ABSTRACT
The main purpose of this work was to construct an energy-dependent response curve of photobiomodulation on arterial pressure in hypertension animal model. To reach this objective, we have used a two-kidney one clip (2K-1C) rat model. Animals received acute laser light irradiation (660 nm) on abdominal region using different energy (0.6, 1.8, 3.6, 7.2, 13.8, 28.2, 55.8, and 111.6 J), the direct arterial pressure was measured by femoral cannulation, and systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), and time of effect were obtained. Our results indicated that 660 nm laser light presents an energy-dependent hypotensive effect, and 28.2 J energy irradiation reached the maximum hypotensive effect, inducing a decreased SAP, DAP, and HR (decrease in SAP: - 19.23 ± 1.82 mmHg, n = 11; DAP: - 9.57 ± 2.23 mmHg, n = 11; HR: - 39.15 ± 5.10 bpm, n = 11; and time of hypotensive effect: 3068.00 ± 719.00 s, n = 11). The higher energy irradiation evaluated (111.6 J) did not induce a hypotensive effect and induced an increase in HR (21.69 ± 7.89 bpm, n = 7). Taken together, our results indicate that red laser energy irradiation from 7.2 to 55.8 J is the effective therapeutic window to reduce SAP, DAP, MAP, and HR and induce a long-lasting hypotensive effect in rats, with effect loss at higher energy irradiation (111.6 J).
Subject(s)
Blood Pressure , Hypertension/physiopathology , Hypertension/radiotherapy , Low-Level Light Therapy , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Diastole/physiology , Heart Rate , Hypotension/physiopathology , Male , Rats, Wistar , Systole/physiologyABSTRACT
Skin Flap is used in reconstructive plastic surgery. However, complications such as ischemia followed by local necrosis may occur, requiring a new surgical procedure. It is well known that photobiomodulation therapy (PBMT) is an effective technique for improving microcirculation and neoangiogenesis, which contributes positively to the blood supply in the pre and post surgical period. Thus, the objective of the present study was to investigate the effects of preemptive treatment with laser PBMT with different energies on the viability in skin flaps in rats. Sixty-three Wistar rats, male, were randomized into five groups: Control Group (CG) (nâ¯=â¯15): PBMT simulation; Preemptive group 1.1â¯J laser (GP1) (nâ¯=â¯15): preemptive laser PBMT with 1.1â¯J of energy per point; Preemptive group 4â¯J laser (GP4) (nâ¯=â¯15): preemptive PBMT with 4â¯J of energy per point; Laser group 11â¯J (G1) (nâ¯=â¯9): PBMT immediately after surgery with 1.1â¯J of energy per point; Laser group 4â¯J (G4) (nâ¯=â¯9): TFMB immediately after surgery with 4â¯J of energy per point. The CG, GP1 and GP4 groups started treatment 72â¯h prior to surgery and were subdivided into two experimental periods, one of them on the day of the flap and the other along with the other groups on the seventh postoperative day. Three days after the randomization, the animals underwent random skin flap surgery. PBMT was performed with a 660â¯nm laser at three points. In the first experimental period, a greater number of vessels were found, as well as mast cells in GP1 compared to the CG and greater expression of fibroblast growth factor and vascular endothelial growth factor in the GP1 and GP4 groups compared to the CG. In the second experimental period, GP1 presented a lower percentage of necrotic tissue, a higher number of vessels and a percentage of cells labeled with both VEGF and hypoxia indicible factor alpha (HIF-1α) compared to the CG, FGF in GP1, GP4 and G4 when compared to the CG. Thus, it was concluded that preemptive treatment with PBMT with the application of 1.1â¯J of energy per point is effective in improving the viability of the skin flap.
