Expression of the inducible nitric oxide synthase (iNOS) in human leukocytes: responses to running exercise

Supplementation of L-Arginine, L-Glutamine, Vitamin C, Vitamin E, Folic Acid, and Green Tea Extract Enhances Serum Nitric Oxide Content and Antifatigue Activity in Mice

It has been reported that abundant nitric oxide content in endothelial cells can increase exercise performance. The purpose of this study was to evaluate the potential beneficial effects of a combined extract comprising L-arginine, L-glutamine, vitamin C, vitamin E, folic acid, and green tea extract (LVFG) on nitric oxide content to decrease exercise fatigue. Male ICR (Institute of Cancer Research) mice were randomly divided into 4 groups and orally administered LVFG for 4 weeks. The 4-week LVFG supplementation significantly increased serum nitric oxide content in the LVFG-1X and LVFG-2X groups. Antifatigue activity and exercise performance were evaluated using forelimb grip strength, exhaustive swimming test, and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after an acute swimming exercise. LVFG supplementation dose-dependently improved exercise performance and nitric oxide content, and it dose-dependently decreased serum ammonia and CK activity after exhaustive swimming test. LVFG's antifatigue properties appear to manifest by preserving energy storage (as blood glucose) and increasing nitric oxide content. Taken together, our results show that LVFG could have the potential for alleviating physical fatigue due to its pharmacological effect of increasing serum nitric oxide content.

Inducible nitric oxide synthase inhibitor, 1400W, mitigates DFP-induced long-term neurotoxicity in the rat model

Chemical nerve agents (CNA) are increasingly becoming a threat to both civilians and military personnel. CNA-induced acute effects on the nervous system have been known for some time and the long-term consequences are beginning to emerge. In this study, we used diisopropylfluorophosphate (DFP), a seizurogenic CNA to investigate the long-term impact of its acute exposure on the brain and its mitigation by an inducible nitric oxide synthase (iNOS) inhibitor, 1400W as a neuroprotectant in the rat model. Several experimental studies have demonstrated that DFP-induced seizures and/or status epilepticus (SE) causes permanent brain injury, even after the countermeasure medication (atropine, oxime, and diazepam). In the present study, DFP-induced SE caused a significant increase in iNOS and 3-nitrotyrosine (3-NT) at 24 h, 48 h, 7d, and persisted for a long-term (12 weeks post-exposure), which led to the hypothesis that iNOS is a potential therapeutic target in DFP-induced brain injury. To test the hypothesis, we administered 1400W (20 mg/kg, i.m.) or the vehicle twice daily for the first three days of post-exposure. 1400W significantly reduced DFP-induced iNOS and 3-NT upregulation in the hippocampus and piriform cortex, and the serum nitrite levels at 24 h post-exposure. 1400W also prevented DFP-induced mortality in <24 h. The brain immunohistochemistry (IHC) at 7d post-exposure revealed a significant reduction in gliosis and neurodegeneration (NeuN+ FJB positive cells) in the 1400W-treated group. 1400W, in contrast to the vehicle, caused a significant reduction in the epileptiform spiking and spontaneous recurrent seizures (SRS) during 12 weeks of continuous video-EEG study. IHC of brain sections from the same animals revealed a significant reduction in reactive gliosis (both microgliosis and astrogliosis) and neurodegeneration across various brain regions in the 1400W-treated group when compared to the vehicle-treated group. A multiplex assay from hippocampal lysates at 6 weeks post-exposure showed a significant increase in several key pro-inflammatory cytokines/chemokines such as IL-1α, TNFα, IL-1β, IL-2, IL-6, IL-12, IL-17a, MCP-1, LIX, and Eotaxin, and a growth factor, VEGF in the vehicle-treated animals. 1400W significantly suppressed IL-1α, TNFα, IL-2, IL-12, and MCP-1 levels. It also suppressed DFP-induced serum nitrite levels at 6 weeks post-exposure. In the Morris water maze, the vehicle-treated animals spent significantly less time in the target quadrant in a probe trial at 9d post-exposure compared to their time spent in the same quadrant 11 days previously (i.e., 2 days prior to DFP exposure). Such a difference was not observed in the 1400W and control groups. However, learning and short-term memory were unaffected when tested at 10-16d and 28-34d post-exposure. Accelerated rotarod, horizontal bar test, and the forced swim test revealed no significant changes between groups. Overall, the findings from this study suggest that 1400W may be considered as a potential therapeutic agent as a follow-on therapy for CNA exposure, after controlling the acute symptoms, to prevent mortality and some of the long-term neurotoxicity parameters such as epileptiform spiking, SRS, neurodegeneration, reactive gliosis in some brain regions, and certain key proinflammatory cytokines and chemokine.

