Effect of adrenergic blockade on lymphocyte cytokine production at rest and during exercise

Molecular investigation of the effect of weightlifting training on helper T cell subsets in female weightlifting athletes: an immune profiling panel

BACKGROUND

In this study, it was aimed to molecularly investigate the changes in the helper T (Th) cell subgroups of intense weightlifting training. For this purpose, transcription factor and cytokine expressions of Th1, Th2, Th17, and regulator T cell (Treg) cells were evaluated.

METHODS

Eight elite weightlifting athletes were included in the study. Within the scope of the study, transcription factor and cytokine expressions of Th cell subgroups were evaluated by real-time polymerase chain reaction (qPCR) method before training, after intense training with 90-100% capacity, and after 120 minutes of rest from training.

RESULTS

As a result of the study, when the pre-training and post-training expressions were compared, an increase in Th1 and Th2 cell factors and a decrease in Th17 and Treg cell-related expressions were detected. These changes were statistically significant (P<0.05). The changes in expressions after training and after 120 minutes of rest were not statistically significant (P>0.05).

CONCLUSIONS

Changes have been detected in Th cell subgroups due to intense weightlifting training, and these changes are the first study conducted with female weightlifters.

Targeted Lipidomics and Inflammation Response to Six Weeks of Sprint Interval Training in Male Adolescents

Lipids play an important role in coordinating and regulating metabolic and inflammatory processes. Sprint interval training (SIT) is widely used to improve sports performance and health outcomes, but the current understanding of SIT-induced lipid metabolism and the corresponding systemic inflammatory status modification remains controversial and limited, especially in male adolescents. To answer these questions, twelve untrained male adolescents were recruited and underwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygen consumption (VO2peak), biometric data (weight and body composition), serum biochemical parameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and targeted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1β, IL-2, IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β significantly decreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition, the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05, fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatory markers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, and FFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers and circulating lipid composition, offering health benefits to the population.

Selected Immunoendocrine Measures for Monitoring Responses to Training and Match Load in Professional Association Football: A Review of the Evidence

Biomarkers relating to player “stress balance,” immunological (ie, immunoglobulin-A), and hormonal (ie, testosterone and cortisol [T:C]) status are now commonly used in football. This article is our critical review of the scientific literature relating to the response of these measures to player load and their relationships with player health. The commonly reported relationship between immunoglobulin-A and training or match load highlights its sensitivity to changes in psychophysiological stress and the increased risk of compromised mucosal immunity. This is supported by its close relationship with symptoms of upper respiratory tract infection and its association with perceived fatigue in football players. Testosterone and cortisol concentrations and the testosterone–cortisol ratio are sensitive to changes in player load, but the direction of their response is often inconsistent and is likely influenced by player training status and non-sport-related stressors. Some evidence indicates that sustained periods of high training volume can increase resting testosterone and that sustained periods of low and high training intensity can increase resting cortisol, compromising the testosterone–cortisol ratio. These findings are noteworthy, as recent findings indicate interrelationships between testosterone, cortisol, and testosterone:cortisol and perceived measures of fatigue, sleep quality, and muscle soreness in football players. Variability in individual responses suggests the need for a multivariate and individualized approach to player monitoring. Overall, we consider that there is sufficient evidence to support the use of salivary immunoglobulin-A, testosterone, cortisol, and testosterone:cortisol measures as part of a multivariate, individualized player monitoring system in professional football.

Exercise, Immunity, and Illness

It is generally accepted that moderate amounts of exercise improve immune system functions and hence reduce the risk of infection whereas athletes engaged in regular prolonged and/or intensive training have a higher than “normal” incidence of minor infections, especially of the upper respiratory tract (URT, e.g., common cold and influenza). This is likely related to regular acute (and possibly chronic) periods of exercise-induced changes in immune function. URT infections can compromise performance directly if suffered shortly before or during competition or indirectly if suffered at other times via effects on training and/or physiological adaptations. This chapter covers the effects of exercise (acute and chronic), both positive and negative, on immune function and consequent infection risk, and considers the current state-of-the-art for monitoring and assessing this in athletes.

Omega-3 Polyunsaturated Fatty Acids: Benefits and Endpoints in Sport

The influence of nutrition has the potential to substantially affect physical function and body metabolism. Particular attention has been focused on omega-3 polyunsaturated fatty acids (n-3 PUFAs), which can be found both in terrestrial features and in the marine world. They are responsible for numerous cellular functions, such as signaling, cell membrane fluidity, and structural maintenance. They also regulate the nervous system, blood pressure, hematic clotting, glucose tolerance, and inflammatory processes, which may be useful in all inflammatory conditions. Animal models and cell-based models show that n-3 PUFAs can influence skeletal muscle metabolism. Furthermore, recent human studies demonstrate that they can influence not only the exercise and the metabolic response of skeletal muscle, but also the functional response for a period of exercise training. In addition, their potential anti-inflammatory and antioxidant activity may provide health benefits and performance improvement especially in those who practice physical activity, due to their increased reactive oxygen production. This review highlights the importance of n-3 PUFAs in our diet, which focuses on their potential healthy effects in sport.

Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan

Epidemiological evidence indicates that regular physical activity and/or frequent structured exercise reduces the incidence of many chronic diseases in older age, including communicable diseases such as viral and bacterial infections, as well as non-communicable diseases such as cancer and chronic inflammatory disorders. Despite the apparent health benefits achieved by leading an active lifestyle, which imply that regular physical activity and frequent exercise enhance immune competency and regulation, the effect of a single bout of exercise on immune function remains a controversial topic. Indeed, to this day, it is perceived by many that a vigorous bout of exercise can temporarily suppress immune function. In the first part of this review, we deconstruct the key pillars which lay the foundation to this theory-referred to as the "open window" hypothesis-and highlight that: (i) limited reliable evidence exists to support the claim that vigorous exercise heightens risk of opportunistic infections; (ii) purported changes to mucosal immunity, namely salivary IgA levels, after exercise do not signpost a period of immune suppression; and (iii) the dramatic reductions to lymphocyte numbers and function 1-2 h after exercise reflects a transient and time-dependent redistribution of immune cells to peripheral tissues, resulting in a heightened state of immune surveillance and immune regulation, as opposed to immune suppression. In the second part of this review, we provide evidence that frequent exercise enhances-rather than suppresses-immune competency, and highlight key findings from human vaccination studies which show heightened responses to bacterial and viral antigens following bouts of exercise. Finally, in the third part of this review, we highlight that regular physical activity and frequent exercise might limit or delay aging of the immune system, providing further evidence that exercise is beneficial for immunological health. In summary, the over-arching aim of this review is to rebalance opinion over the perceived relationships between exercise and immune function. We emphasize that it is a misconception to label any form of acute exercise as immunosuppressive, and, instead, exercise most likely improves immune competency across the lifespan.

Comparable Neutrophil Responses for Arm and Intensity-matched Leg Exercise

INTRODUCTION

Arm exercise is performed at lower absolute intensities than lower body exercise. This may impact on intensity-dependent neutrophil responses, and it is unknown whether individuals restricted to arm exercise experience the same changes in the neutrophil response as found for lower body exercise. Therefore, we aimed to investigate the importance of exercise modality and relative exercise intensity on the neutrophil response.

METHODS

Twelve moderately trained men performed three 45-min constant load exercise trials after determination of peak oxygen uptake for arm exercise (V˙O2peak arms) and cycling (V˙O2peak legs): 1) arm cranking exercise at 60% V˙O2peak arms, 2) moderate cycling at 60% V˙O2peak legs, and 3) easy cycling at 60% V˙O2peak arms.

RESULTS

Neutrophil numbers in the circulation increased for all exercise trials, but were significantly lower for easy cycling when compared with arm exercise (P = 0.009), mirroring the blunted increase in HR and epinephrine during easy cycling. For all trials, exercising HR explained some of the variation of the neutrophil number 2 h postexercise (R = 0.51-0.69), epinephrine explaining less of this variation (R = 0.21-0.34). The number of neutrophils expressing CXCR2 decreased in the recovery from exercise in all trials (P < 0.05).

CONCLUSIONS

Arm and leg exercise elicits the same neutrophil response when performed at the same relative intensity, implying that populations restricted to arm exercise might achieve a similar exercise induced neutrophil response as those performing lower body exercise. A likely explanation for this is the higher sympathetic activation and cardiac output for arm and relative intensity-matched leg exercise when compared with easy cycling, which is partly reflected in HR. This study further shows that the downregulation of CXCR2 may be implicated in exercise-induced neutrophilia.

T-cells and their cytokine production: The anti-inflammatory and immunosuppressive effects of strenuous exercise

Strenuous exercise bouts and heavy training are associated with a heightened anti-inflammatory state and a transient suppression of several immune components. In turn, many athletes are susceptible to illness, particularly upper respiratory symptoms (e.g. cough, sore throat, running nose). T-lymphocytes (T-cells) are important for orchestrating the immune response and can be categorised into subsets according to their phenotypical characteristics resulting from polarisation (i.e. type-1, type-2 and regulatory T-cells). Each T-cell subset has a unique functional role, including their capacity to produce pro- and anti-inflammatory cytokines in response to an immune challenge. Prolonged and exhaustive exercise typically reduces peripheral blood type-1 T-cell number and their capacity to produce the pro-inflammatory cytokine, interferon-γ. Moreover, heavy training loads are associated with elevated numbers of resting peripheral blood type-2 and regulatory T-cells, which characteristically produce the anti-inflammatory cytokines, interleukin-4 and interleukin-10, respectively. This appears to increase the risk of upper respiratory symptoms, potentially due to the cross-regulatory effect of interleukin-4 on interferon-γ production and immunosuppressive action of IL-10. Catecholamines significantly influence the number of peripheral blood T-cells in response to exercise. Whereas, glucocorticoids and prostaglandin E2 promote the production of anti-inflammatory cytokines by T-cells. In summary, strenuous exercise bouts and heavy training shifts T-cell immunity towards an anti-inflammatory state. This impairs the ability of the immune system to mount an inflammatory response to an immune challenge, which may weaken defences against intracellular pathogens (e.g. viruses), and increase the risk of infection and viral reactivation.

Arm and Intensity-Matched Leg Exercise Induce Similar Inflammatory Responses

INTRODUCTION

The amount of active muscle mass can influence the acute inflammatory response to exercise, associated with reduced risk for chronic disease. This may affect those restricted to upper body exercise, for example, due to injury or disability. The purpose of this study was to compare the inflammatory responses for arm exercise and intensity-matched leg exercise.

METHODS

Twelve male individuals performed three 45-min constant load exercise trials after determination of peak oxygen uptake for arm exercise (V˙O2peak A) and cycling (V˙O2peak C): 1) arm cranking exercise at 60% V˙O2peak A, 2) moderate cycling at 60% V˙O2peak C, and 3) easy cycling at 60% V˙O2peak A. Cytokine, adrenaline, and flow cytometric analysis of monocyte subsets were performed before and up to 4 h postexercise.

