| Abstract: | ![]()
An infarct of the myocardium of the left ventricle was produced in adult rats weighing 120–160 g by ligating the left coronary artery at different levels: in the atrial region, at the level of the first third of the left ventricle, and in its middle. In other series of experiments the left atrium was damaged by applying a ligature to its anterior wall or to the auricle. Animals undergoing a mock operation during which the pericardium was removed acted as the control. The left half of the heart was investigated on the 5th day after the operation. Mitotically dividing myocytes were found in the atrium or auricle of the animals in those series of experiments in which these parts of the heart had been directly injured and had a thickened epicardium (in 35 of 49 cases); the mitotic index varied from 0.9 to 10%. After litigation of the coronary artery in the middle of the ventricle mitoses were not found in the myocytes of the atrium and auricle. In all series of experiments mitoses were rare in the myocytes of the ventricle (in seven of 49 cases) and were located at a distance from the infarct, in subepicardial zone; the mitotic index there varied from 1 to 2%.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 998–1002, August, 1976. |