Swimming versus running: effects on exhaled breath condensate pro-oxidants and pH

PURPOSE

The respiratory redox-state of swimmers can be affected by chronic exposures to chlorinated pools, and the effects of different exercises on it are unknown. Our aim was to compare two exercises performed at high-intensity and under habitual environmental conditions (swimming indoor vs. running outdoor) on the production of pro-oxidants (hydrogen peroxide and nitrite) and pH in exhaled breath condensate (EBC) and spirometry parameters in competitive swimmers chronically exposed to chlorinated pools.

METHODS

Seventeen men and women (mean age ± SD = 21 ± 2 years) swam 3.5 km in an indoor pool treated with Cl_2, and after 2-weeks, they ran 10 km outdoors. The pH_EBC, [H₂O₂]_EBC, [NO₂^-]_EBC, [NO₂^-]_EBC/[NO₂^-]_Plasma and spirometry parameters were analyzed pre-exercise and 20 min and 24 h after exercise ended.

RESULTS

Two mixed models were applied to compare EBC parameters between swimming and running. Lower levels of [H₂O₂]_EBC and [NO₂^-]_EBC (p = 0.008 and p = 0.018, respectively) were found 24-h post-swimming, and the same trend was observed for [NO₂^-]_EBC/[NO₂^-]_Plasma (p = 0.062). Correlations were found in both exercises between pre-exercise levels of pH_EBC, [H₂O₂]_EBC, [NO₂^-]_EBC, and [NO₂^-]_EBC/[NO₂^-]_Plasma and their changes (Δ) after 24-h as well as between [H₂O₂]_EBC and [NO₂^-]_EBC for basal levels and for changes after 24 h. A relationship was also found for running exercise between pulmonary ventilation and changes after 24 h in [H₂O₂]_EBC. Spirometry data were unaffected in both types of exercise.

CONCLUSION

In competitive swimmers, at 24-h acute post-exercise follow-up, swimming decreased and running increased pro-oxidant biomarkers of pulmonary origin, without changes in lung function.

Acute and Chronic Effects of Endurance Running on Inflammatory Markers: A Systematic Review

In order to understand the effect of endurance running on inflammation, it is necessary to quantify the extent to which acute and chronic running affects inflammatory mediators. The aim of this study was to summarize the literature on the effects of endurance running on inflammation mediators. Electronic searches were conducted on PubMED and Science Direct with no limits of date and language of publication. Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) investigating the acute and chronic effects of running on inflammation markers in runners were reviewed by two researchers for eligibility. The modified Downs and Black checklist for the assesssments of the methodological quality of studies was subsequently used. Fifty-one studies were finally included. There were no studies with elite athletes. Only two studies were chronic interventions. Results revealed that acute and chronic endurance running may affect anti- and pro-inflammatory markers but methodological differences between studies do not allow comparisons or generalization of the results. The information provided in this systematic review would help practitioners for better designing further studies while providing reference values for a better understanding of inflammatory responses after different running events. Further longitudinal studies are needed to identify the influence of training load parameters on inflammatory markers in runners of different levels and training background.

Effects of Exercise on Gene Expression of Inflammatory Markers in Human Peripheral Blood Cells: A Systematic Review

Regular physical activity seems to be one of the most important contributors to prevent disease and promote health. Being physically active reduces the risk of developing chronic diseases such as cardiovascular disease, diabetes, and some types of cancers. The molecular mechanisms are however not fully elucidated. Depending on duration and intensity, exercise will cause disruption of muscle fibers triggering a temporary inflammatory response. This response may not only involve the muscle tissue, but also peripheral tissues such as white blood cells, which are important components of the immune system. The immune system plays a vital role in the development of atherosclerosis, thereby making white blood cells relevant to study when looking at molecular mechanisms induced by physical activity. In this review, we summarize the existing literature on exercise and gene expression in human white blood cells, and discuss these results in relation to inflammation and atherosclerosis.

Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running--a pilot investigation

Background

Prolonged exercise, such as marathon running, has been associated with an increase in respiratory mucosal inflammation. The aim of this pilot study was to examine the effects of Montmorency cherry juice on markers of stress, immunity and inflammation following a Marathon.

Methods

Twenty recreational Marathon runners consumed either cherry juice (CJ) or placebo (PL) before and after a Marathon race. Markers of mucosal immunity secretory immunoglobulin A (sIgA), immunoglobulin G (IgG), salivary cortisol, inflammation (CRP) and self-reported incidence and severity of upper respiratory tract symptoms (URTS) were measured before and following the race.

Results

All variables except secretory IgA and IgG concentrations in saliva showed a significant time effect (P <0.01). Serum CRP showed a significant interaction and treatment effect (P < 0.01). The CRP increase at 24 and 48 h post-Marathon was lower (P < 0.01) in the CJ group compared to PL group. Mucosal immunity and salivary cortisol showed no interaction effect or treatment effect. The incidence and severity of URTS was significantly greater than baseline at 24 h and 48 h following the race in the PL group and was also greater than the CJ group (P < 0.05). No URTS were reported in the CJ group whereas 50 % of runners in the PL group reported URTS at 24 h and 48 h post-Marathon.

