抄録
The constrictive effects of adrenaline or noradrenaline on large arteries (the thoracic aorta and carotid artery) were studied. Forty anesthetized male rabbits were used in this study. First group of animals were injected intravenously with adrenaline (0.1-10μg/kg) or infused with same solution (0.1-10μg/kg/min. for 10 minutes). Second group of animals were injected intravenously with noradrenaline (0.1-10μg/kg) or infused same solution (0.1-10μg/kg/min. for 10 minutes). All animals sacrificed intracardiac perfusion with 110mmHg of gultaraldehyde after 5-60 minutes. Electron microscopic specimens were taken with ordinary method.
1) Endothelial cells facing each other in the valleys squeezed in the madia through the fanestra of the internal elastic lamina. The attachment plate between an endothelial cell and a smooth muscle cell was often observed. The squeezing mechanism of the endothelial cell may be related inward movement of this attachment plate by the constrictive smooth muscle cell. Endothelial damages showed perinuclear vacuoles, myeline figures, whorls of surface membranes and the residual body containing the cytoplasm and myeline figures. The characteristic changes in the endothelial cell were the appearance of centrioles including neumerous endoplasmic reticulum or the extended Golgi apparatus. Platelets were occasionally adherent to this swoollen endothelial cell.
2) Typical edematous changes showing the extended extracellular space were observed in the squecimen followed by the injection of 30 minutes. These findings appeared as the initial stages in various arterial changes.