RESULTS

Plasma IL-6 increased from resting concentrations in all trials; however, postexercise concentrations were higher for arm exercise (1.73 ± 1.04 pg·mL) and moderate cycling (1.73 ± 0.95 pg·mL) compared with easy cycling (0.87 ± 0.41 pg·mL; P < 0.04). Similarly, the plasma IL-1ra concentration in the recovery period was higher for arm exercise (325 ± 139 pg·mL) and moderate cycling (316 ± 128 pg·mL) when compared with easy cycling (245 ± 77 pg·mL, P < 0.04). Arm exercise and moderate cycling induced larger increases in monocyte numbers and larger increases of the classical monocyte subset in the recovery period than easy cycling (P < 0.05). The postexercise adrenaline concentration was lowest for easy cycling (P = 0.04).

CONCLUSIONS

Arm exercise and cycling at the same relative exercise intensity induces a comparable acute inflammatory response; however, cycling at the same absolute oxygen uptake as arm exercise results in a blunted cytokine, monocyte, and adrenaline response. Relative exercise intensity appears to be more important to the acute inflammatory response than modality, which is of major relevance for populations restricted to upper body exercise.

Fit with good fat? The role of n-3 polyunsaturated fatty acids on exercise performance

N-3 PUFA (n-3) polyunsaturated fatty acids (PUFA) are a family of fatty acids mainly found in oily fish and fish oil supplements. The effects of n-3 PUFA on health are mainly derived from its anti-inflammatory proprieties and its influence on immune function. Lately an increased interest in n-3 PUFA supplementation has reached the world of sport nutrition, where the majority of athletes rely on nutrition strategies to improve their training and performance. A vast amount of attention is paid in increasing metabolic capacity, delaying the onset of fatigue, and improving muscle hypertrophy and neuromuscular function. Nutritional strategies are also frequently considered for enhancing recovery, improving immune function and decreasing oxidative stress. The current review of the literature shows that data regarding the effects of n-3PUFA supplementation are conflicting and we conclude that there is, therefore, not enough evidence supporting a beneficial role on the aforementioned aspects of exercise performance.

Exercise-Dependent Regulation of NK Cells in Cancer Protection

Natural killer (NK) cells are the most responsive immune cells to exercise, displaying an acute mobilization to the circulation during physical exertion. Recently, exercise-dependent mobilization of NK cells was found to play a central role in exercise-mediated protection against cancer. Here, we review the link between exercise and NK cell function, focusing on circulating exercise factors and additional effects, including vascularization, hypoxia, and body temperature in mediating the effects on NK cell functionality. Exercise-dependent mobilization and activation of NK cells provides a mechanistic explanation for the protective effect of exercise on cancer, and we propose that exercise represents a potential strategy as adjuvant therapy in cancer, by improving NK cell recruitment and infiltration in solid tumors.

Hot water immersion induces an acute cytokine response in cervical spinal cord injury

PURPOSE

The dysfunctional sympathetic nervous system in individuals with cervical spinal cord injury (CSCI) impairs adrenergic responses and may, therefore, contribute to the blunted post-exercise cytokine response. The purpose of this study was to investigate an alternative way to exercise to induce an acute cytokine response by passive core temperature elevation in CSCI.

METHODS

Seven male participants with a motor complete CSCI and 8 male able-bodied controls were immersed for 60 min in water set at a temperature 2 °C above the individuals' resting oesophageal temperature. Blood was collected pre, post, and every hour up to 4 h post-immersion.

RESULTS

Hot water immersion resulted in an IL-6 plasma concentration mean increase of 133 ± 144 % in both groups (P = 0.001). On a group level, IL-6 plasma concentrations were 68 ± 38 % higher in CSCI (P = 0.06). In both groups, IL-8 increased by 14 ± 11 % (P = 0.02) and IL-1ra by 18 ± 17 % (P = 0.05). Catecholamine plasma concentrations were significantly reduced in CSCI (P < 0.05) and did not increase following immersion.

CONCLUSIONS

Passive elevation of core temperature acutely elevates IL-6, IL-8 and IL-1ra in CSCI despite a blunted adrenergic response, which is in contrast to earlier exercise interventions in CSCI. The present study lays the foundation for future studies to explore water immersion as an alternative to exercise to induce an acute cytokine response in CSCI.

Influence of Hydration Status on Changes in Plasma Cortisol, Leukocytes, and Antigen-Stimulated Cytokine Production by Whole Blood Culture following Prolonged Exercise

Elevated antigen-stimulated anti-inflammatory cytokine production appears to be a risk factor for upper respiratory tract illness in athletes. The purpose of this study was to determine the effects of prolonged exercise and hydration on antigen-stimulated cytokine production. Twelve healthy males cycled for 120 min at 60% V˙O2max⁡ on two occasions, either euhydrated or moderately hypohydrated (induced by fluid restriction for 24 h). Blood samples were collected before and after exercise and following 2 h recovery for determination of cell counts, plasma cortisol, and in vitro antigen-stimulated cytokine production by whole blood culture. Fluid restriction resulted in mean body mass loss of 1.3% and 3.9% before and after exercise, respectively. Exercise elicited a significant leukocytosis and elevated plasma cortisol, with no differences between trials. IL-6 production was significantly reduced 2 h postexercise (P < 0.05), while IL-10 production was elevated postexercise (P < 0.05). IFN-γ and IL-2 production tended to decrease postexercise. No significant effect of hydration status was observed for the measured variables. Prolonged exercise appears to result in augmented anti-inflammatory cytokine release in response to antigen challenge, possibly coupled with acute suppression of proinflammatory cytokine production, corresponding with studies using mitogen or endotoxin as stimulant. Moderate hypohydration does not appear to influence these changes.