Conclusions

This is the first study that provides encouraging evidence of the potential role of Montmorency cherries in reducing the development of URTS post-Marathon possibly caused by exercise-induced hyperventilation trauma, and/or other infectious and non-infectious factors.

Circulating cell-free DNA: an up-coming molecular marker in exercise physiology

The phenomenon of circulating cell-free DNA (cfDNA) concentrations is of importance for many biomedical disciplines including the field of exercise physiology. Increases of cfDNA due to exercise are described to be a potential hallmark for the overtraining syndrome and might be related to, or trigger adaptations of, immune function induced by strenuous exercise. At the same time, exercise provides a practicable model for studying the phenomenon of cfDNA that is described to be of pathophysiological relevance for different topics in clinical medicine like autoimmune diseases and cancer. In this review, we are summarizing the current knowledge of exercise-based acute and chronic alterations in cfDNA levels and their physiological significance. The effects of acute exercise on cfDNA concentrations have been investigated in resistance exercises and in continuous, stepwise and interval endurance exercises of different durations. cfDNA concentrations peaked immediately after acute exercise and showed a rapid return to baseline levels. Typical markers of skeletal muscle damage (creatine kinase, uric acid, C-reactive protein) show delayed kinetics compared with the cfDNA peak response. Exercise parameters such as intensity, duration or average energy expenditure do not explain the extent of increasing cfDNA concentrations after strenuous exercise. This could be due to complex processes inside the human organism during and after physical activity. Therefore, we hypothesize composite effects of different physiological stress parameters that come along with exercise to be responsible for increasing cfDNA concentrations. We suggest that due to acute stress, cfDNA levels increase rapidly by a spontaneous active or passive release mechanism that is not yet known. As a result of the rapid and parallel increase of cfDNA and lactate in an incremental treadmill test leading to exhaustion within 15-20 minutes, it is unlikely that cfDNA is released into the plasma by typical necrosis or apoptosis of cells in acute exercise settings. Recently, rapid DNA release mechanisms of activated immune-competent cells like NETosis (pathogen-induced cell death including the release of neutrophil extracellular traps [NETs]) have been discovered. cfDNA accumulations might comprise a similar kind of cell death including trap formation or an active release of cfDNA. Just like chronic diseases, chronic high-intensity resistance training protocols induced persistent increases of cfDNA levels. Chronic, strenuous exercise protocols, either long-duration endurance exercise or regular high-intensity workouts, induce chronic inflammation that might lead to a slow, constant release of DNA. This could be due to mechanisms of cell death like apoptosis or necrosis. Yet, it has neither been implicated nor proven sufficiently whether cfDNA can serve as a marker for overtraining. The relevance of cfDNA with regard to overtraining status, performance level, and the degree of physical exhaustion still remains unclear. Longitudinal studies are required that take into account standardized and controlled exercise, serial blood sampling, and large and homogeneous cohorts of different athletic achievement. Furthermore, it is important to establish standardized laboratory procedures for the measurement of genomic cfDNA concentrations by quantitative real-time polymerase chain reaction (PCR). We introduce a new hypothesis based on acute exercise and chronic exposure to stress, and rapid active and passive chronic release of cfDNA fragments into the circulation.

NO signaling in exercise training-induced anti-apoptotic effects in human neutrophils

Short-lived neutrophils play a predominant role in innate immunity, the effects of exercise training on neutrophil survival is unclear. In this study, we investigated the underlying mechanisms of training effects on human neutrophil apoptosis. Healthy male subjects were trained on a cycling ergometer for 8 weeks and followed by 4 weeks of detraining. Blood neutrophils were collected before exercise, after training, and after detraining. Comparing with pre-exercise specimens, neutrophils collected after training showed reduced apoptosis rate, which partially returned after detraining. Various intracellular proteins, including iNOS, Mcl-1, A1, Grp78, and IL-8, were upregulated by training, and they remained high after detraining. Upregulated iNOS was closely correlated with these anti-apoptotic molecules in neutrophils. Furthermore, the possible mechanism by which iNOS suppressed apoptosis was explored. Neutrophil apoptosis was accelerated by blocking and retarded by stimulating the endogenous iNOS activity. As an anti-apoptosis mediator of NO signaling, the Mcl-1 level dropped by depletion of the major NO downstream molecule cGMP and such loss of Mcl-1 was avoidable when supplying exogenous NO. Upon activation of NO-cGMP signaling, neutrophils held increased Mcl-1 expression and delayed apoptosis. Collectively, our results suggested that exercise training may retard neutrophil apoptosis by upregulating the iNOS-NO-cGMP-Mcl-1 pathway.

