Abstract
The acute entry of plasma proteins such as β-lipoprotein, fibrinogen and IgG into the subendothelial space of aorta has been shown to be induced by a single dose treatment of animals with cholesterol (1g/kg p. o.) or epinephrine (1μg/kg i. v.) or angiotensin II (1μg/kg i. v.) or bradykinin (10μg/kg i. v.). (Pros. Jap. Acad. 49: 336-341, 1972)
In order to see the route and mechanism for the transportation of such large particles from the vessel lumen to subendothelial space across the endothelial lining, the vital fixation of endothelial cells of the aorta was performed in animals challenged with the above mentioned substances.
In untreated or placebo control group of 10 animals, no pinch was found in the nuclei of 934 endothelial cells, while in animals challenged with cholesterol or epinephrine or angiotensin II or bradykinin, the appearance of nuclear pinches amounting 6.2±1.1% (P<0.001), 4.1±1.2% (P<0.01), 4.3±1.2% (P<0.01), 2.7±1.0% (P<0.01), respectively and the partial widening of intercellular junction were observed showing the contracting and swallowing activity of endothelial cells stimulated by the above mentioned substances. Blebs were found to be increased in such endothelial cells (P<0.05). In pretreated animals with Premarin (5mg/kg i. v.) or pyridinolcarbamate (10mg/kg p. o.), no nuclear pinch appeared by the same challenges.
In other groups of animals challenged by the above mentioned substances a marker such as ferritin (125Å) or carbon (Perikan ink 200-500Å) was given intravenously and 7 minutes to 3 hours thereafter the vital fixation was performed and a clear cut passage of ferritin and carbon was shown through the widened intercellular junction into the subendothelial space.
