| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
Morphological changes in the shear stress (blood flow) loaded artery were studied using arterio-venous shunt method following Kamiya and Togawa (Am J phyiol 239:14-21,1980). We used arterio-venous anastomosis between the common carotied artery and the external jugular vein in adult female beagel dogs and rats and observed the proximal portion of the common carotid artery from the anastomosis where blood flow rate was increased. In dogs, endothelial cells showed the protrusion of nucleic parts, appearance of microvilli, disturbance of pinocytotoc vesicles and increased cytoplasmic microfilament bundles (actin filament stress fibers) as early as 1 week. They increased in density (6,000 cells/mmxmm)(3,000 cells/mmxmm at the contralateral common carotid artery) in 4 weeks. They were slender but thick. Their nuclei were prolate spheroid in shape and as big as those of the contralateral control which were oblate spheroid in shape. Bsement membrane of the endothelial cells was thick as early as 1 week. Internal elastic lamina was splitted and multiplicated in 4 weeks. Media showed distinct increase of elastic fiber and elastic lamina in 6 to 12 months. To disclose the process of increase of endothelial cells in 4 weeks, we used bromodeoxyuridine (BrdU). With application of monoclonal antibody to BrdU, we found BrdU incroporation into the endothelial cell nuclei. In rats, almost same endothelial cell changes could be observed in the flow loaded carotid arteries. They increased in dencity (7,000 cells/mmxmm) in 2 to 4 weeks (3,000 cells/mmxmm in contralateral common carotid artery). From this study, it is clear that endothelial cells change actively under the loadance of shear stress (blood flow) and arterial wall changes in chronic stage. It should be important to study vascular research, such as the study of atherogenesis, with a thought that vascular is under the control of shear stress (blood flow).
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