Eccentric training impairs NF-kappaB activation and over-expression of inflammation-related genes induced by acute eccentric exercise in the elderly

The present study was aimed to investigate in elderly humans changes in NF-kappaB activation and in the expression of the inflammation-related genes inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) induced in peripheral blood mononuclear cells (PBMC) by acute eccentric exercise and by submaximal eccentric training. Eleven subjects, aged 66-75 years, carried out 2 bouts of eccentric exercise separated by 8 weeks of training. Following the first bout, NF-kappaB activation, and protein level of p50/p65 subunits, phospho-IkappaBalpha and phospho-IKKalpha increased, while IkappaBalpha protein level was significantly reduced. This was accompanied by a significant increase in iNOS, COX-2 and IL-6 mRNA protein level and protein content. Changes were significantly attenuated following the second exercise bout. In conclusion, acute eccentric exercise increases NF-kappaB activation and the expression of several inflammation-related genes in PBMC from elderly individuals. Regular eccentric training might be an effective method of preventing undesirable inflammatory responses induced by eccentric exercise.

Scuba diving enhances endogenous antioxidant defenses in lymphocytes and neutrophils

The aim was to study the effects of a scuba diving session on the lymphocyte antioxidant system, NO synthesis, the capability to produce reactive oxygen species and the antioxidant response in neutrophils. For that purpose seven male divers performed an immersion at a depth of 40 m for 25 min. The same parameters were measured after an hyperbaric oxygen (HBO) treatment at resting conditions in a hyperbaric chamber. Lymphocyte H2O2 production rose after diving and after HBO treatment. Glutathione peroxidase (GPx) and catalase activities increased after diving in lymphocytes, while after HBO exposure only increased GPx activity. Lymphocyte HO-1 mRNA expression increased after diving and after HBO exposure, while iNOS levels and nitrite levels significantly increased after diving. The hyperoxia associated to scuba diving leads to a condition of oxidative stress with increased lymphocyte H2O2 production, HO-1 expression, NO synthesis and antioxidant enzyme adaptations in order to avoid oxidative damage.

Exhaled nitric oxide in single and repetitive prolonged exercise

This study was performed to determine the influence of single and repetitive exercise on nitric oxide (NO) concentration in the lung. Exhaled NO concentration (FE(NO)) was measured during a constant-flow exhalation manoeuvre (170 ml x s(-1), against a 10 cmH2O resistance) in healthy individuals (a) during and after a 100-min square-wave exercise of between 25 and 60% of maximal power output (n = 18) and (b) before and after five successive prolonged exercises (90-120 min, 75-85% of maximal heart rate) separated by 48 or 24 h (n = 8). The FE(NO0.170) was decreased during and after the 100-min exercise test (mean +/- s(x): 58.5 +/- 3.7% and 76.7 +/- 5.2% of resting value at 90 min of exercise and 15 min post-exercise, respectively; P < 0.05). The five successive exercise sessions induced a similar post-exercise FE(NO0.170) decrement (73.1 +/- 2.9% of resting value 15 min post-exercise), while basal FE(NO0.170) values were not different between the five sessions (P > 0.05). These results suggest that prolonged exercise induces a reduction in NO concentration within the lung that lasts for several minutes after the end of exercise. However, repetitive exercises (at least every 24 h) allow complete NO recovery from one session to another. The implication of such a decrease in NO availability within the lung remains to be clarified.

Exercise-induced oxidative stress:myths, realities and physiological relevance

Although assays for the most popular markers of exercise-induced oxidative stress may experience methodological flaws, there is sufficient credible evidence to suggest that exercise is accompanied by an increased generation of free radicals, resulting in a measurable degree of oxidative modifications to various molecules. However, the mechanisms responsible are unclear. A common assumption that increased mitochondrial oxygen consumption leads per se to increased reactive oxygen species (ROS) production is not supported by in vitro and in vivo data. The specific contributions of other systems (xanthine oxidase, inflammation, haem protein auto-oxidation) are poorly characterised. It has been demonstrated that ROS have the capacity to contribute to the development of muscle fatigue in situ, but there is still a lack of convincing direct evidence that ROS impair exercise performance in vivo in humans. It remains unclear whether exercise-induced oxidative modifications have little significance, induce harmful oxidative damage, or are an integral part of redox regulation. It is clear that ROS play important roles in numerous physiological processes at rest; however, the detailed physiological functions of ROS in exercise remain to be elucidated.

