Exercise is a physical activity that is utilized to improve health, maintain fitness and it is important as a means of physical rehabilitation. Physical exercise is important for strengthening the immune system. The immune responses to exercise are dependent on the intensity and duration of the exercise performed. During exercise, metabolic and hormonal changes occure that can induce lymphocyte apoptosis.
Apoptosis is a physiological type of cell death; its active, well-controlled genetic program of cell death that does not require the participation of the inflammatory process. It is responsible for focal elimination of unwanted cells during normal embryonic development, organ homeostasis, immune regulation and defense without causing stress to the neighboring cells. Melatonin it is a pineal gland hormone, its production and secretion followed a circadian pattern, oncet of darkness stimulate its secretion, while day light suppress its production. Dehydroepiandrostenidone sulphate (DHEAS) it is an androgenic steroidal hormone its synthesis and secretion under the effect of adrenocortiocotropin releasing hormone (ACTH).
Melatonin and DHEAS regarded as anti-aging hormones; they had a role in the elimination of harmful lymphocytes which may give rise to chronic inflammation and possibly to autoimmunity. The aim of this study was to elucidate the effect of moderate exercise on melatonin, DHEAS hormones and the percentage of peripheral blood lymphocyte apoptosis in healthy subjects of different age groups. Sixty healthy subjects with a mean age of (37.05 ± 13.02) year, participated in the study. They were subjected to moderate exercise session which lasted for 60 min and repeated 3 times per week for 3 months. The exercise intensity was 50-60% of heart rate reserve (according to Karvonen formula). Two exercise stages were performed; the first stage include 30 minute of physical activity program and the second stage include 30 minute of treadmill exercise.The pulse rate, systolic and diastolic blood pressure was measured. Blood sample were collected before and after exercise to examine its effect on the level of melatonin and DHEAS hormones and apoptosis of peripheral blood lymphocyte by using acridine orange dye. The results showed that the pulse rate was significantly increased P < 0.05 after exercise along the three months.The systolic blood pressure was significantly increased (P <0.05) after exercise from the first week to the seventh week, but not then after eighth week to the end of experiment. The diastolic blood pressure was significantly elevated (P < 0.05) after exercise from the first week to the eighth week but not then after ninth week to the end of experiment. This study showed significant increment (P < 0.05) in the level of melatonin and DHEAS hormones and the percentage of lymphocyte apoptosis after exercise in comparison to pre exercise values for each week along the period of the test. Three months exercise showed a significant correlation with the levels of melatonin hormone (P= 0.008, r= 0.44), and with DHEAS hormone level (P= 0.000, r= 0.75), and so on with percentage of lymphocyte apoptosis (P = 0.001, r= 0.701). From all of these observations, it can be concluded that moderate exercise for three months was associated with: - Increased the percentage of periphral blood lymphocyte apoptosis. - Increased level of melatonin and DHEAS hormones in the first two months while in the third month these anti aging hormones had reached to a steady state after the subjects get trained to exercise.