CAPILLARY NETWORK OF THE ADENOGYPOPHISIS IN THE NORM AND UNDER CONDITIONS OF GRAVITATIONAL STRESS
The study of the state of the body's regulatory systems under the influence of various exogenous factors is one of the most important tasks of functional morphology. In all the variety of external influences that affect a person, hypergravity occupies a special place. This article discusses the bloodstream of the adenohypophysis in normal conditions and during modeling of acute and chronic gravitational stress. As experimental animals, 30 outbred rats were selected, divided into experimental and control groups (21 and 9 animals). Simulation of overloads was carried out by rotating animals on a centrifuge with a shoulder radius of 1,5 m. The experiment consisted of 3 series of experiments: acute (AGS) and 2 chronic (CGS) for 13 and 26 weeks. Normally, in intact rats, a significant number of capillaries of the gland are in a collapsed state, but the lumen of other capillaries is quite wide; it contains, as a rule, single blood cells. The capillary wall includes fenestrated type endotheliocytes. After acute exposure to hypergravity, the area occupied by the capillaries of the gland was increased by 3,5 times compared with the control and amounted to 26.9±1.9 mm<sup>2</sup>. The lumen of the capillaries that fell into the field of vision was enlarged and filled with blood cells. After exposure to overloads for 13 weeks (II series), the area occupied by the vessels of the gland was increased by 6,1 times compared with the control and amounted to 32.4±2.4 mm<sup>2</sup>. It was noted the expansion of intercellular gaps and increased processes of exocytosis. Pronounced changes in the hemomicrocirculatory bed were noted in series III. For the first time during the experiment, ultrastructural manifestations of destruction of the endotheliocyte cytolemma were found, due to a decrease in their resistance to the effects of overloads. Since such changes develop in the course of the systematic action of hypergravity, they should be considered cumulative [5].