Role of fatty acids in the transition from anaerobic to aerobic metabolism in skeletal muscle during exercise

In moderate physical exercise, the transition from predominantly anaerobic towards predominantly aerobic metabolism is a key step to improve performance. Increase in the supply of oxygen and nutrients, such as free fatty acids (FFA) and glucose, which accompanies high blood flow, is required for this transition. The mechanisms involved in the vasodilation in skeletal muscle during physical activity are not completely known yet. In this article, we postulate a role of FFA and heat production in this process. The presence of uncoupling protein-2 and -3 (UCP-2 and -3) in skeletal muscle, whose activity is dependent on FFA, suggests that these metabolites can act as mitochondrial uncouplers in this tissue. Evidence indicates however that UCPs act as uncouplers only when coenzyme Q is predominantly in the reduced state (i.e. under nonphosphorylation conditions or state 4 respiration) as is observed in resting muscles and in the beginning of physical activity (predominantly anaerobic metabolism). The increase in the lipolytic activity in adipose tissue in the beginning of physical activity results in elevated plasma FFA levels. The FFA can then act on the UCPs, increasing the local heat production. We propose that this calorigenic effect of FFA is important to activate nitric oxide synthase, resulting in nitric oxide production and consequent vasodilation. Therefore, FFA would be important mediators for the changes that occur in muscle metabolism during prolonged physical activity, ensuring the appropriate supply of oxygen and nutrients by increasing blood flow at the beginning of exercise in the contracting skeletal muscles.

Effect of moderate-intensity exercise, whole-body periodic acceleration, and passive cycling on nitric oxide release into circulation

STUDY OBJECTIVE

To determine if a 3-min bout of moderately intensive supine bicycle exercise, whole-body periodic acceleration (pGz), and passive motorized cycling cause nitric oxide (NO) release into the circulation, as detected by dicrotic notch descent on the diastolic limb of a finger pulse wave.

PARTICIPANTS

Fourteen healthy adults underwent two levels of supine bicycle ergometry that caused heart rate to rise to 56% (light moderate exercise) and 67% (heavy moderate exercise) of maximum predicted heart rate, and a single bout of pGz. Several months later, 9 of the 14 subjects underwent passive motorized cycling.

METHODS

The ECG and finger pulse wave were recorded. The dicrotic notch position was computed from the amplitude of the digital pulse wave (a) divided by the height of the dicrotic notch above the end-diastolic level (b) and designated the a/b ratio. Increase of the a/b ratio due to dicrotic notch descent reflects the vasodilator action of NO on resistance vessels. The last 30 s of baseline, exercise or pGz, and recovery periods were analyzed.

RESULTS

Compared to baseline, light moderate exercise produced a nonsignificant rise of the a/b ratio. Both heavy moderate exercise and pGz produced statistically significant rises of peak and mean a/b ratios over baseline. Heavy moderate exercise produced a greater mean a/b ratio than pGz, but the peak a/b ratio did not differ between the two. Episodic rises and falls of a/b ratios were more common during pGz than exercise. Passive motorized cycling did not alter the a/b ratio.

CONCLUSIONS

Dicrotic notch descent occurs during a brief bout of moderate cycling exercise, consistent with NO release into circulation. pGz produces comparable descent, but passive motorized cycling does not. In terms of the beneficial effects of NO, this suggests that pGz might serve as a substitute in subjects who are physically incapable of exercising.

cDNA microarray analysis reveals novel candidate genes expressed in human peripheral blood following exhaustive exercise

It is generally accepted that exhausting endurance exercise exhibits strong effects on the immune system. Such effects have been attributed to changes in the cellular composition of peripheral blood as well as to changes in the expression of plausible candidate genes. The list of candidate genes is far from being complete, since this issue has not yet been investigated in a systematic way. In this study, we used a custom-made cDNA microarray focused on inflammation as a screening approach to study gene expression in eight one-half marathon runners before, immediately after, and 24 h after exercise. Significant differential gene expression was verified by quantitative real-time PCR. Linear regression analysis showed that microarray expression analysis of cell type-specific surface molecules reflects the observed individual cellular shifts in peripheral blood cells with high statistical significance. In line with the results of former studies, we observed an upregulation of mitogen-activated protein kinase-activated protein kinase-2 (MAPKAP-K2), l-selectin, and IL-1 receptor antagonist (IL-1ra) after exhaustive exercise. The main results of this study report, for the first time, the downregulation of CD81; the upregulation of thioredoxin, which may play an important part in anti-oxidative defense; and, surprisingly, the downregulation of the anti-carcinogenic gene glutathione- S-transferase-3 (GSTM3) in peripheral blood. The study shows cDNA microarray expression analysis as a reliable systematic instrument to complete the list of candidate genes that may play a role in exhaustive exercise-induced modulation of the immune response.

Changes in oxidative stress markers and NF-kappaB activation induced by sprint exercise

This study was aimed to investigate changes in blood markers of oxidative damage induced by short-term supramaximal anaerobic exercise and to determine whether oxidative stress was associated to activation of the redox-sensitive transcription factor nuclear factor-kappaB (NF-kappaB). Both a single Wingate test (WAnT) test and series of four WAnTs separated by 60 min rest intervals were carried out by eight professional cyclists. Leukocyte 8-OH-2-deoxyguanosine levels were significantly elevated 24 h after both exercise protocols. A significant decrease in blood reduced glutathione (GSH) concentration was observed immediately after and at 15, 60 and 120 min of the single WAnT, followed by a return to basal value after 24 h. This decrease was parallel to a significant increase of the oxidised/reduced glutathione (GSSG/GSH) ratio, to an activation of NF-kappaB and to a significant decrease in the protein level of its inhibitor IkappaB. GSH concentration and the GSSG/GSH ratio changed significantly for the first three of the WAnTs series and normalised thereafter. A significant activation of NF-kappaB and a decrease in the IkappaB protein level were also detected. We conclude that short-term supramaximal anaerobic exercise induces oxidative stress, as evidenced by non cumulative damage to macromolecules and changes in the glutathione status. Our data also indicate that high intensity anaerobic work gives rise to an activation of the transcription factor NF-kappaB accompanied by a degradation of IkappaB.

