论文部分内容阅读
Objective: This study investigated apoptosis occurred in cardiac muscle after different intensity of exhaustive exercises, as well as the role of free radical and mitochondria uptake calcium in myocardial apoptosis.Methods: Thirty male adult Sprague-Dawley rats are randomly divided into three groups: control(C, n=l0), middle intensity exhaustive exercise(ME,n=10) and high intensity exhaustive exercise(HE, n=10).The rats of ME and HE group run on the treadmill to exhaust with the speed of 19.3 m/min(76% Vo2max) and 26.8 m/min (92.3% VO2max) respectively.SOD activity and MDA content in tissue homogenate and the mitochondrial Ca2+content are examined, Paraffin wax sections labeled by TUNEL, the apoptotic myocardial nucleolus detected by microscope and the change of myocardial nucleolus 、 mitochondrion ultrastructure examined under electron microscope.Results: (1) Fewer TUNEL positive in the cardiac muscle is detected in the control group.Myocardial apoptosis index in exhaustive exercise groups were significantly different from that in the control group (p<0.05) . The number of myocardial apoptosis in middle intensive exercise group (9.73±2.09)were significantly higher than those in the control (0.37±0.21) and high intensive exercise group (6.67±1.60) (p<0.05).(2) Apoptosis nucleolus displays an irregular shape and a highly condensed chromatin along the inner surface of the nuclear envelope in the electron microscope examine.Exercise groups mitochondrion bulge and configurable is not clear.(3) ME group and HE groups SOD activity decreased about 67% and 48% than control group respectively (p<0.05).(4) MDA content of ME group and HE group are both increased significantly but the difference were not significant.(5)Megroup and HE groups mitochondrial Ca2+ in myocardial tissue were separately increased about 92% and 66% than the control group respectively (p<0.05).But the comparison of that exercise groups have no significance.Conclusion: Acute exhaustive exercise can lead to cardiac muscle apoptosis, the middle intensive exhaustive exercise more prone to cause apoptosis.There are possible correlate with the exhaustive exercise duration.The possible mechanism of myocardial apoptosis is the great accumulation of Ca2+ in mitochondrion trigger the apoptosis program.