?0.01). Kynurenic acid within the A5 region decreased the tachycardia (p <?0.001) and the intensity of the blood pressure response (p <?0.001) to DMH-PeF stimulation. After the microinjection of MK-801 and CNQX into the A5 region, the magnitude of the tachycardia and the pressor response were decreased (p <?0.05 and p <?0.01; p <?0.001 and p <?0.05, respectively). After MCPG microinjection into the A5 region, a decrease in the tachycardia (p <?0.001) with no changes in the pressor response was observed during DMH-PeF stimulation. The respiratory response elicited by DMH-PeF stimulation was not changed after the microinjection of kynurenic acid, MK-801, CNQX or MCPG within the A5 region. These results suggest that A5 region glutamate receptors play a role in the cardiovascular response elicited from the DMH-PeF. The possible mechanisms involved in these interactions are discussed.  相似文献   

20.
This study investigated whether wearing common white sportswear can reduce heat stress more than being semi-nude during exercise of different intensities performed under radiant heat and wind conditions, such as a hot summer day. After a 20-min rest period, eight male subjects performed three 20 min sessions of cycling exercise at a load intensity of 20 % or 50 % of their peak oxygen uptake (VO2peak) in a room maintained at a wet bulb globe temperature (WBGT) of 28.7?±?0.1 °C using two spot lights and a fan (0.8 m/s airflow). Subjects wore common white sportswear (WS) consisting of a long-sleeved shirt (45 % cotton and 55 % polyester) and short pants (100 % polyester), or only swimming pants (SP) under the semi-nude condition. The mean skin temperature \( \left(\overline{T} sk\right) \) was greater when subjects wore SP than WS under both the 20 % and 50 % exercise conditions. During the 50 % exercise, the rating of perceived exertion (RPE) and thermal sensation (TS), and the increases in esophageal temperature (ΔTes) and heart rate were significantly higher (P?<?0.001–0.05), or tended to be higher (P?<?0.07), in the WS than SP trials at the end of the third 20-min exercise session. The total sweat loss (m sw,tot) was also significantly higher in the WS than in the SP trials (P?<?0.05). However, during the 20 % exercise, the m sw,tot during exercise, and the ΔTes, RPE and TS at the end of the second and third sessions of exercise did not differ significant between conditions. The heat storage (S), calculated from the changes in the mean body temperature (0.9Tes + 0.1 \( \overline{T} sk \) ), was significantly lower in the WS trials than in the SP trials during the 20 min resting period before exercise session. However, S was similar between conditions during the 20 % exercise, but was greater in the WS than in the SP trials during 50 % exercise. These results suggest that, under conditions of radiant heat and wind at a WBGT greater than 28 °C, the heat stress associated with wearing common WS is similar to that of being semi-nude during light exercise, but was greater during moderate exercise, and the storage of body heat can be reduced by wearing WS during rest periods.  相似文献   

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