[Endothelial cell nucleoli during regeneration after injuries inflicted at different times of the day].

Quantitative changes in the state of the nucleolar apparatus of endothelial cells in the rabbit jugular veins were studied at regeneration after trauma produced either at 8-10 a.m. or at 8-10 p.m. The animals were killed every 3 h after the operation during 5 days. The nucleolar apparatus was studied continuously at the distance of 12.8 mm along the edge of the defect in flat film preparations. The data obtained were treated by methods of variational statistics. In endothelium, the number of cells with greater than normal amount of nucleoli increases under the conditions of post-traumatic regeneration. It is connected with activation of synthesis which has a wavy character in time and space. All quantitative estimations presented demonstrate a dependent character of the changes in the number of nucleoli on the time of the operation. The p. m. operation results in intensified endothelial synthetic activity with a shorter time for reaching its maximum.