SOURCE:

Faculty: Health Sciences And Technology
Department: Medical Laboratory Science

CONTRIBUTORS:

Ehiaghie, F. A.
Onyenekwe, C. C.

ABSTRACT:

Stress regulates several genes in the human body but this varies with duration of stress. The duration of stress induced up-regulation or down- regulation of genes differs depending on the type of gene. The biochemical markers of stress such as blood levels of cortisol, glucose and progesterone are not stable. Therefore, expression of stress induced genes may be better alternative markers. Exercise-induced stress modulates immune responses. One of such intense exercise which is known as exhaustive exercise can be achieved through the use of Bruce thread mills protocol for sub-maximal exercise. Whereas the lymphocytic genes are considered as one of the best genes used to study the immunological changes associated with stress. The study was designed to use some lymphocytic genes to confirm evidence of stress in exercise exhausted apparently healthy young male undergraduates. The longitudinal study randomly selected twenty-five young apparently healthy students from Faculty of Health Sciences and Technology, Nnamdi Azikiwe University, Nnewi Campus, aged 24.3 ± 3 years. The participating male undergraduate students were placed under resting and relaxed conditions for 48 hours prior to the test. Their blood pressures and pulse rates were taken and fasting blood sugar determined as a prerequisite screening before enlisting in the protocol. The subjects took part in an endurance race using the Bruce treadmill protocol for sub-maximal exercise for a maximum of 21 minutes. The target heart rate on the treadmill was 60 – 80 percent of the heart rate reserve. Blood samples were collected from the participants before commencement of the study, at 1 hour, 4 hours and 24 hours post exercise. The blood samples were used for hormonal profiles (luteinizing hormone, follicle stimulating hormone, progesterone and cortisol), glucose, troponin I, creatine kinase MM using ELISA methods while the lymphocytes genes expression patterns were detected using reverse transcriptase polymerase chain reaction method. One-way ANOVA Post Hoc multiple comparisons and Student’s t-test were used for comparison of groups while Chi-Square test was used for of association using SPSS version 20.0. P values < 0.05 were considered significant. Lymphocytic succinate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and tumor necrosis factor α genes were up-regulated at 4 hours post exercise and sustained till 24 hours post exercise (X2 = 50, P = 0.000) respectively. However, there was an up-regulation of interleukin-10 genes and interferon gamma genes at 4 hours post exercise and sustained till 24 hours post exercise (X2 = 50, P = 0.000). Moreover, lymphocytic interferon gamma genes were expressed from 1 hour post exercise and sustained till 24 hours post exercise in five of the participants (X2 = 5.6, P = 0.000; X2 = 50, P = 0.000) respectively. There were significant variations between pre and post exercise Mean ± SD values of glucose (mg/dl) [F = 9.286, P = 0.000], cortisol (nmol/L) [F = 6.032, P = 0.000], progesterone nmol/L) [F = 2.351, P = 0.030] and luteinizing hormone (mIU/ml) [F = 9.153, P = 0.000]. These findings demonstrated that some lymphocytic genes such as succinate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and tumor necrosis factor α had early and stable gene expression patterns that lasted for 24-hours of investigation suggesting that these lymphocytic genes can be used as reference genes to confirm evidence of stress. Post-exercise stress activates the release of cortisol and interleukin-10 genes to reinstate homeostasis through modulation of the immune response.