[Structural changes in the lymph node sinuses in acute blood loss]

By means of light and scanning electron microscopy sinuses of the popliteal lymph nodes have been studied in 50 Wistar male rats. After modelling of an acute hemorrhage in the animals (in 15, 120 min and 1 day) volume of the medullary and marginal sinuses increases essentially, while blood stream intensity decreases in peripheral tissues. Amount of fenestrae in the sinusal lining decreases, that is, perhaps, caused by edema of cytoplasm in the lining cells and accompanied with formation of numerous cytoplasmic protrusions into the sinusal lumen. In 3 days the blood stream level in the peripheral tissues restores, structural organization of the littoral cells in the lymphatic sinuses normalizes. The data obtained demonstrate that during the first day after the acute hemorrhage decrease of hematolymphatic exchange intensity in lymph nodes and enhancement of transitory lymph flow in them take place.