Morphology and Ploidy of Smooth Muscle Cells in Chorionic Arteries under Different Hemodynamic Conditions.

Smooth muscle cells from the arterial wall of placental chorion were studied at 39-40-week gestation. The content of mono- and binuclear tetraploid myocytes was higher in sites of arterial branching and turns (27.3% vs.

Structural Organization of Arterial Vessels in Placental Hypoplasia.

Structure of the placental arterial bed was studied using histological and morphometric methods. The formation of smooth muscle regulatory complexes in blood vessels of the chorionic plate and chorionic villi was demonstrated. These complexes are genetically determined and represent a variant of compensatory and adaptive reorganization of the placental arteries for adequate fetoplacental blood supply under normal conditions and placental underdevelopment.

Polyploidy of smooth myocytes in coronary arteries.

Study of smooth myocytes in coronary arteries of dogs with experimental coarctation of the aorta revealed increased DNA content in myocyte nuclei and increased percentage of binucleated cells. Polyploidy of vascular myocytes did not disappear after correction of the aortal defect.

Regulatory structures of cerebral and renal arteries in experimental hyper- and hypotension.

Brain and kidneys from 15 control and 70 experimental puppies with hemodynamic model of coarctation of the aorta were examined. The number of regulatory muscle formations was increased in the brain and decreased in the kidneys during modeling of aorta coarctation associated with hyper- and hypotension in the corresponding basins. The location of these structures in cerebral and renal distribution and resistance vessels is analyzed.