Acute aerobic exercise in humans increases cytokine expression in CD27(-) but not CD27(+) CD8(+) T-cells

Exercise alters the percentage of CD8(+) T-cells in the bloodstream expressing type I and type II cytokines. It is unknown if this reflects a change in cytokine expression within individual cells, or whether these observations result from the exercise-induced shift in the proportions of early/intermediate (CD27(+)) and late (CD27(-)) differentiated cells, which have vastly different cytokine profiles. 16 males cycled for 60 min at 95% maximal steady state. Mononuclear cells isolated from blood collected before, immediately after, and 1 h after exercise were cultured overnight with and without phytohaemagglutinin stimulation. CD8(+) T-cells were assessed for differentiation markers and intracellular cytokine expression by flow cytometry. The numbers and percentage of CD27(-)CD8(+) T-cells increased immediately after exercise and fell below pre-exercise values 1 h later. At 1 h after exercise, an increased number and percentage of CD8(+) T-cells expressing IL-2, IFN-γ, TNF-α, IL-6, IL-4, and IL-10 was observed in both stimulated and unstimulated cells. The cytokine response to exercise was confined to CD27(-)CD8(+) T-cells, although cytokine expression among CD8(+) T-cells was highest when the proportion of CD27(-)CD8(+) T-cells was lowest. Moreover, the cytokine response to exercise could be predicted by the number of late cells in resting blood: cytokine expression was highest among those with low resting proportions of late cells. We conclude that exercise-induced changes in the percentage of CD8(+) T-cells expressing cytokines are not due to proportional shifts in early/intermediate and late differentiated T-cells. Exercise may prime late-differentiated blood CD8(+) T-cells to initiate effector functions in preparation for their extravasation into the tissues.

Fish oil supplementation augments post-exercise immune function in young males

PURPOSE

Fish oils and related fatty acid components have anti-inflammatory properties, with beneficial effects against various disorders such as cardiovascular disease. A single bout of exercise can alter immune function. However, the effects of fish oil on immune function after a single bout of exercise are currently unknown. This study investigated the effect of supplementation with fish oil on the immune response to an acute bout of endurance exercise.

METHODS

Sixteen male subjects underwent a six week double blind randomised placebo controlled supplementation trial involving two groups (fish oil or placebo oil, 3g/day). They attended for two visits, the first involving a maximal exercise test and the second involving a 1-h bout of endurance exercise on a cycle ergometer at 70% (V)O(2peak). Blood samples were taken pre-supplementation, pre-exercise (post-supplementation), immediately, 1 and 3h post-exercise. Samples were analysed for plasma IL-6, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and cortisol; peripheral blood mononuclear cell (PBMC) IL-2, IL-4 and IFN-γ production; neutrophil phagocytosis/oxidative burst; and natural killer (NK) cell cytotoxic activity.

RESULTS

Post-supplementation EPA concentration was increased (P=0.0127) in the fish oil group. At 3h post-exercise PBMC IL-2 (P=0.0067) and NK cell activity (P=0.0163) was greater in the fish oil compared with the control group. However, PBMC IL-4 and IFN-γ productions, plasma IL-6 and cortisol concentrations, as well as neutrophil activity were unaffected by fish oil supplementation.

CONCLUSION

The current study demonstrates that fish oil supplementation reduces increases PBMC IL-2 production and NK cell cytotoxic activity in the recovery period after exercise.

Rhodiola algida improves chemotherapy-induced oral mucositis in breast cancer patients

OBJECTIVE

Oral ulcerative mucositis, a common adverse effect due to mainstream cytotoxic drugs, limits the nutritional intake of cancer patients. Rhodiola algida is widely used in traditional Chinese medicine to stimulate the immune system. The aim of this study is to investigate the effect of this herbal extract on healthy human lymphocytes in vitro, the homeostasis of cancer patients and the healing time of oral ulcers.

METHOD

The constituents of Rhodiola algida were analyzed by RP-HPLC. Lymphocytes isolated from 462 healthy subjects were treated with 100 ug/ml Rhodiola algida for 48 h. The activity of the cells was measured by cell proliferation reagent and ATP assay. The level of various cytokines and mRNA content of lymphocytes were determined. Rhodiola algida demonstrated no toxicity in animals, which had been orally fed with 1 mg/ml Rhodiola algida for 30 days. 130 breast cancer patients from Huaxi Hospital of Sichuan University were recruited between 2006 and 2007. They received four cycles of 5-fluorouracil, epirubicin and cyclophosphamide after modified total mastectomy. These patients were randomly assigned to test and control groups. Rhodiola algida mixture was consumed by the test group for 14 consecutive days after each cycle of chemotherapy. All patients were given 0.2% chlorohexidine mouth wash to be used every day. Complete blood counts, liver and renal function tests together with the number and size of oral ulcerations were analyzed after each cycle. Weight loss, complaints of nausea or vomiting and degree of pain were noted.

RESULTS

The optimal concentration of Rhodiola algida favored the proliferation of lymphocytes. The levels of IL-2, IL-4, granulocyte-macrophage colony-stimulating factor and the mRNA content of these cytokines were also enhanced. White blood cell (WBC) levels returned to normal range in both groups 1 week after every cycle of chemotherapy. WBC count increased faster in patients using Rhodiola algida; they presented with smaller and fewer oral ulcers. There were no liver or renal complications observed in any patients.

CONCLUSION

Rhodiola algida increases immunity of patients who are receiving chemotherapy post mastectomy and decreases the quantity of oral ulcers. Thus Rhodiola algida has the potential to be used concurrently with chemotherapy to alleviate the occurrence of oral ulcers.