Subject(s)
Lasers, Semiconductor , Surgical Flaps , Animals , Male , Rats , Blood Vessels/pathology , Blood Vessels/radiation effects , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mast Cells/cytology , Mast Cells/metabolism , Mast Cells/radiation effects , Necrosis , Random Allocation , Rats, Wistar , Surgical Flaps/blood supply , Surgical Flaps/pathology , Vascular Endothelial Growth Factor A/metabolismABSTRACT
Follicular cystic ovary disease is a common reproductive disorder in women and females of domestic animals, characterized by anovulation and the persistence of follicle is a common cause of reproductive failure in mammalian. Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism (HA), chronic anovulation and polycystic ovaries, and it is a common reproductive endocrine disease with clinical manifestations including hirsutism, acne, infertility and obesity that can affect 5-20% of women in their reproductive age. Photobiomodulation (PBM) has been investigated and used in clinical practice, related to biomodulatory influences on cellular functions in animals and humans, both in vivo and in vitro. In this study, we include endocrine and reproductive features in a rat model for PCOS and the effects of PBM on ovarian activities. Forty-five adult female Wistar rats PCOS-induced by a single dose of the estradiol valerate (EV) were used in the study. After the EV injection for PCO induction, rats were divided into 9 groups (nâ¯=â¯5/group) named C30, C45 and C60 (Control group), S30, S45 and S60 (PCO group) and L30, L45 and L60 (PCO/Laser group). The rats were irradiated with laser 3 times/week. The results shown that EV PCO-induced rats had increased body mass, reduced ovary mass, and reduced GSI. The plasma levels of P4 and T were increased, and the LH plasma level was decreased by PBM stimulation. The number of ovarian follicles and corpus luteum were increased, and the number of ovarian cysts was decreased by PBM stimulation. Thus, reproductive and endocrine characteristics were modulated by PBM.
Subject(s)
Low-Level Light Therapy , Ovary/physiopathology , Ovary/radiation effects , Polycystic Ovary Syndrome/radiotherapy , Animals , Corpus Luteum/pathology , Corpus Luteum/radiation effects , Estrous Cycle/radiation effects , Female , Hormones/blood , Ovary/pathology , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/pathology , Polycystic Ovary Syndrome/physiopathology , Rats , Rats, WistarABSTRACT
To identify the best low level laser photobiomodulation application site at the same irradiation time to increase the viability of the skin flap in rats. Eighteen male rats (Rattus norvegicus: var. Albinus, Rodentia Mammalia) were randomly distributed into three groups (n = 6). Group I (GI) was submitted to simulated laser photobiomodulation; group II (GII) was submitted to laser photobiomodulation at three points in the flap cranial base, and group III (GIII) was submitted to laser photobiomodulation at 12 points distributed along the flap. All groups were irradiated with an Indium, Galium, Aluminum, and Phosphorus diode laser (InGaAlP), 660 nm, with 50 mW power, irradiated for a total time of 240 s in continuous emission mode. The treatment started immediately after performing the cranial base random skin flap (10 × 4 cm2 dimension) and reapplied every 24 h, with a total of five applications. The animals were euthanized after the evaluation of the percentage of necrosis area, and the material was collected for histological analysis on the seventh postoperative day. GII animals presented a statistically significant decrease for the necrosis area when compared to the other groups, and a statistically significant increase in the quantification of collagen when compared to the control. We did not observe a statistical difference between the TGFß and FGF expression in the different groups evaluated. The application of laser photobiomodulation at three points of the flap cranial base was more effective than at 12 points regarding the reduction of necrosis area.
Subject(s)
Low-Level Light Therapy , Skin/radiation effects , Surgical Flaps , Tissue Survival/radiation effects , Animals , Cell Nucleus/metabolism , Cell Nucleus/radiation effects , Collagen/metabolism , Fibroblast Growth Factors/metabolism , Fibroblasts/metabolism , Fibroblasts/radiation effects , Lasers, Semiconductor , Male , Necrosis , Rats, Wistar , Transforming Growth Factor beta/metabolismABSTRACT
Wound healing is a complex biological process with specific phases. Photobiomodulation (PBM) decreases the inflammatory infiltrate, stimulating fibroblast proliferation and angiogenesis, and therefore, is indicated for wound healing. Vitamin A is used to reverse the inhibitory effects on wound healing and accelerate the healthy granulation tissue. The study aimed to evaluate the effect of topical vitamin A and PBM (GaAlAs) in inflammatory phase of cutaneous wounds. Forty Wistar male rats were separated into four groups: (1) control (CG); (2) laser group (LG) GaAlAs, 670 nm, 30 mW, energy per point of 0.9 J, radiating by 1 point in 30 s; (3) vitamin A group (VitAG); and (4) laser group plus vitamin A (LG + VitAG). Wounds were surgically made by a punch biopsy with 10 mm of diameter on the back of the animals and all treatments were started according to the experiment. The treatments were administered for four consecutive days and biopsy was performed on day 4. We performed both H&E and immunohistochemistry analysis. The results were compared between groups by one-way analysis of variance ANOVA test with post hoc Tukey (p < 0.05). Inflammatory infiltrate increased significantly in LG compared to CG and VitAG (p < 0.05). Regarding angiogenesis, VEGF expression was increased significantly in LG and LG + VitAG groups, p < 0.01. The results indicate that proposed treatments were effective on the healing process improved by LG and LG + VitAG. We show that laser plus vitamin A enhances healing by reducing the wound area and may have potential application for clinical management of cutaneous wounds.
