Voluntary training in mice and submandibular lymphocyte response to acute exercise.
ABSTRACT Submandibular lymph nodes (SLN) are important for immune responses to antigens in the eye and oral mucosa. Athletes and exercise participants may be at increased risk of ocular, oral, and upper respiratory tract infections.
This study was conducted to examine the effects of voluntary training on the distribution, number, and apoptotic status of SLN lymphocytes in response to an acute bout of strenuous exercise.
Female C57BL/6 mice were assigned to voluntary wheel-running (WR) exercise (N=20) or were sedentary (N=10) for 16 wk. SLN lymphocytes were examined immediately (EX+Imm) or 24 h (EX+24 h) following strenuous treadmill exercise, or exposure to treadmill conditions without running (NonEX). Intracellular glutathione (GSH), mitochondrial membrane potential (MMP), cell viability (propidium iodide uptake, PI), surface phosphatidylserine (Annexin V), T-lymphocyte (CD3, CD4, CD8), and B-lymphocyte (CD19) phenotype distribution and number were assessed.
The WR mice had a higher number and percent CD8 SLN lymphocytes, higher MMP, and lower Annexin V/PI SLN lymphocytes than controls. Regardless of training status, an acute bout of strenuous exercise decreased the total and phenotype specific (CD3, CD4, CD8) number of cells, MMP, and GSH levels immediately after exercise.
WR in mice improved some aspects of cell viability in SLN lymphocytes compared with controls, but did not prevent the transient cell loss after acute treadmill exercise. Given the depletion in intracellular GSH levels, oxidative stress may account for the decline in SLN lymphocyte numbers following acute exercise. Loss of SLN lymphocytes may have consequences for ocular, oral, and upper respiratory tract health in some exercise participants and athletes during periods of overtraining.
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ABSTRACT: Submandibular lymph nodes (SLN) are crucial for immune surveillance of the anterior ocular chamber and upper respiratory tract; little is known about how training and exercise affect SLN lymphocytes. The intent of this study was to describe the impact of long term freewheel running followed by acute strenuous exercise on SLN lymphocytes in mice. Female C57BL/6 mice were assigned to running wheels or remained sedentary for 8 months, and further randomized to treadmill exercise and sacrifice immediately, treadmill exercise and sacrifice 24 h after exercise cessation, or no treadmill exposure. SLN lymphocytes were isolated and analyzed for CD3, CD4, CD8, and CD19 cell surface markers, phosphatidylserine externalization as a marker of apoptosis, and intracellular glutathione as a marker of oxidative stress. Compared with running wheel mice, older sedentary mice had a lower percent of T cells and higher percent of B cells (p < 0.05). Although intracellular glutathione did not differ between groups, running mice had a lower percent of Annexin V(+) SLN lymphocytes 24 h after treadmill exercise. Further research will be needed to determine if voluntary exercise translates into improved anterior ocular and upper respiratory tract health.Canadian Journal of Physiology and Pharmacology 05/2006; 84(5):565-72. · 1.56 Impact Factor
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ABSTRACT: Intestinal homeostasis effectors, secretory IgA (SIgA) and polymeric immunoglobulin receptor (pIgR), have been evaluated in proximal and distal small intestine with moderate-exercise training but not with strenuous exercise or a combination of these two protocols. Therefore, two groups of mice (n=6-8) were submitted to strenuous exercise, one with and one without previous training. The control group had no exercise protocol. Assessment was made of intestinal SIgA and plasma adrenal hormones (by immunoenzymatic assay), alpha-chain and pIgR proteins in intestinal mucosa (by Western blot), lamina propria IgA plasma-cells (by cytofluorometry), mRNA expression (by real-time PCR) for pIgR, alpha- and J-chains in liver and intestinal mucosa, and pro- and anti-inflammatory cytokines in mucosa samples. Compared to other exercise protocols, training plus strenuous exercise elicited: (1) higher levels of SIgA and pIgR in the proximal intestine (probably by hepatobiliary contribution); (2) higher levels of SIgA in the distal segment; (3) lower mRNA expression of some SIgA- and most pro-inflammatory pIgR-producing cytokines. SIgA and pIgR in both segments were derived from an existing pool of their corresponding producing cells. The apparent decreased translation of mRNA transcripts underlies lower levels of SIgA and pIgR in distal than proximal small intestine. There was no significant difference in the relatively high adrenal hormone levels found in both exercised groups. Further study is required about the effects of training plus strenuous exercise on pool-derived SIgA levels and mRNA expression of pro-inflammatory pIgR-producing cytokines. These results could have important implications for intestinal disorders involving inflammation and infection.Brain Behavior and Immunity 08/2012; 26(8):1300-9. · 5.61 Impact Factor