Forced exercise changes catecholamine synthesis in the spleen of adult rats

Exercise-induced adaptive response of different immune organs during ageing

The immune system plays a crucial role in the ageing process. As individuals age, significant alterations in the immune system experiences occur, marked by a decline in immune cell count, compromised immune function, and decreased immune regulation across various immune organs. These changes collectively weaken the capacity to combat diseases and infections, highlighting the vulnerability that accompanies ageing. Exercise is a potent intervention that profoundly influences holistic well-being and disease mitigation, with a notable emphasis on immune modulation. In general, regular moderate exercise holds significant potential to enhance immune defense mechanisms and metabolic well-being by augmenting the circulation and activation of immune cells. However, some exercise modalities would trigger detrimental effects on the immune system. It can be seen that the regulatory responses of various immune organs to diverse exercise patterns are different. This review aims to examine the immunological responses elicited by exercise across various immune organs, including the lymph nodes, spleen, bone marrow, and thymus, to underscore the nuanced interplay between exercise patterns and the immune organ. This underscores the importance of customizing exercise interventions to optimize immune function across the lifespan.

Antioxidant defense system in the prefrontal cortex of chronically stressed rats treated with lithium

Background

This study aimed to investigate the effects of lithium treatment on gene expression and activity of the prefrontal antioxidant enzymes: copper, zinc superoxide dismutase (SOD1), manganes superoxide dismutase (SOD2), catalase (CAT), and glutathione peroxidase (GPx) in animals exposed to chronic restraint stress (CRS).

Methods

The investigated parameters were quantified using real-time RT-PCR, Western blot analyses, and assays of enzyme activities.

Results

We found that lithium treatment decreased gene expression of SOD2, as well as the activities of SOD1 and SOD2 in chronically stressed rats to the levels found in unstressed animals. However, lithium treatment in animals exposed to CRS increased prefrontal GPx activity to the levels found in unstressed animals.

Conclusions

These findings confirm that treatment with lithium induced the modulation of prefrontal antioxidant status in chronically stressed rats. Our results may be very important in biomedical research for understanding the role of lithium in maintaining the stability of prefrontal antioxidant defense system in neuropsychiatric disorders caused by chronic stress.

The immunological influence of physical exercise on TBI-induced pathophysiology: Crosstalk between the spleen, gut, and brain

Traumatic brain injury (TBI) is a non-degenerative and non-congenital insult to the brain and is recognized as a global public health problem, with a high incidence of neurological disorders. Despite the causal relationship not being entirely known, it has been suggested that multiorgan inflammatory response involving the autonomic nervous system and the spleen-gut brain axis dysfunction exacerbate the TBI pathogenesis in the brain. Thus, applying new therapeutic tools, such as physical exercise, have been described in the literature to act on the immune modulation induced by brain injuries. However, there are caveats to consider when interpreting the effects of physical exercise on this neurological injury. Given the above, this review will highlight the main findings of the literature involving peripheral immune responses in TBI-induced neurological damage and how changes in the cellular metabolism of the spleen-gut brain axis elicited by different protocols of physical exercise alter the pathophysiology induced by this neurological injury.

Stressors affect urocortin 1 and urocortin 2 gene expression in rat spleen: The role of glucocorticoids

The mechanisms underlying stress-related modulation of immune function via urocortin 1 and urocortin 2 have been only vaguely described. Therefore, we investigated the effect of LPS injection or immobilization stress on gene expression of urocortin 1 and urocortin 2 in the rat spleen, along with the potential involvement of glucocorticoids. Our data showed: a) different regulation of urocortin 1 and urocortin 2 gene expression in the rat spleen under different stressful conditions (LPS vs. immobilization stress) and b) diverse effects of stress-induced adrenal glucocorticoids on this process. Our findings indicate a specific, rather than general regulation of splenic immune function by urocortins during stressful conditions.

