Efeitos sobre o tecido ósseo e cartilagem articular provocados pela imobilização e remobilização em ratos Wistar

Effects of physical exercise on the cartilage of ovariectomized rats submitted to immobilization

Objective

To analyze the effects of physical exercise on cartilage histomorphometry in osteoporosis-induced rats subjected to immobilization.

Methods

We used 36 Wistar rats that were separated into six groups: G1, G2 and G3 submitted to pseudo-oophorectomy, and G4, G5 and G6 submitted to oophorectomy. After 60 days at rest, G2, G3, G5 and G6 had the right hind limbs immobilized for 15 days, followed by the same period in remobilization, being free in the box to G2 and G5, and climb ladder to G3 and G6. At the end of the experiment, the rats were euthanized, their tibias bilaterally removed and submitted to histological routine.

Results

There was significant increase in thickness of the articular cartilage (F(5;29)=13.88; p<0.0001) and epiphyseal plate (F(5;29)=14.72; p<0.0001) as the number of chondrocytes (F(5;29)=5.11; p=0.0021) in ovariectomized rats, immobilized and submitted to exercise. In the morphological analysis, degeneration of articular cartilage with subchondral bone exposure, loss of cellular organization, discontinuity of tidemark, presence of cracks and flocculation in ovariectomized, immobilized and free remobilization rats were found. In ovariectomized and immobilized remobilization ladder rats, signs of repair of the cartilaginous structures in the presence of clones, pannus, subcortical blood vessel invasion in the calcified zone, increasing the amount of isogenous groups and thickness of the calcified zone were observed.

Conclusion

Exercise climb ladder was effective in cartilaginous tissue recovery process damaged by immobilization, in model of osteoporosis by ovariectomy in rats.

Histomorphometric alterations of muscle soleus provoked by drawn out immobilization: experimental study with wistar lineage rats

Objective This study has as objective to analyze the effect of joint immobilization of the soleus muscle of posterior members of rats on morphometric profile view, at periods of 21 and 45 days. Materials and methods Ten male Rattus novergicus albinus, Wistar variety, were used, separated into two groups (group I and II), of 5 animals each, with the first group submitted to immobilization for 21 days and the second for 45 days. The experiment control was acquired from the right contralateral member of each animal. The immobilization of the left posterior member was done by adapted orthesis. The morphometric analysis of soleus was by non-serial cross sections, 8μm thick. Results From the obtained images, the muscle fibers areas were analyzed, including the form of the fibers, comparing with the control group. In both the periods of immobilization cross sections of staple fibres had reduction of the section area, front to the comparison to its respective member has controlled, with significant important (p < 0.0001), especially it enters the experimental groups of 21 and 45 days. Conclusion It can be concluded that immobilization to articulate of rats per 21 and 45 days modifies the section area more transversa of staple fibres of the sóleo muscle and deleterious effect of more significant the cellular components for drawn out periods.