Physical Exercise and Low-Level Laser Therapy Systemic Effects on the Ankle Joint in an Experimental Rheumatoid Arthritis Model.

OBJECTIVE: The purpose of this study was to analyze the systemic effects of stair climbing exercise, low-level laser therapy (LLLT), and the association of both treatments on pelvic member functionality and ankle joint histomorphometric aspects of Wistar rats submitted to experimental rheumatoid arthritis (RA) protocol. METHODS: Male Wistar rats were randomly distributed into the following 8 groups: control; control LLLT; control exercise; control LLLT and exercise; arthritis group; arthritis LLLT; arthritis exercise; and arthritis LLLT and exercise, with n = 8 for functional and n = 5 for histomorphometrical tests. The experimental RA was induced by complete Freund adjuvant injection in the knee joint cavity. Functionality was evaluated by proprioception and motor function using Sciatic Functional Index and maximum angle reached at an inclined plane. Histomorphometrical aspects were evaluated in the ankle joint after histological routine. RESULTS: The arthritis LLLT and exercise group had positive effects in Sciatic Functional Index (F [3.96] = 11.3, P < .001) and in inclined plane (F [3.4] = 36.1, P < .001). The arthritis exercise group presented a greater number of chondrocytes in the tibia (Wald [1; 6605.6] = 25.2, P < .001) and talus (Wald [1; 15958.6] = 19.8, P = .006) in relation to the other groups. The arthritis group morphology showed significant degenerative lesions as subintima with angiogenesis, inflammatory cells, flocculated articular cartilage, chondrocytes disorganization and pannus. Even with the higher chondrocytes number, the arthritis exercise group had morphological characteristics more similar to the control group. CONCLUSION: Low-level laser therapy and exercise restored functionality, and exercise restored morphological aspects of tissues in experimentally induced RA in rats.

Low-Level Laser Therapy in Different Wavelengths on the Tibialis Anterior Muscle of Wistar Rats After Nerve Compression Injury.

OBJECTIVE: Traumatic injuries are common and may promote disruption of neuromuscular communication, triggering phenomena that lead to nerve degeneration and affect muscle function. A laser accelerates tissue recovery; however, the parameters used are varied, making it difficult to compare studies. The purpose of this study was to evaluate the effect of low-level laser therapy, at 660- and 830-nm wavelengths, on the tibialis anterior muscle of Wistar rats after sciatic nerve compression. METHODS: Twenty animals were separated into 4 groups: control, sciatic nerve injury, lesion + 660-nm laser, and lesion + 830-nm laser. In the lesion groups, the right sciatic nerve was surgically exposed and compressed with hemostatic forceps for 30 seconds. After the third postoperative day, the groups with laser therapy were submitted to treatment for 2 weeks totaling 10 applications, performed directly on the surgical scar of the nerve injury. Grip strength was analyzed before and after the nerve injury and during the treatment period. The tibialis anterior muscle was processed for light microscopy, area measurement, smaller diameter, number of fibers, nuclei, and connective tissue. RESULTS: The animals submitted to the injury experienced muscular atrophy and morphological changes in the number of muscle fibers and nuclei. In the connective tissue morphometry, there was a decrease in the treated groups compared with the untreated groups. CONCLUSION: The laser treatment at different wavelengths showed no improvement in the tibialis anterior muscle of Wistar rats within the morphological and functional aspects evaluated.

Intrathecally injected tramadol reduces articular incapacitation and edema in a rat model of lipopolysaccharide (LPS)-induced reactive arthritis.

AIMS: Intrathecal injection of morphine presents analgesic and antiedematogenic effects in rats. However, it is unknown whether tramadol, which possess a mixed mechanism of action, can also produce analgesic and antiedematogenic effects similarly. MAIN METHODS: Male Wistar rats received carrageenan and LPS in the right knee joint. Tramadol (10 µg) was injected intrathecally 20 min before articular LPS injection. Incapacitation and articular edema were measured 5 h after LPS stimulation. Synovial fluid was collected for leukocyte counting and western blot analysis. Whole joint and lumbar spinal cord were also collected for histology and immunohistochemistry, respectively. Intrathecal pretreatments groups were with the NKCC1 blocker bumetanide, TRPV1 agonist resiniferatoxin, µ-opioid receptor antagonist CTOP and serotonergic neurotoxin 5,7-DHT, all previously to tramadol. KEY FINDINGS: Tramadol treatment caused the reduction of incapacitation and edema. It also reduced c-Fos protein expression in the spinal cord dorsal horn and slightly reduced TNF-α levels in synovial fluid, but neither reduced cell migration nor tissue damage. Bumetanide and resiniferatoxin prevented the analgesic and antiedematogenic effects of tramadol. CTOP prevented the analgesic and the antiedematogenic effects, but 5,7-DHT prevented only tramadol-induced analgesia. SIGNIFICANCE: Spinal NKCC1 cotransporter and peptidergic peripheral afferents seem to be important for the analgesic and antiedematogenic effects of tramadol, as well as µ-opioid receptor. However, the monoamine uptake inhibition effect of tramadol seems to be important only to the analgesic effect.