Periodic acceleration: effects on vasoactive, fibrinolytic, and coagulation factors

Cellular and isolated vessel experiments have shown that pulsatile and laminar shear stress to the endothelium produces significant release of mediators into the circulation. Periodic acceleration (pGz) applied to the whole body in the direction of the spinal axis adds pulses to the circulation, thereby increasing pulsatile and shear stress to the endothelium that should also cause release of mediators into the circulation. The purpose of this study was to determine whether addition of pulses to the circulation through pGzwould be sufficient to increase shear stress in whole animals and to acutely release mediators and how such a physical maneuver might affect coagulation factors. Randomized control experiments were performed on anesthetized, supine piglets. The treatment group (pGz) ( n = 12) received pGzwith a motion platform that moved them repetitively head to foot at ±0.4 g at 180 cpm for 60 min. The control group ( n = 6) was secured to the platform but remained on conventional ventilation throughout the 4-h protocol. Compared with control animals and baseline, pulsatile stress produced significant increases of serum nitrite, prostacyclin, PGE2, and tissue plasminogen activator antigen and activity, as well as D-dimer. There were no significant changes in epinephrine, norepinephrine, cortisol, and coagulation factors between groups or from baseline values. Pulsatile and laminar shear stress to the endothelium induced by pGzsafely produces increases of vasoactive and fibrinolytic activity. pGzhas potential to achieve mediator-related benefits from the actions of nitric oxide and prostaglandins.

Protection of Panax ginseng in injured muscles after eccentric exercise

Panax ginseng C.A. Meyer, the root of an Araliaceae plant has been shown to possess various biological effects. Ginseng treatment (100 mg kg(-1)) protected muscles from eccentric exercise injuries. It was effective in preserving mitochondrial membrane integrity and reduced nitrate concentration in vastus and rectus (46% and 26%, respectively). It also reduced carbonyl contents by approximately 27% in all the muscles studied.

Nuclear factor kappaB and activating protein 1 are involved in differentiation-related resistance to oxidative stress in skeletal muscle cells

Skeletal muscle cells are continuously exposed to oxidative stress. Thus, they compensate environmental challenges by increasing adaptive responses, characterized by activating protein 1 (AP-1)- and nuclear factor kappaB (NF-kappaB)-mediated transcriptional upregulation of endogenous enzymatic and nonenzymatic antioxidants. We investigated the crosstalk of molecules involved in redox signaling in muscle cells, by using the rat L6C5 and mouse C2C12 cell lines, which represent a useful experimental model for studying muscle metabolism. We analyzed specific antioxidant systems, including glutathione, thioredoxin reductase, and antioxidant enzymes, and the redox-sensitive transcription factors AP-1 and NF-kappaB, in both myoblasts and myotubes. We found that the high levels of NF-kappaB DNA binding activity and thioredoxin reductase, together with inhibitory AP-1 complexes, allowed increased expression of antioxidant enzymes and survival of C2C12 cells after oxidant exposure. On the contrary, L6C5 myoblasts had a sensitive phenotype, correlated with lower levels of thioredoxin reductase, catalase, and NF-kappaB activity and higher levels of GSSG and activating AP-1 complexes. Interestingly, this cell line acquired an apoptosis-resistant phenotype, accompanied by drastic changes in the oxidant/antioxidant balance, when induced to differentiate. In conclusion, the two cell lines, although similar in terms of growth and differentiation, displayed significant heterogeneity in terms of redox homeostasis.

Effects of exercise on gene expression in human peripheral blood mononuclear cells