Modulation of inflammatory response via alpha2-adrenoceptor blockade in acute murine colitis

Inflammatory bowel disease (IBD) is characterized by heavy production of proinflammatory cytokines such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta. Interactions of the autonomic nervous system with local immune cells play an important role in the development of IBD, and the balance of autonomic nerve function is broken in IBD patients with sympathetic overactivity. However, the function of catecholamines in the progress of colitis is unclear. In this study, we examined the role of catecholamines via alpha2-adrenoreceptor in acute murine colitis. The expression of tyrosine hydroxylase (TH) and dopamine b-hydroxylase (DBH), two rate-limiting enzymes in catecholamine synthesis, was detected by immunohistochemistry in murine colitis. Murine colitis was induced by dextran sodium sulphate or trinitrobenzene sulphonic acid (TNBS), and the mice were administered RX821002 or UK14304, alpha2-adrenoceptor antagonists or agonists. Colitis was evaluated by clinical symptoms, myeloperoxidase assay, TNF-alpha and IL-1beta production and histology. Lamina propria mononuclear cells (LPMCs) from mice with TNBS colitis were cultured in the absence or presence of RX821002 or UK14304, and stimulated further by lipopolysaccharide. TH and DBH are induced in LPMCs of inflamed colon, the evidence of catecholamine synthesis during the process of colitis. RX821002 down-regulates the production of proinflammatory cytokines from LPMCs, while UK14304 leads to exacerbation of colitis. Together, our data show a critical role of catecholamines via alpha2-adrenoreceptors in the progress of acute colitis, and suggest that use of the alpha2-adrenoceptor antagonist represents a novel therapeutic approach for the management of colitis.

The effects of acute exercise-induced cortisol on CCR2 expression on human monocytes

CC-chemokine receptor 2 (CCR2) and its ligand, monocyte chemotactic protein-1 (MCP-1, also known as CCL2), are crucial for the recruitment of monocytes/macrophages to sites of inflammation. We conducted a series of experiments to investigate the relationship between stress, monocyte CCR2 expression and migration activity. First, we collected peripheral blood mononuclear cells (PBMC) from untrained subjects (n=8) and measured CCR2 expression on CD14(+) monocytes cultured with cortisol, epinephrine and norepinephrine. Second, we collected PBMC from the subjects before and after they cycled for 60 min at 70% peak O(2) uptake (VO2(peak)), and measured alterations in CCR2 expression on monocytes following exercise. Third, we cultured PBMC with serum obtained before and after exercise and the glucocorticoid antagonist RU-486 to determine the effect of cortisol on CCR2 expression in vitro. Last, we measured the ability of PBMC treated with serum or cortisol to migrate through membrane filters in response to CCL2. Cortisol (but not epinephrine or norepinephrine) increased CCR2 expression on monocytes in a dose- and time-dependent manner. Exercise did not influence CCR2 expression on PBMC, whereas incubation of PBMC with post-exercise serum significantly increased CCR2 expression. Both cortisol and post-exercise serum increased the migration of PBMC toward CCL2. The increase in CCR2 expression on PBMC following stimulation with cortisol and serum was blocked by the glucocorticoid receptor antagonist RU-486. In conclusion, cortisol released during exercise increased monocyte CCR2 expression and migration activity in vitro. These alterations may influence inflammation and regeneration of damaged tissue after acute stress.

Catecholamines-crafty weapons in the inflammatory arsenal of immune/inflammatory cells or opening pandora's box?

It is well established that catecholamines (CAs), which regulate immune and inflammatory responses, derive from the adrenal medulla and from presynaptic neurons. Recent studies reveal that T cells also can synthesize and release catecholamines which then can regulate T cell function. We have shown recently that macrophages and neutrophils, when stimulated, can generate and release catecholamines de novo which, then, in an autocrine/paracrine manner, regulate mediator release from these phagocytes via engagement of adrenergic receptors. Moreover, regulation of catecholamine-generating enzymes as well as degrading enzymes clearly alter the inflammatory response of phagocytes, such as the release of proinflammatory mediators. Accordingly, it appears that phagocytic cells and lymphocytes may represent a major, newly recognized source of catecholamines that regulate inflammatory responses.

Serum from exercising humans suppresses t-cell cytokine production

Exercise affects t-cell cytokine production. Whether or not these effects are caused by circulating factors associated with physical activity (e.g., inflammatory mediators, acidosis) is unknown. To investigate this, we incubated sera (10%), obtained from 16 young-adults before (PRE) and after (END) 30-min of exercise, with commercially available Jurkat cells, a t-lymphocyte model, that, of course, had never been exposed to an exercise milieu. After 1 and 6h in culture, we measured in the supernatant four cytokines (each known to be altered by exercise and involved in disease pathophysiology): IL-2, TGF-beta1, TNF-alpha, and IL-1ra. Cell proliferation was assessed with proliferating nuclear cell antigen (PNCA). Statistical analysis consisted of a linear mixed model for repeated measurement. There was no effect of exercise on t-cell production of either TGF-beta1 or IL-1ra. In contrast, both IL-2 (p=0.025) and TNF-alpha (p=0.031) production was significantly suppressed in sera from the exercising participants. The suppression of these two cytokines occurred despite the fact that PNCA significantly increased (p=0.0004) in the END serum. In conclusion, exercise alters circulating factors that can, subsequently, influence t-cell cytokine production in vitro.