Subject(s)
Inflammation/pathology , Low-Level Light Therapy , Vitamin A/pharmacology , Wound Healing/drug effects , Wound Healing/radiation effects , Animals , Biopsy , Cyclooxygenase 2/metabolism , Immunohistochemistry , Lasers, Semiconductor , Male , Rats, Wistar , Skin/pathology , Vascular Endothelial Growth Factor A/metabolismABSTRACT
OBJECTIVES: The healing process of cutaneous lesions is considered a complex event divided into distinct and overlapping phases, which responds satisfactorily to photobiomodulation (PBM). PBM is indicated as a therapeutic resource capable of assisting tissue repair. The present study aimed to analyze the kinetics of cutaneous wounds healing process after application of the GaAlAs laser for treating wounds on the dorsum of rats. MATERIALS AND METHODS: This study was approved by the Animal Ethics Committee of UFSCar. The animals were divided into 2 groups (nâ¯=â¯10); control group (CG) used 0.9% saline solution and the laser group (LG) used GaAlAs, 670â¯nm continuous pulse, 30â¯mW power, 14.28â¯J/cm2 energy density, irradiating 1 point per wound for 30s, totaling 15 consecutive days of treatment. Samples were collected on the 4th, 11th and 16th days for histological analysis of HE, Picrosirius-Red, immunohistochemistry (Collagen1, TNF-α, VEGF). Statistical analyzes used the one-way ANOVA test for intra and inter group evaluations, and the Tukey post-test. Level of significance was set at pâ¯<â¯0.05. RESULTS: The histopathological analysis (HE) showed a statistically significant difference for lower values of inflammatory infiltrate in LG versus CG on the 16th day; and for the increase of collagen in the 11th and 16th days of treatment. There was a statistically significant difference in the increase of VEGF on the 11th day for LG; decrease of TNF-α on the 4th and 11th day for LG, and increase of collagen type 1 on the 4th and 16th days for LG. The birefringence analysis of the percentage of collagen fibers presented on the 11th day of treatment revealed a greater quantity and significant statistical difference. Collagen fibers showed improved organization and arrangement on the 11th day for LG. CONCLUSION: Our results show that PBM is effective in helping the kinetics of the cutaneous wound healing process in rats and promotes the necessary stimuli for the satisfactory evolution of healing process, ultimately leading to structurally desirable tissue.
Subject(s)
Lasers, Semiconductor , Wound Healing/radiation effects , Animals , Birefringence , Collagen Type I/metabolism , Immunohistochemistry , Male , Rats , Rats, Wistar , Skin/metabolism , Skin/pathology , Skin/radiation effects , Tumor Necrosis Factor-alpha/metabolism , Vascular Endothelial Growth Factor A/metabolismABSTRACT
The purpose of this study was to evaluate the acute effect of photobiomodulation therapy (PBM) on arterial pressure in hypertensive and normotensive rats with application in an abdominal region. Normotensive (2K) and hypertensive (2K-1C) wistar rats were treated with PBM. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and heart rate (HR) were measured before, during and after PBM application. The nitric oxide (NO) serum concentration was measured before and after PBM application. Vascular reactivity study was performed in isolated thoracic aortas. Aluminum gallium arsenide (GaAlAs) diode laser was used, at 660nm wavelength and 100mW optical output. The PBM application induced a decrease of SAP in 2K-1C rats. In 2K rats, the PBM application had no effect on SAP, DAP and MAP. Moreover, the magnitude of hypotensive effect was higher in 2K-1C than in 2K rats. The PBM application induced a decrease of HR in 2K-1C and 2K, with higher effect in 2K-1C rats. In 2K-1C, the hypotensive effect induced by PBM was longer than that obtained in 2K rats. PBM application induced an elevation of NO concentration in serum from 2K-1C and 2K rats, with higher effect in 2K-1C. In isolated aortic rings PBM effect is dependent of NO release, and is not dependent of nitric oxide synthase (NOS) activation. Our results indicate that the abdominal acute application of PBM at 660nm is able to induce a long lasting hypotensive effect in hypertensive rats and vasodilation by a NO dependent mechanism.