Modulation of Hippocampal Antioxidant Defense System in Chronically Stressed Rats by Lithium

This study examined the effects of lithium on gene expression and activity of the antioxidant enzymes copper zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) in the hippocampus of chronically stressed rats. In addition, we examined the effects of lithium on anxiety behaviors, hippocampal concentrations of dopamine (DA) and malondialdehyde (MDA), protein levels of brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH), dopamine transporter (DAT), and catechol-O-methyltransferase (COMT), as well as activity of monoamine oxidase (MAO) in chronically stressed rats. The investigated parameters were quantified by real-time RT-PCR, Western blot analyses, and assays of enzyme activities. We found that lithium did not change gene expression of SOD1, CAT, GPx, and GR but decreased gene expression of SOD2 in chronically stressed rats. A very important result in this study was that lithium treatment decreased the enzyme activities of SOD1 and SOD2 but increased the enzyme activities of GPx and GR in stress condition, which indicates the control of redox balance. The reduced concentration of MDA confirms this. In addition, we found that lithium treatment decreased high protein levels of BDNF and DAT in chronically stressed rats to the level found in unstressed animals. Also, lithium treatment increased the expression of TH but decreased the enzyme activity of MAO B, which contributed to the increase of hippocampal concentration of DA in chronically stressed rats to the level of unstressed animals. Finally, lithium treatment in animals exposed to chronic stress increased the time spent in open arms. Lithium-induced modulation of hippocampal antioxidant status and attenuation of oxidative stress stabilized behavior in animals with high anxiety index. In addition, reduced oxidative stress was followed by the changes of both turnover of DA and levels of BDNF protein in chronically stressed rats treated with lithium. These findings may be important in preclinical research of the effects of lithium on oxidative stress level in pathological conditions.

Increased Activity of Hippocampal Antioxidant Enzymes as an Important Adaptive Phenomenon of the Antioxidant Defense System in Chronically Stressed Rats

This study examined the effects of chronic restraint stress (CRS: 2 hours × 14 days) on gene expression of three antioxidant enzymes, copper, zinc superoxide dismutase (SOD 1), manganese superoxide dismutase (SOD 2) and catalase (CAT) in the rat hippocampus. Also, we examined changes in the activities of SOD 1, SOD 2 and CAT in the hippocampus of chronically stressed rats. Investigated parameters were quantifi ed by using real-time RT-PCR, Western blot analysis and assay of enzymatic activity. We found that CRS did not change mRNA and protein levels of SOD 1 and CAT, but increased mRNA and protein levels of SOD 2. However, CRS treatment increased the enzyme activities of SOD 1, SOD 2 and CAT. Our fi ndings indicate that the increased activity of antioxidant enzymes (SOD 1, SOD 2 and CAT) in the hippocampus may be an important adaptive phenomenon of the antioxidant defense system in chronically stressed rats.

Inverse effects of midlife occupational and leisure time physical activity on mobility limitation in old age--a 28-year prospective follow-up study

OBJECTIVES

To evaluate in a sample of initially middle-aged municipal employees whether leisure time (LPA) or occupational physical activity (OPA) was associated with mobility limitation (ML) in old age.

DESIGN

Prospective population-based follow-up.

SETTING

Municipalities in Finland.

PARTICIPANTS

Public sector employees from the Finnish Longitudinal Study on Municipal Employees (FLAME) initially aged 44 to 58 (N = 5,200).

MEASUREMENTS

Baseline data were collected in 1981, including LPA (average exercise within previous year: inactive (no exercise), moderate (some form of exercise ≤ 1 time per week), vigorous (brisk exercise ≥ 1 time per week)) and OPA (usual activities at work within previous year: light (light work sitting, standing, or moving around), moderate (moderate work moving around), vigorous (heavy physical work)). Number of MLs was assessed using a questionnaire (8 items) in 1985, 1992, 1997, and 2009; the latest mobility score available for each subject was used for analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for LPA and OPA predicting ML were estimated in a joint Poisson regression model adjusted for survival data; the other type of PA; and sociodemographic, socioeconomic, and health-related factors.

RESULTS

Mean age at baseline was 50.3 ± 3.6; 56.9% of participants were female. Participants with vigorous OPA in midlife had greater risk of a unit increase in ML in old age than those with light OPA (fully adjusted IRR = 1.09, 95% CI = 1.03-1.16). Participants with vigorous LPA had lower risk of ML than inactive participants (fully adjusted IRR = 0.81, 95% CI = 0.76-0.86).

CONCLUSION

Findings suggest that LPA and OPA in midlife have independent, inverse effects on mobility in old age in terms of a harmful effect of vigorous OPA and a protective effect of vigorous LPA.