Dangerous exercise: lessons learned from dysregulated inflammatory responses to physical activity

Exercise elicits an immunological “danger” type of stress and inflammatory response that, on occasion, becomes dysregulated and detrimental to health. Examples include anaphylaxis, exercise-induced asthma, overuse syndromes, and exacerbation of intercurrent illnesses. In dangerous exercise, the normal balance between pro- and anti-inflammatory responses is upset. A possible pathophysiological mechanism is characterized by the concept of exercise modulation of previously activated leukocytes. In this model, circulating leukocytes are rendered more responsive than normal to the immune stimulus of exercise. For example, in the case of exercise anaphylaxis, food-sensitized immune cells may be relatively innocuous until they are redistributed during exercise from gut-associated circulatory depots, like the spleen, into the central circulation. In the case of asthma, the prior activation of leukocytes may be the result of genetic or environmental factors. In the case of overuse syndromes, the normally short-lived neutrophil may, because of acidosis and hypoxia, inhibit apoptosis and play a role in prolongation of inflammation rather than healing. Dangerous exercise demonstrates that the stress/inflammatory response caused by physical activity is robust and sufficiently powerful, perhaps, to alter subsequent responses. These longer term effects may occur through as yet unexplored mechanisms of immune “tolerance” and/or by a training-associated reduction in the innate immune response to brief exercise. A better understanding of sometimes failed homeostatic physiological systems can lead to new insights with significant implication for clinical translation.

A final common pathway for depression: implications for therapy

Depression in humans and animal models has been found to be accompanied by a hypoactivity of brain regions involved in positively motivated behavior together with a hyperactivity in regions involved in stress responses. Both sets of changes are reversed by diverse antidepressant treatments. It has been proposed that this neural pattern underlies the symptoms common to most forms of depression, which are the loss of positively motivated behavior and the increase in stress. The present paper discusses how this framework can organize diverse findings on the multiple factors associated with this disorder. The hypothesis suggests new therapeutic strategies involving treatment with low-dose corticosteroids to suppress the stress network or with antagonists of alpha(1A)- and agonists of alpha(1B)-adrenoceptors to disinhibit or activate the positive motivational network, respectively.

The immunopotentiator effects of nefopam

The effects of opiate analgesics and non-steroidal anti-inflammatory drugs on the immune functions have been reported. The effect of the non-opiate analgesic nefopam on the immune functions has not yet been investigated. Male Swiss albino mice were treated with either heat killed E. coli or saline. They were classified into 12 groups. The effects of subacute (15 mg/kg/12 h S.C. daily for one week) and chronic (10 mg/kg/12 h S.C. daily for one month) treatment with nefopam on the levels of interferon-gamma (IFN-gamma) and total immunoglobulins were examined in both normal and immunized mice. Also, the effect of the chronic administration of nefopam on the phagocytic activity of peritoneal macrophage was evaluated in both normal and immunized mice. Subacute and chronic administration of nefopam induced no significant raise in the level of interferon-gamma (IFN-gamma) or in the level of total immunoglobulins in non-immunized animals, while subacute and chronic treatment with nefopam augmented markedly the immunization induced increase of level of interferon-gamma (IFN-gamma). Furthermore, chronic treatment with nefopam potentiated significantly the production of total immunoglobulin induced by heat killed E. coli. Chronic treatment with nefopam also was associated with significant enhancement of innate immune response reflected in the pronounced increase in the phagocytic activity of macrophages in non-immunized and immunized animals. The enhancement of phagocytic activity of macrophages by nefopam in immunized animals was significantly higher than that of non-immunized animals. These findings revealed that nefopam has the ability to trigger the immune response for bacterial antigen. The mechanism behind the immunostimulatory effect of nefopam requires further investigation, but it may be due, at least in part, to the inhibitory effect of nefopam on the serotonin and norepinephrine reuptake at nerve endings. In conclusion, our findings postulated that nefopam stimulated the immune functions and improved the defence mechanism. This information may be of future therapeutic value in diseases that need immunologic enhancement.

Carbohydrate consumption during cycling increases in vitro NK cell responses to IL-2 and IFN-gamma

INTRODUCTION

Exercise has been shown to lower blood natural killer cell concentration and activity for up to 24-h after exercise; however, the mechanism underlying this effect is not clearly defined. We have speculated that an exercise-induced change in T-cell control of NK cells is at least partly responsible for the post-exercise suppression. As a follow-up to our previous research, the purpose of this study was to examine the T and NK cells responses during and following moderate/high-intensity endurance exercise.

METHODS

Eight male subjects (20+/-1 y; VO(2peak)=67.22+/-2.79 mL.kg(-1).mL(-1)) were recruited to complete two 1-h (75-80% VO(2peak)) cycling trials in a random counterbalanced order: carbohydrate (CHO) and placebo (PLA). Venous blood samples were collected before (PRE), immediately (POST), 2-h (2H), and 4-h (4H) after exercise. NK (CD3(-)/56(+)) and activated NK (CD3(-)/56(+)/69(+)) number were measured using flow cytometry. NK cell activity (NKCA) was determined using both a (51)Cr release assay (NKCA-51) and activated NK cell number (NKCA-69). Whole blood samples were stimulated with IL-2, IFN-gamma, IL-4, IL-12, and no stimulation for 12-h and then analyzed for NK cell activity using a (51)Cr release assay (NKCA-51).

RESULTS

Leukocyte counts and unstimulated NKCA were not different between CHO and PLA; however, exercise significantly increased NKCA (P<.05). Fold change in IL-2, IFN-gamma, and IL-2+IFN-gamma-stimulated NKCA were significantly greater in CHO compared to PLA (P<.05). No effect of drink was found for IL-4, IL-12, and IL-4+IL-12-stimulated NKCA.

DISCUSSION

The fold change in IL-2-stimulated NKCA is consistant with our previous published work. The drink effect for Th1 (but not Th2) cytokines suggests they may play a more significant role in modulating NKCA following a strenuous bout of aerobic exercise when CHO is consumed.