Exercise leads to increases in circulating levels of peripheral blood mononuclear cells (PBMCs) and to a simultaneous, seemingly paradoxical increase in both pro- and anti-inflammatory mediators. Whether this is paralleled by changes in gene expression within the circulating population of PBMCs is not fully understood. Fifteen healthy men (18–30 yr old) performed 30 min of constant work rate cycle ergometry (∼80% peak O2 uptake). Blood samples were obtained preexercise (Pre), end-exercise (End-Ex), and 60 min into recovery (Recovery), and gene expression was measured using microarray analysis (Affymetrix GeneChips). Significant differential gene expression was defined with a posterior probability of differential expression of 0.99 and a Bayesian P value of 0.005. Significant changes were observed from Pre to End-Ex in 311 genes, from End-Ex to Recovery in 552 genes, and from Pre to Recovery in 293 genes. Pre to End-Ex upregulation of PBMC genes related to stress and inflammation [e.g., heat shock protein 70 (3.70-fold) and dual-specificity phosphatase-1 (4.45-fold)] was followed by a return of these genes to baseline by Recovery. The gene for interleukin-1 receptor antagonist (an anti-inflammatory mediator) increased between End-Ex and Recovery (1.52-fold). Chemokine genes associated with inflammatory diseases [macrophage inflammatory protein-1α (1.84-fold) and -1β (2.88-fold), and regulation-on-activation, normal T cell expressed and secreted (1.34-fold)] were upregulated but returned to baseline by Recovery. Exercise also upregulated growth and repair genes such as epiregulin (3.50-fold), platelet-derived growth factor (1.55-fold), and hypoxia-inducible factor-I (2.40-fold). A single bout of heavy exercise substantially alters PBMC gene expression characterized in many cases by a brisk activation and deactivation of genes associated with stress, inflammation, and tissue repair.

Impact of a competitive marathon race on systemic cytokine and neutrophil responses

PURPOSE

To investigate whether cytokines and neutrophils mediate exercise-related pathogenesis, we examined their responses and possible association after exhaustive exercise.

METHODS

Plasma and urine samples were obtained from 10 male runners before and after a 42.195-km marathon race. Major cytokines and neutrophil activation markers [myeloperoxidase (MPO) and lactoferrin (LTF)] were measured by enzyme-linked immunosorbent assays. Functional modulation of standard neutrophils and monocytes by plasma was determined on their luminol-dependent chemiluminescence responses.

RESULTS

The race induced peripheral neutrophilia accompanied by an increase in band neutrophils and monocytosis. Plasma MPO and LTF concentrations increased significantly by 1.8 and 1.4 times after the race. There was a greater increase in urine concentrations of MPO and LTF, 12.3 and 3.5 times after exercise, respectively, suggesting that neutrophil activation occurred and that renal clearance exceeded the increase in plasma concentrations. Plasma interleukin (IL)-6, IL-8, IL-10, granulocyte colony-stimulating factor (G-CSF), macrophage CSF (M-CSF), and monocyte chemotactic protein 1 (MCP-1) increased significantly after the race, and urine IL-1beta, IL-6, G-CSF, M-CSF, and MCP-1 increased significantly. The plasma IL-6 responses correlated with the increases of band neutrophil count (r = 0.860, P < 0.01), suggesting IL-6-mediated bone marrow release of neutrophils. Furthermore, the increases in urine MPO concentration were correlated with increases in urine IL-6 (r = 0.868, P < 0.01) and G-CSF (r = 0.875, P < 0.01), suggesting that these cytokines promoted neutrophil activation. However, preincubation of neutrophils and monocytes with postexercise plasma could not cause priming responses, possibly because of the exercise-induced enhancement of plasma antioxidant activity.

CONCLUSION

Although many cytokines recruiting and priming neutrophils and monocytes were secreted and functional after exhaustive exercise, overwhelming antioxidant and antiinflammatory defenses were induced, preventing exercise-induced oxidative stress.

Mitochondrial, sarcoplasmic membrane integrity and protein degradation in heart and skeletal muscle in exercised rats

Several different exercise regimens varied in the severity of tissue damage induced. Therefore, this study investigated the effects of a single bout of exercise versus endurance training in heart and skeletal muscles with different predominant fiber types on indices of mitochondrial, endoplasmic reticulum (ER) integrity and protein degradation. Male Wistar rats performed different treadmill exercise protocols: exhaustive, maximal exhaustive, eccentric, training and exhaustive exercise after training. The maximal and eccentric exercises resulted in a significant loss of integrity of the sarcoplasmic and ER muscle, while no changes were observed in cardiac muscle. Mitochondrial membrane fluidity measured by the fluorescence polarization method was significantly increased post-acute exercises in heart and oxidative muscles. Regular exercise can stabilize and preserve the viscoelastic nature of mitochondrial membranes in both tissues. The highest increase in carbonyl content was obtained in heart after exhaustive exercise protocol, from 1+/-0.1 to 3.6+/-0.14 nmol mg protein(-1), such increase were not found after regular exercise with values significantly decreased. Nitrate heart levels showed attenuated generation of nitric oxide after training. Muscle protein oxidation was produced in all exhaustive exercises including eccentric exercise.

