Análise biomecânica dos efeitos da crioterapia no tratamento da lesão muscular aguda

Effects of long-term administration of omeprazole on bone mineral density and the mechanical properties of the bone

OBJECTIVES

Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD) of rats that were subjected to long-term omeprazole use.

METHODS

Fifty Wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 μmoL/kg/day); OMP200 (200 μmoL/kg/day); OMP40 (40 μmoL/kg/day); OMP10 (10 μmoL/kg/day); and Cont (control group; intake of dilution vehicle). The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed.

RESULTS

The BMD of the OMP300 group was lower than that of the controls (p = 0.006). There was no difference on comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049), but the other groups did not show any difference in relation to the controls.

CONCLUSION

Daily intake of 300 μmoL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats.

Supplement with Cystoseira canariensis promotes an increase of resistance to the maximum load in the grastrocnemius muscle of female rats

Was evaluated the maximum load supported by the grastrocnemius muscle of female rats after the ministering of Cystoseira canariensis, either associated or not to swimming. Twenty-eight young Wistar female rats were used, divided into 4 groups: control (C, n=7); supplement (S, n=7); supplement and swimming (SSw, n=7); swimming (Sw, n=7). Each one pertaining to the groups S and SSw received 20 mg of myostatin inhibitor per day. The swimming consisted in an aerobe protocol, three times in a week, during eight weeks. The right grastrocnemius muscle of each animal was removed and a tension test was performed in an Emic testing machine. The results (Mean±SEM) were evaluated through ANOVA and Tukey test (p<0.05). A significant difference for maximum load (in N) was verified among the groups C (35.41±1.06) and S (39.98±1.15); Sw (27.94±2.19) and S (39.98±1.15); Sw (27.94±2.19) and SSw (37.78±1.28). In relation to the stretching at the maximum limit (in x10-3m) at the maximum load, the group SSw obtained a value (20.68±1.19) significantly greater than the groups C (17.15±1.11), S and Sw (16.11±1.60). There was a significant difference for body weight gain among the groups treated with supplement and supplement associated to the swimming, with smaller values for this last. The myostatin inhibitor either, associated or not to the swimming, promotes an increase of resistance to the maximum load in the tension test in grastrocnemius muscle of young female rats.

Muscle mechanical properties of adult and older rats submitted to exercise after immobilization

Objectives

To describe the effects of immobilization, free remobilization and remobilization by physical exercise about mechanical properties of skeletal muscle of rats of two age groups.

Methods

56 Wistar rats divided into two groups according to age, an adult group (five months) and an older group (15 months). These groups were subdivided in: control, immobilized, free remobilized and remobilized by physical exercise. The pelvic limb of rats was immobilized for seven days. The exercise protocol consisted of five swimming sessions, once per day and 25 minutes per session. The gastrocnemius muscle was subjected to tensile tests, and evaluated the properties: load at the maximum limit, stretching at the maximum limit and stiffness.

Results

The immobilization reduced the values of load at the maximum limit and the remobilization protocols were not sufficient to restore control levels in adult group and older rats. The stretching at the maximum limit differs only in the older group.

Conclusions

The immobilization reduces the muscle's ability to bear loads and exercise protocol tends to restore the default at control values in adult and older rats. The age factor only interfered in the stretching at the maximum limit, inducing a reduction of this property in the post-immobilization. Level of Evidence II, Investigating the Results of Treatment.

Efeito da crioterapia na resposta eletromiográfica dos músculos tibial anterior, fibular longo e gastrocnemio lateral de atletas após o movimento de inversão do tornozelo

A crioterapia é utilizada para tratamento de traumas no tornozelo/pé em atletas; entretanto, sua ação sobre o controle motor apresenta controvérsias. Este estudo objetivou verificar o efeito da crioterapia na resposta eletromiográfica dos músculos do tornozelo de atletas após inversão. A amostra foi composta por 20 voluntários: 10 universitários atletas de basquetebol e 10 universitários não atletas. Todos foram submetidos à inversão do tornozelo em plataforma para a análise do sinal eletromiográfico dos músculos Gastrocnêmio Lateral (GL), Tibial Anterior (TA) e Fibular Longo (FL), pré e pós-crioterapia por imersão do tornozelo, a 4±2ºC, por 20 minutos. A análise estatística utilizou o teste de Shapiro Wilk, Wilcoxon e Mann-Whitney, com nível de significância em 5%. Considerou-se o pico de RMS, o RMS após 0,2 segundos e após 1,0 segundo da abertura da plataforma de inversão. Todos os dados foram normalizados pelo pico do RMS no momento pré-crioterapia. Evidenciou-se diminuição do pico do RMS e do RMS até 0,2 s para o TA nos atletas e nos músculos GL e FL dos não atletas. Após um segundo da abertura da plataforma houve menor recrutamento dos músculos GL, TA e FL para os não atletas. A comparação entre atletas e não atletas apontou, no RMS até 1 segundo, menor recrutamento para o GL dos atletas pré-crioterapia e TA pré e após o resfriamento. Conclui-se que a crioterapia diminuiu a resposta eletromiográfica do músculo TA de atletas e GL, TA e FL de não atletas.