Constitutive pro- and anti-inflammatory cytokine and growth factor response to exercise in leukocytes

Leukocytosis following exercise is a well-described phenomenon of stress/inflammatory activation in healthy humans. We hypothesized that, despite this increase in circulating inflammatory cells, exercise would paradoxically induce expression of both pro- and anti-inflammatory cytokines and growth factors within these cells. To test this hypothesis, 11 healthy adult men, 18–30 yr old, performed a 30-min bout of heavy cycling exercise; blood sampling was at baseline, end-exercise, and 60 min into recovery. The percentage of leukocytes positive for intracellular cytokines and growth factors and mean fluorescence intensity was obtained by flow cytometry. Proinflammatory cytokines (IL-1α, IL-2, IFN-γ, and TNF-α), a pleiotropic cytokine (IL-6), and anti-inflammatory cytokines and growth factors [IL-4, IL-10, growth hormone (GH), and IGF-I] were examined. Median fluorescence intensity was not affected by exercise; however, we found a number of significant changes ( P < 0.05 by mixed linear model and modified t-test) in the numbers of circulating cells positive for particular mediators. The pattern of expression reflected both pro- and anti-inflammatory functions. In T-helper lymphocytes, TNF-α, but also IL-6, and IL-4 were significantly increased. In monocytes, both IFN-γ and IL-4 increased. B-lymphocytes positive for GH and IGF-I increased significantly. GH-positive granulocytes also significantly increased. Collectively, these observations indicate that exercise primes an array of pro- and anti-inflammatory and growth factor expression within circulating leukocytes, perhaps preparing the organism to effectively respond to a variety of stressors imposed by exercise.

Lymphocyte responses to influenza and tetanus toxoid in vitro following intensive exercise and carbohydrate ingestion on consecutive days

The effect of carbohydrate (CHO) ingestion on antigen- (rather than mitogen-) stimulated T-cell responses to prolonged, intensive exercise may give a more realistic insight into the effect of CHO on T-cell functional capacity and subsequent infection risk. This study investigated the effect of CHO ingestion during prolonged, intensive exercise on influenza- and tetanus toxoid-stimulated T-cell cytokine mRNA expression and proliferation. Mitogen- [phytohemagglutinin (PHA)] stimulated proliferation was assessed for comparison. Responses were assessed following exercise on consecutive mornings to determine any carryover effect. Fifteen male games players performed two exercise trials in a double-blind, randomized, crossover design. Each trial comprised 90 min of intensive, intermittent running on consecutive mornings, with either CHO (6.4% wt/vol) or placebo (PLA) beverage ingestion before, during, and after each bout of exercise. Postexercise CD3(+) cell counts were higher in PLA than CHO on both days (P < 0.05). Antigen-stimulated T-cell cytokine mRNA expression was unaffected by exercise or CHO ingestion. Before exercise on day 2, T-cell proliferative responses to PHA, influenza, and tetanus toxoid were higher in CHO than PLA by 99, 80, and 58%, respectively (P < 0.01 for PHA, P < 0.05 for influenza and tetanus toxoid). At 1 h postexercise on day 2, PHA-induced proliferation was 70% higher in CHO than PLA (P < 0.05), yet there were no differences between trials for antigen-induced proliferative responses. Therefore, mitogen-induced T-cell proliferation following strenuous exercise and CHO does not necessarily reflect responses to specific antigens and, consequently, may not provide a good model for the situation in vivo.

Effect of prolonged exercise and carbohydrate ingestion on type 1 and type 2 T lymphocyte distribution and intracellular cytokine production in humans

The present study was undertaken to examine the role of the exercise-induced stress hormone response on the regulation of type 1 and type 2 T lymphocyte intracellular cytokine production. Subjects performed 2.5 h of cycling exercise at 65% maximal O2 uptake while ingesting a 6.4% carbohydrate (CHO) solution, 12.8% CHO solution, or a placebo. Peripheral whole blood samples were stimulated and stained for T lymphocyte surface antigens (CD4 and CD8). Cells were then permeabilized, stained for intracellular cytokines, and analyzed using flow cytometry. Exercise resulted in a decrease (P < 0.05) in the number and percentage of IFN-gamma positive CD4+ and CD8+ T lymphocytes. These stimulated cells produced less IFN-gamma immediately postexercise (P < 0.05) and 2-h postexercise (P < 0.05) compared with preexercise. However, CHO ingestion, which attenuated the exercise-induced stress hormone response compared with placebo (P < 0.05), prevented both the decrease in the number and percentage of IFN-gamma-positive CD4+ and CD8+ T lymphocytes and the suppression of IFN-gamma production from stimulated CD4+ and CD8+ T lymphocytes. There was no effect of exercise on the number of, or cytokine production from, IL-4-positive CD4+ or CD8+ T lymphocytes. These data provide support for the role of exercise-induced elevations in stress hormones in the regulation of type 1 T lymphocyte cytokine production and distribution.