Subject(s)
Arterial Pressure/radiation effects , Hypertension/radiotherapy , Lasers, Semiconductor/therapeutic use , Low-Level Light Therapy/methods , Nitric Oxide/blood , Animals , Aorta, Thoracic/metabolism , Aorta, Thoracic/radiation effects , Disease Models, Animal , Heart Rate/radiation effects , Hypertension/physiopathology , Male , Nitric Oxide Synthase/metabolism , Rats , Rats, Wistar , Time Factors , Vasodilation/radiation effectsABSTRACT
Bioactive glasses (BGs) are known for their ability to bond to living bone and cartilage. In general, they are readily available in powder and monolithic forms, which are not ideal for the optimal filling of bone defects with irregular shapes. In this context, the development of BG-based scaffolds containing flexible fibres is a relevant approach to improve the performance of BGs. This study is aimed at characterizing a new, highly porous, fibrous glassy scaffold and evaluating its in vitro and in vivo biocompatibility. The developed scaffolds were characterized in terms of porosity, mineralization and morphological features. Additionally, fibroblast and osteoblast cells were seeded in contact with extracts of the scaffolds to assess cell proliferation and genotoxicity after 24, 72 and 144 h. Finally, scaffolds were placed subcutaneously in rats for 15, 30 and 60 days. The scaffolds presented interconnected porous structures, and the precursor bioglass could mineralize a hydroxyapatite (HCA) layer in simulated body fluid (SBF) after only 12 h. The biomaterial elicited increased fibroblast and osteoblast cell proliferation, and no DNA damage was observed. The in vivo experiment showed degradation of the biomaterial over time, with soft tissue ingrowth into the degraded area and the presence of multinucleated giant cells around the implant. At day 60, the scaffolds were almost completely degraded and an organized granulation tissue filled the area. The results highlight the potential of this fibrous, glassy material for bone regeneration, due to its bioactive properties, non-cytotoxicity and biocompatibility. Future investigations should focus on translating these findings to orthotopic applications. Copyright © 2015 John Wiley & Sons, Ltd.
Subject(s)
Biocompatible Materials/pharmacology , Glass/chemistry , Materials Testing/methods , Tissue Scaffolds/chemistry , Animals , Calcification, Physiologic/drug effects , Cell Death/drug effects , Cell Proliferation/drug effects , Hydrogen-Ion Concentration , Male , Mice , Mutagenicity Tests , Osteoblasts/cytology , Osteoblasts/drug effects , Porosity , Rats, Wistar , Spectroscopy, Fourier Transform Infrared , Subcutaneous Tissue/pathologyABSTRACT
Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone regeneration induced by the fibrous material.
Subject(s)
Bone Regeneration/physiology , Bone Transplantation/instrumentation , Glass/chemistry , Tibial Fractures/pathology , Tibial Fractures/therapy , Tissue Scaffolds , Absorbable Implants , Animals , Bone Substitutes/chemical synthesis , Bone Substitutes/therapeutic use , Equipment Failure Analysis , Male , Prosthesis Design , Rats , Rats, Wistar , Treatment OutcomeABSTRACT
The aim of the present study was to analyse the lactate threshold (LT) changes in rats submitted to an aerobic treadmill-training programme. Twenty-five Wistar rats were divided into two groups: a sedentary control group (CG), and a trained group (TG) submitted to an aerobic training during 5 weeks. All the animals were submitted to an incremental treadmill exercise test in order to determine LT. There was an increase in the maximum running speed in the TG (from 32.25 ± 1.27 to 47.75 ± 3.13 m.min-1 - p = 0.001), and running speed at LT (from 26.21 ± 1.15 to 35.30 ± 2.24 m.min-1 - p = 0.004), a part from the reduction in blood lactate at LT. LT can be determined in rats, and aerobic training induced positive oxidative physiological adaptations in the animals.
Subject(s)
Adaptation, Physiological/physiology , Lactates/blood , Oxygen Consumption/physiology , Physical Conditioning, Animal/physiology , Running/physiology , Animals , Male , Rats, Wistar , Time FactorsABSTRACT
OBJECTIVE: The aim of this study was to investigate the effects of 670-nm, 780-nm, and 830-nm laser irradiation on cell proliferation of normal primary osteoblast (MC3T3) and malignant osteosarcoma (MG63) cell lines in vitro. BACKGROUND: Some studies have shown that laser phototherapy is able to stimulate the osteogenesis of bone tissue, increasing osteoblast proliferation and accelerating fracture consolidation. It has been suggested that laser light may have a biostimulatory effect on tumor cells. However, the mechanism by which the laser acts on cells is not fully understood. MATERIALS AND METHODS: Neonatal, murine, calvarial, osteoblastic, and human osteosarcoma cell lines were studied. A single laser irradiation was performed at three different wavelengths, at the energies of 0.5, 1, 5, and 10 J/cm(2). Twenty-four hours after laser irradiation, cell proliferation and alkaline phosphatase assays were assessed. RESULTS: Osteoblast proliferation increased significantly after 830-nm laser irradiation (at 10 J/cm(2)) but decreased after 780-nm laser irradiation (at 1, 5, and 10 J/cm(2)). Osteosarcoma cell proliferation increased significantly after 670-nm (at 5 J/cm(2)) and 780-nm laser irradiation (at 1, 5, and 10 J/cm(2)), but not after 830-nm laser irradiation. Alkaline phosphatase (ALP) activity in the osteoblast line was increased after 830-nm laser irradiation at 10 J/cm(2), whereas ALP activity in the osteosarcoma line was not altered, regardless of laser wavelength or intensity. CONCLUSION: Based on the conditions of this study, we conclude that each cell line responds differently to specific wavelength and dose combinations. Further investigations are required to investigate the physiological mechanisms responsible for the contrasting outcomes obtained when using laser irradiation on cultured normal and malignant bone cells.
