[Proliferative activity of blood microvascular endothelium of intestinal mesentery during rat postnatal ontogenesis].

The study of mitotic activity of mesenteric microvascular endothelium cells (EC) in 4-, 12-, and 30-day old rats has been carried out using following parameters: number of labeled nuclei per vessel, or per 100 microm of vascular length, or per 1 mm2 of endothelial surface area, as well as shares of labeled EC and of vessels with labeled EC, have been estimated. The highest density of labeled nuclei was revealed in the pericapillary vessels in all rats. Its values were significantly higher in 12-day-old rats and were the lowest in 30-day-old ones.