Immune responses to strenuous exercise and carbohydrate intake in boys and men

Few studies describe immune responses to exercise in children, compared with adults, and none have investigated the influence of carbohydrate (CHO) intake. We hypothesized less perturbation and a faster recovery of the immune system with exercise in children, regardless of supplemental energy. Twelve boys (9.8 +/- 0.1 y) and 10 men (22.1 +/- 0.5 y) cycled for 60 min at 70% o(2max) while drinking 6% CHO (CHO-T) or flavored water (FW-T). Blood samples were collected before (PRE), immediately after (POST), and 60 min after (REC) exercise. Boys, compared with men, had smaller (p < 0.05) increases in total leukocytes (28% versus 38%), natural killer (NK) cells (78% versus 236%), and NK T cells (42% versus 128%) at POST, averaged across beverage trials. Exercise did not increase tumor necrosis factor-alpha (TNF-alpha), but significantly (p < 0.05) increased IL-6 in men (189%), but not in boys (11%). In both trials, lymphocytes and T cells at REC were suppressed (p < 0.05), relative to PRE, in men (-21%), but not in boys (4%). IL-6 remained elevated ( p< 0.001) in men at REC, with no change from POST in boys. In boys, but not in men, CHO significantly (p < 0.05) attenuated increases in neutrophil, lymphocyte, and NK cell counts at POST. Neutrophils at REC in CHO-T were lower (p < 0.05) than in FW-T in men ( approximately 25%) and in boys ( approximately 17%). CHO had no effect on TNF-alpha or IL-6 in either group. Our results indicate a distinct pattern of the immune response to exercise and CHO intake in boys, compared with men.

DIFFERENTIAL NEURAL CONTROL OF GLOMERULAR ULTRAFILTRATION

The renal nerves constrict the renal vasculature, causing decreases in renal blood flow (RBF) and glomerular filtration rate (GFR). Whether renal haemodynamics are influenced by changes in renal nerve activity within the physiological range is a matter of debate. We have identified two morphologically distinct populations of nerves within the kidney, which are differentially distributed to the renal afferent and efferent arterioles. Type I nerves almost exclusively innervate the afferent arteriole whereas type II nerves are distributed equally on the afferent and efferent arterioles. We have also demonstrated that type II nerves are immunoreactive for neuropeptide Y, whereas type I nerves are not. This led us to hypothesize that, in the kidney, distinct populations of nerves innervate specific effector tissues and that these nerves may be selectively activated, setting the basis for the differential neural control of GFR. In physiological studies, we demonstrated that differential changes in glomerular capillary pressure occurred in response to graded reflex activation of the renal nerves, compatible with our hypothesis. Thus, sympathetic outflow may be capable of selectively increasing or decreasing glomerular capillary pressure and, hence, GFR by differentially activating separate populations of renal nerves. This has important implications for our understanding of the neural control of body fluid balance in health and disease.

Carbohydrate intake during endurance exercise increases natural killer cell responsiveness to IL-2

The purpose of this study was to evaluate the effect of high-intensity endurance exercise and carbohydrate consumption on in vitro responsiveness of natural killer (NK) to IL-2 (2.5 U/ml for 24 h). Thirteen male subjects (18-26 yr old; peak O2 consumption = 59.79 +/- 5.13 ml.kg-1.ml-1) were recruited to complete two 1-h (75-80% peak O2 consumption) cycling trials in a random counterbalanced order: carbohydrate (CHO) and placebo (Pla). Venous blood samples were collected before (Pre), immediately (Post), 2 h (2H), and 4 h (4H) after exercise. All resting samples were taken after 15 min of seated rest. NK (CD3-/56+), activated NK (CD3-/56+/69+), helper T cell (Th; CD3+/4+), and cytotoxic T cell (Tc; CD3+/8+) number were measured by using flow cytometry. NK cell activity (NKCA) was determined by using both a 51Cr release assay (NKCA-51) and activated NK cell number (NKCA-69). Immune system variables were not different between CHO and Pla, with the exception of NK cell responsiveness to IL-2, where Post (116.2%) and 4H (48.4%) was significantly greater in CHO (P < 0.05). NK, Th, and Tc were significantly higher Post (40.7, 102.7, and 82.0%, respectively) and lower at 2H (-51.9, -53.3, and -53.2%, respectively) than Pre (time effect). 4H was not different from Pre for NK, Th, and Tc. NKCA was significantly lower 2H (NKCA-51, NKCA-69) and 4H (NKCA-69) than Pre. CHO consumption during exercise did not prevent disruptions in unstimulated immune system function, but it did enhance NK responsiveness to IL-2.

Beta-phenylethylamines and the isoquinoline alkaloids

This review covers beta-phenylethylamines and isoquinoline alkaloids and compounds derived from them, including further products of oxidation, condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2001 to June 2002 is reviewed, with 581 references cited.

Exercise-induced change in type 1 cytokine-producing CD8+ T cells is related to a decrease in memory T cells

In response to exercise, both CD4(+) and CD8(+) T cells are mobilized to the blood, but the levels of these cells decline below preexercise values in the postexercise period. T cells are functionally polarized, depending on the cytokines they produce. Type 1 cells produce, e.g., interferon (INF)-gamma, whereas type 2 produce, e.g., interleukin (IL)-4. It was recently demonstrated that exercise induces a decrease in the percentage of type 1 T cells. The present study further investigated the mechanisms underlying the exercise-induced shift in the balance between type 1 and type 2 cytokine-producing cells. Seven healthy men performed 1.5 h of treadmill running with blood samples drawn before exercise, at the end of exercise, and 2 h after exercise. Intracellular expression of IFN-gamma, IL-2, and IL-4 was detected in CD4(+) and CD8(+) T cells after stimulation with phorbol 12-myristate 13-acetate and ionomycin. Intracellular expression of IFN-gamma within CD8(+) cells was decreased in the postexercise period compared with values obtained immediately after exercise, whereas the expression of IL-2 and IL-4 did not change within the CD4(+) and CD8(+) cell populations. The decrease in IFN-gamma-producing CD8(+) T cells postexercise was negatively correlated with a decrease in percentage of memory T cells within the CD8(+) cells (r = -0.94; P < or = 0.002). In conclusion, this study demonstrates that the exercise-induced change in type 1 cytokine-producing T cells is related to a decline in memory cells.