[Microcirculatory bed and the structure of the compact substance of the cat tibial diaphysis normally and after multiple exposure to G loads]. / Mikrotsirkuliatornoe ruslo i stroenie kompaktnogo veshchestva diafiza bol'shebertsovoi kosti koshki v norme i posle mnogokratnogo vozdeistviia gravitatsionnykh peregruzok.

Blood bed and structure of the compact substance of the cat tibial diaphysis have been studied at normal conditions and after repeated effect of gravitational overloadings. Hypergravitation produced a noticeable rearrangement in the microcirculatory bed and in histoarchitectonics of the bone compact substance. The date obtained demonstrate that the changes produced depend on the number of parameters participating in the gravitational effect and on the position of the animal in the container, as well as on the time when the animal falls ill after the experiment.

[Changes in the microcirculatory bed of the compact substance of bones following local mechanical pressure, gravitational stress and hypokinesia]. / Izmeneniia mikrotsirkuliatornogo rusla kompaktnogo veshchestva kostei pri mestnom mekhanicheskom davlenii, gravitatsionnykh peregruzkakh i gipokinezii

Effects of different stimuli upon the structure of the microcirculatory bed of the compact substance of long tubular bones were studied in 89 animals (rabbits and cats). Prolonged local pressure on the bone resulted in transformations characterized by lacunar resorption of the compact substance in the site of application of the force and endosteal bone-formation on the opposite side of the same part of the bone. Hypergravitation caused a considerable transformation of the microcirculatory bed and the histoarchitectonics of the bone compact substance. Smooth and linear perivascular resorption took place around dilated vessels in osteon canals. It resulted information of resorption cavities. In addition, processes of bone formation took place. Due to effects of hypokinesia the transformation of the compact substance is of a regressive character. The fibrous structures of the bony tissue and blood vessels lose their regular orientation and acquire chaotic direction.