Characterization of mitochondria isolated from normal and ischemic hearts in rats utilizing atomic force microscopy.
Mitochondria play critical roles in both the life and the death of cardiac myocytes. Various factors, such as the loss of ATP synthesis and increase of ATP hydrolysis, impairment in ionic homeostasis, formation of reactive oxygen species (ROS), and release of proapoptotic proteins are related to the generation of irreversible damage. It has been proposed that the release of cytochrome c is caused by a swelling of the mitochondrial matrix triggered by the apoptotic stimuli. However, there is a controversy about whether or not the mitochondria, indeed, swell during apoptosis. The major advantages of atomic force microscopy (AFM) over conventional optical and electron microscopes for bio-imaging include the fact that no special coating and vacuum are required and imaging can be done in all environments--air, vacuum or aqueous conditions. In addition, AFM force-distance curve measurements have become a fundamental tool in the fields of surface chemistry, biochemistry, and material science. In this study, we used AFM to observe the morphological and property changes in heart mitochondria that were isolated from a rat myocardial infarction model. From the shape parameters of the mitochondria in the AFM topographic image, it seemed that myocardial infarction caused the mitochondrial swelling. Also, the results of force-distance measurements showed that the adhesion force of heart mitochondria was significantly decreased by myocardial in infarction. Therefore, we suggested that myocardial infarction might be the cause of mitochondrial swelling and the changes in outer membrane of heart mitochondria.
Department of Biomedical Engineering, College of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.
Gi-Ja
GJ
Lee
Su-Jin
SJ
Chae
Jae Hoon
JH
Jeong
So-Ra
SR
Lee
Sang-Jin
SJ
Ha
Youngmi Kim
YK
Pak
Weon
W
Kim
Hun-Kuk
HK
Park
D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D018625:Microscopy, Atomic Force; D008929:Mitochondria, Heart / Q000737:chemistry* / Q000473:pathology; D009203:Myocardial Infarction / Q000473:pathology*; D051381:Rats