A competitive marathon race decreases neutrophil functions in athletes

A full marathon is the longest running race in official track events and is a form of acute exercise. However, no studies have examined the acute neutrophil function response to a competitive marathon race. Thirty-six male athletes who had just completed the 42.195 km course of the 50th Beppu-Oita Mainichi Marathon were enrolled in this study. Neutrophil oxidative burst activity, phagocytic activity and expression of CD11b and CD16 per cell were measured by flow cytometry immediately before and after the marathon. Total leukocyte/neutrophil counts increased significantly (p < 0.001), whereas total oxidative burst activity per neutrophil cell decreased significantly after the race (p < 0.001). Furthermore, total phagocytic activity per neutrophil cell also decreased after the race, although it was not significant (p = 0.08). Although CD11b expression per cell did not change, the expression of CD16 per cell significantly decreased (p < 0.001) after the race. In conclusion, a competitive marathon race decreased neutrophil functions (oxidative burst activity and phagocytic activity), which may be partly due to a decrease in CD16 expression. The increase in total neutrophil counts might reflect a compensatory response to counteract the decrease in neutrophil functions.

Chronic exercise increases both inducible and endothelial nitric oxide synthase gene expression in endothelial cells of rat aorta

Chronic exercise upregulates endothelial nitric oxide synthase (eNOS) gene expression. Whether the expression of inducible nitric oxide synthase (iNOS) is affected by exercise is unknown. We therefore investigated the effects of chronic exercise on iNOS and eNOS expression in isolated rat aortic endothelial and smooth muscle cells separately. Five-week-old male Wistar rats were randomly divided into control and exercise groups. After 10 weeks of running training, animals were sacrificed under ether anesthesia. The standard curve quantitative competitive reverse transcriptase-polymerase chain reaction method was used to quantify NOS mRNA expression in isolated endothelial/smooth muscle cells. To evaluate the functional role of iNOS, we examined phenylephrine-induced vascular responses with or without pretreatment with aminoguanidine. We found that (1) expression of iNOS and eNOS mRNA in endothelial cells was increased by chronic exercise and (2) chronic exercise blunted phenylephrine-induced vascular responses, probably by increasing NO release via iNOS. Our results show that chronic exercise increases both iNOS and eNOS gene expression in endothelium. These alterations may be partially responsible for the change in vascular response after exercise.

Cytokine-like effects of prolactin in human mononuclear and polymorphonuclear leukocytes

Some biochemical events following the binding of prolactin (PRL) to its receptor in normal human leukocytes were investigated. PRL enhanced JAK2 phosphorylation in peripheral blood mononuclear cells (PBMC) but not in granulocytes. PRL also induced phosphorylation of Stat-5 in PBMC and Stat-1 in granulocytes. Subsequent binding of Stat-5- and of Stat-1-like molecules to a GAS responsive element from the beta-casein promoter was detected by EMSA. p38 MAPK (but not p42/p44 MAPK) was activated by PRL in both leukocyte populations. PRL induced iNOS and CIS mRNA expression in granulocytes. Increased expression of IRF-1 and SOCS-2 was observed in granulocytes and of SOCS-3 and iNOS in PBMC. Similar effects were obtained with ovine and human PRL. Antiserum to PRL reduced iNOS and IRF-1 expression induced by PRL in granulocytes and reduced iNOS expression in PBMC. Also, pretreatment of granulocytes with a p38 MAPK inhibitor (SB 203580) prevented in part PRL-induced iNOS and IRF-1 expression. In PBMC, the p38 inhibitor decreased PRL-induced iNOS gene expression. These results indicate that PRL-induced gene regulation in leukocytes requires the activation of at least two different pathways: the Stat and the MAP kinase pathways. Moreover, although PRL activates Stat in both leukocyte types, signal transduction is different in granulocytes and in PBMC. Most importantly, PRL modulates the expression of genes crucial to leukocyte function. The present findings reinforce the concept that PRL has "cytokine-like" activity in human leukocytes.

Cytokine changes after a marathon race

The influence of carbohydrate (1 l/h of a 6% carbohydrate beverage), gender, and age on pro- and anti-inflammatory plasma cytokine and hormone changes was studied in 98 runners for 1.5 h after two competitive marathon races. The marathoner runners were randomly assigned to carbohydrate (C, n = 48) and placebo (P, n = 50) groups, with beverages administered during the races in a double-blind fashion using color codes. Plasma glucose was higher and cortisol was lower in the C than in the P group after the race (P < 0.001). For all subjects combined, plasma levels of interleukin (IL)-10, IL-1 receptor antagonist (IL-1ra), IL-6, and IL-8 rose significantly immediately after the race and remained above prerace levels 1.5 h later. The pattern of change in all cytokines did not differ significantly between the 12 women and 86 men in the study and the 23 subjects > or =50 yr of age and the 75 subjects <50 yr of age. The pattern of change in IL-10, IL-1ra, and IL-8, but not IL-6, differed significantly between the C and the P group, with higher postrace values measured for IL-10 (109% higher) and IL-1ra (212%) in the P group and for IL-8 (42%) in the C group. In conclusion, plasma levels of IL-10, IL-1ra, IL-6, and IL-8 rose strongly in runners after a competitive marathon, and this was not influenced by age or gender. Carbohydrate ingestion, however, had a major effect in attenuating increases in cortisol and two anti-inflammatory cytokines, IL-10 and IL-1ra.