Combined Effect of Physical Activity and Epiphysectomy on Blood Coagulation in Rats

Purpose: Many investigations indicate the direct and indirect effects of pineal gland on coagulation system particularly on thrombin time. It is well known that exhaustive exercise alters blood coagulation and fibrinolysis, but the assessment of the dimension and importance of these changes is difficult. This study was designed to determine the effect of physical activity interaction epiphysectomy with on coagulation system in rats.Methods: Sixty healthy male rats 30 days old were selected. They were divided into experimental and control groups. Epiphysectomy was performed on experimental animals. Coagulation time and thrombin time were measured on each subgroup (control, short-time physical activity and long-time physical activity). Results: There was a significant difference between experimental and control groups before and after epiphysectomy (P<0.001). Physical activity decreased thrombin time on different tissues of rats. Conclusions: Our results suggested effect of physical activity on thrombin time and coagulation time and also the role of pineal gland on thrombin time in rats. Key word: Physical activity; Pineal gland; Thrombin time; Coagulation time; Rat INTRODUCTION The pineal gland (epiphysis) synthesizes and secretes melatonin, a structurally simple hormone that communicates information about environmental lighting to various parts of body. Ultimately, melatonin has the ability to entrain biological rhythms and has important effects on physiological function on many animals. Numbers of investigations indicate the direct and indirect effects of melatonin on coagulation system (1-3). Pinotti, et al in their studies concluded that the chronobiological patterns should consider analyzing activity levels of coagulation factors (4). According to the results of another study, exogenously administered melatonin reduces skin oxidant damage and normalizes the activated blood coagulation induced by thermal trauma (3). It is known that physical activity induces modification in blood hemostasis and leads to ______________________________ *Correspondence to: R. Hossein Tel : +989144149256 E-Mail: [email protected] Running Head: physical activity and pineal gland on thrombin time an activation of blood coagulation and fibrinolysis (5). Physical stress is associated with the activation of blood cell (6). Several studies have shown that strenuous exercise leads to a shortening of the activated partial thromboplastin time and results in an increase of thrombin generation markers (7). It is well known that exhaustive exercise alters blood coagulation and fibrinolysis (8). But the assessment of the dimension and importance of these changes is difficult. Long-term physical exercise is known to promote changes in the coagulatory and fibrinolytic activities of the blood. In contrast, changes in the procoagulatory components of the hemostasis remain rather poorly understood and studies on the effects of exercise on the anticoagulatory system are few (9). Few studies exist on the relationship between the clotting times and exercise. The increase in clotting and fibrinolytic activity due to exercise has been widely documented in human and experimental animals (10).In this study we considered effect of physical activity