Morphological Effects of Angiotensin in Arteries

Five to ten nanograms of labeled angiotensin II rapidly injected in the left ventricle of adult rats was found to induce significant ultrastructural endothelial changes, resulting in net increases in number and size of pinocytotic vesicles as well as widening of intercellular spaces. This effect was followed by preferential localization of the compound in the nuclear zone of vascular and cardiac muscle cells. The selective cellular localization of angiotensin II suggests that this vasoactive agent or some of its metabolic fragments may have specific effects on nuclear function.