Morphometric Effects of Whole-Body Vibration on the Bone in a Rat Model of Postmenopausal Osteoporosis.

OBJECTIVE: The purpose of this study was to analyze the morphometric effects of mechanical vibration with a duration of 4 or 8 weeks on the femur of oophorectomized Wistar rats. METHODS: Sixty-four female rats were submitted to oophorectomy or a sham operation, and each of those 2 groups were randomized into 4 groups: untreated and euthanized at week 12, untreated and euthanized at week 16, treated for 4 weeks and euthanized at week 12, and treated for 8 weeks and euthanized at week 16. The vibration treatment was performed for 10 min/d, with a frequency of 60 Hz, 3 d/wk. The rats were then euthanized and the right femur dissected. Subsequently, histomorphometric analysis was performed on the proximal epiphysis and diaphysis of the spongy and cortical bone, respectively. RESULTS: As expected, the oophorectomy groups presented reduction of spongy and cortical bone tissue. Further, the vibration therapy of 4 and 8 weeks' duration in the oophorectomized groups led to increased bone mass, observed as an increased percentage of spongy tissue, and increased thickness and percentage of cortical tissue. However, the variables of femoral neck diameter, mean area of the shaft, and number of osteocytes were not altered by oophorectomy and vibration. CONCLUSION: The mechanical vibration was effective in increasing the bone mass of the femur of oophorectomized Wistar rats, observed by increasing the percentage of spongy bone and increasing the percentage and thickness of cortical bone.

Comparison of low level laser, ultrasonic therapy and association in joint pain in Wistar rats.

INTRODUCTION: Both therapeutic ultrasound as a low level laser therapy are used to control musculoskeletal pain, despite controversy about its effects, yet the literature is poor and also presents conflicting results on possible cumulative effects of techniques association. The aim was to compare the antinociceptive effects of low level laser therapy, therapeutic ultrasound and the association. METHODS: 24 Wistar rats were divided into: GPL--induction of hyperesthesia in the right knee, and untreated; GUS--treated with therapeutic ultrasound (1 MHz, 0.4 W/cm2) GL--low intensity laser (830 nm, 8 J/cm2); GL+US--treated with both techniques. To produce the hyperesthesia 100 µl of 5% formalin solution were injected into the tibiofemoral joint space, which was assessed by von Frey filament digital before (EV1), 15 (EV2), 30 (EV3) and 60 (EV4) minutes after induction. RESULTS: In comparison within groups, for the withdrawal threshold when the fi lament was applied to the knee, the back to baseline was observed only for GUS. Comparisons between groups were not different in EV3, and GL was higher than GPL. In EV4 the three groups effectively treated were higher than placebo. On withdrawal threshold on the plantar surface, GL showed return to baseline values already in EV3, and GUS and GL+US returned in EV4. Comparing the groups in EV3 there was a significantly lower threshold to compare GPL with GL and GUS (p <0.05), and there was only EV4 differences when comparing GPL with GUS. CONCLUSION: Both modalities showed antinociceptive effects.

Comparação entre o laser de baixa potência, ultrassom terapêutico e associação, na dor articular em ratos Wistar / Comparison of low level laser, ultrasonic therapy and association in joint pain in Wistar rats

Introdução: Tanto o ultrassom terapêutico quanto o laser de baixa potência são utilizados para o controle da dor musculoesquelética, apesar de controvérsias. Ainda, a literatura é pobre e também apresenta resultados controversos sobre efeitos cumulativos da associação de técnicas. Assim, o objetivo foi comparar os efeitos antinociceptivos do laser, do ultrassom e da associação destes. Métodos: Foram utilizadas 24 ratas, divididas em: GPL - indução de hiperestesia no joelho direito, e não tratadas; GUS - ultrassom terapêutico (1 MHz, 0,4 W/cm2); GL - laser de baixa potência (830 nm, 8 J/cm2); GL+US - tratadas com as duas técnicas. Para a hiperestesia foram injetados no espaço tíbio-femoral 100 μl de solução de formalina 5%, e avaliada por filamento de von Frey digital, antes (AV1), 15 (AV2), 30 (AV3) e 60 (AV4) minutos após a indução. Resultados: Na comparação dentro dos grupos, para o limiar de retirada quando o filamento foi aplicado nos joelhos, foi possível observar volta aos valores basais apenas para GUS. Nas comparações entre os grupos houve diferenças em AV3, sendo que GL foi maior do que PL. Em AV4 os três grupos tratados apresentaram valores maiores que o placebo. No limiar de retirada na superfície plantar GL mostrou retorno dos valores basais em AV3, e GUS e GL+US retornaram em AV4. Na comparação entre os grupos, em AV3 havia um limiar menor em GPL ao comparar com GL e GUS (p<0,05), e em AV4 só havia diferenças ao comparar GPL com GUS. Conclusão: Ambas as modalidades apresentaram efeitos antinociceptivos. .

Introduction: Both therapeutic ultrasound as a low level laser therapy are used to control musculoskeletal pain, despite controversy about its effects, yet the literature is poor and also presents conflicting results on possible cumulative effects of techniques association. The aim was to compare the antinociceptive effects of low level laser therapy, therapeutic ultrasound and the association. Methods: 24 Wistar rats were divided into: GPL - induction of hyperesthesia in the right knee, and untreated; GUS - treated with therapeutic ultrasound (1 MHz, 0.4 W / cm2) GL - low intensity laser (830 nm, 8 J/cm2); GL+US - treated with both techniques. To produce the hyperesthesia 100 μl of 5% formalin solution were injected into the tibiofemoral joint space, which was assessed by von Frey filament digital before (EV1), 15 (EV2), 30 (EV3) and 60 (EV4) minutes after induction. Results: In comparison within groups, for the withdrawal threshold when the fi lament was applied to the knee, the back to baseline was observed only for GUS. Comparisons between groups were not different in EV3, and GL was higher than GPL. In EV4 the three groups effectively treated were higher than placebo. On withdrawal threshold on the plantar surface, GL showed return to baseline values already in EV3, and GUS and GL+US returned in EV4. Comparing the groups in EV3 there was a significantly lower threshold to compare GPL with GL and GUS (p <0.05), and there was only EV4 differences when comparing GPL with GUS. Conclusion: Both modalities showed antinociceptive effects. .