[Morphometric study of the ultrastructural organization of the endotheliocytes of blood capillaries in the iliac lymph nodes of pregnant rats].

The ultrastructure of blood capillary endotheliocytes of iliac lymph nodes during pregnancy was investigated in rats. It was found that changes in microcirculation during pregnancy are accompanied by the appearance of the adaptive changes at all levels of lymph node structural organization. They are: increased lumen of arterial and venous part of the capillaries, increased intermediate sinus volume, increased fenestration of both parts of capillaries, a sharp increase in the number of micropinocytous vesicles and activation of transendothelial channel formation.