The effect of strenuous exercise on mRNA concentrations of interleukin-12, interferon-gamma and interleukin-4 in equine pulmonary and peripheral blood mononuclear cells.

This study looks at the influence of heavy exercise on the concentrations of specific molecules, namely interleukin-12p35, interferon-gamma and interleukin-4, in the lungs and peripheral blood cells of horses. The research suggests that high levels of physical activity does not negatively affect the expression of these particular molecules, contradicting the initial hypothesis.

Research Methodology

• Eleven horses were the subject of this study and were randomly divided into two groups: a control group that was confined to stables (5 horses), and a treatment group subjected to exercise conditioning (6 horses).
• Cells were obtained from two sources: bronchoalveolar cells, which are found in the airways of the lungs, and peripheral blood mononucleated cells (PBMCs), a type of white blood cell important to the immune system.
• For the horses undergoing the exercise regimen, samples were taken before the start of a 9-week long conditioning program and 24 hours after completion of a maximum exercise test conducted in week 12. The control group’s samples were taken at the same time to ensure the conditions were consistent.

Sampling Process

• Differential counts were performed on bronchoalveolar lavage cells. This technique is used to differential count the different types of white cells and can provide valuable information about the immune response.
• Real-time PCR (polymerase chain reaction) technology, coupled with equine-specific primers and Taqman probes, quantified cytokine expression in the cells. TaqMan probes are a common method used to amplify and detect DNA molecules.
• Expression of target genes was normalized to 18s rRNA expression. This technique makes it possible to ensure the results apply broadly across the different samples and horses.

Research Results

• Except for IL-4 in the bronchoalveolar lavage fluid cells, mRNA for the three examined cytokines was detected in the mononuclear cells from all horses and at both sampling times.
• No significant differences in the concentrations of cytokine mRNA were observed between the control and exercise-conditioned groups at either sampling time.
• These results indicate that strenuous physical activity, such as treadmill exercise, does not detrimentally affect gene expression for IL-12p35, IFN-gamma or IL-4, when measured in horses 24 hours after the exercise.