THE INFLUENCE OF STENOSIS OF AORTOILIAC SEGMENT ON ULTRASTRUCTURAL ORGANIZATION OF HEMOCAPILLARIES OF THE MAIN BRAIN IN RATS

Abstract

Changing the nature of central hemodynamics can both precede and complicate the course of acute ischemic lesion of the brain. Moreover, cardiovascular disorders, leading to the development of acute ischemic lesion of the brain, make up about 30–40 % in the structure of all pathogenetic variants.

The aim of the study – to determine the peculiarities of ultrastructural changes in the capillaries walls of rats brain after aortoiliac segment stenosis.

Materials and Methods. Experiments were carried out on 18 sexually mature white laboratory male rats weighing 160–180 g. Among them 3 animals were in the control group. The other 15 rats were under ketamine anesthesia constricted the aorta stenosis directly over its bifurcation by 2/3 of a diameter. The material for electron microscopic studies was taken after 1, 3, 7, 14 and 28 days after surgery in accordance with the generally accepted method.

Results and Discussion. The conducted electron microscopic study of structural components of the cerebral cortex of the rats brain after the experimental stenosis of the caudal part of the abdominal aorta leads to the stage of morphofunctional and remodeling changes of the microcirculatory flow in the dynamics of which the following periods can be distinguished:

– alterations (edema of the endothelial cell cytoplasm with simultaneous destructive organelle changes, uneven thickening of the basal membrane and perivascular spaces extension) – immediately after stenosis and before the 3rd day of observation;

– adaptive-compensatory changes – from the 3rd to the 7th day of the experiment with the stabilization of the morphofunctional state of the microcirculatory flow (reduction of edema of the endothelial cell cytoplasm, more stable organelles state, clear contours of the basal membrane);

– restorations – from the 14th to the 28th day of observation with the backward development of alterational changes and significant, but not complete, restoration of the initial state of structural components of the brain hemocapillary walls.

Conclusions. Morphofunctional remodeling of the rats cerebral cortex structural components after the experimental stenosis of the caudal part of the abdominal aorta caused changes according the following periods: alterations – immediately after stenosis and before the 3rd day of observation; compensation – from the 3rd to the 7th day of the experiment and partial restoration in more distant terms.