Subject(s)
Cell Differentiation/radiation effects , Cell Proliferation/radiation effects , Low-Level Light Therapy/methods , Osteoblasts/radiation effects , Osteogenesis/radiation effects , Osteosarcoma/radiotherapy , Alkaline Phosphatase/metabolism , Analysis of Variance , Animals , Biomarkers/metabolism , Cell Line , Cell Transformation, Neoplastic , Humans , In Vitro Techniques , Mice , Osteoblasts/metabolism , Osteosarcoma/pathology , Skull/radiation effects , Tumor Cells, CulturedABSTRACT
OBJETIVO: Comparar a influência da terapia laser baixa intensidade (TLBI) na organização das fibras de colágeno, na dose de 3J/cm² em dois comprimentos de onda (lambda) (670nm e 904nm) e na associação de ambos, durante o reparo do tendão calcâneo de ratos. MÉTODO Foram utilizadas 37 ratas da raça Wistar divididas em 5 grupos, submetidas a tenotomia total por meio de cisalhamento transversal do tendão na porção média entre a inserção calcânea e a junção miotendínea, com exceção do grupo GP (n= 6) que não houve lesão. O grupo GA (n= 8) foi submetido à irradiação laser lambda= 904nm, diodo de GaAs, emissão pulsada, duração do pulso de 180ns, freqüência de pulso de 2000Hz e potência de pico de 15W e dose de 3J/cm². O grupo GB (n= 8) foi submetido à irradiação laser lambda= 670nm, diodo de AlGaInP, emissão contínua, potência 30mW e dose de 3J/cm². O grupo GAB (n= 8) recebeu irradiação de ambos os lasers 670nm e 904nm associados. O grupo GCL (n= 7) foi submetido a um tratamento placebo, assim como um grupo padrão. Após um total de 12 sessões de laserterapia, os animais foram submetidos à eutanásia no 14º dia pós-operatório. Após processamento histológico padrão, foi realizada a quantificação do retardo óptico pela birrefringência. RESULTADOS: A análise estatística mostra que todos os grupos irradiados apresentaram valores de retardo óptico maiores quando comparados ao grupo placebo (p= 0,00001), o que indica que apresentaram melhor organização das fibras colágenas ao longo do eixo longitudinal do tendão, evidenciando melhor qualidade no reparo. O grupo GAB foi o que apresentou melhores resultados (p= 0,00001) quando comparado aos demais grupos, excetuando-se o GP, que é o referencial de retardo óptico para esta faixa etária.
OBJECTIVE: The aim of this study was to compare the effect of the low level laser therapy in the organization of the collagen fibers with 3 J/cm² of dose in two wavelengths (670nm and 904nm) and in the combination of both on the tissue repair of the calcaneus tendon. METHODS: We used 37 female Wistar rats divided in 5 groups which had been submitted to the total tenotomy. Group GA (n= 8) was submitted to the laser irradiation in lambda= 904nm, GaAS diode, pulsated emission, peak power 15W and dose of 3J/cm², group GB (n= 8) was submitted to laser irradiation lambda= 670nm AlGaInP diode, continuous emission, power 30 mW and dose 3J/cm², group GAB (n= 8) was submitted to association of both of lasers and group GCL (n= 7) which the calcaneum tendon was submitted to placebo treatment. The group GP (n= 6) was a standard group without lesion and treatment. The animals received 12 sessions of lasertherapy and submitted to euthanasia on 14th day after surgery. The tendons were submitted to histological procedure and were analyzed to evaluate the optic retardation (in nm) for the birefringence measurement. RESULTS: The statistic analysis showed that the irradiated groups have higher values of optic retardation statistically significant than placebo group (p= 0,00001). It indicates that all the treated groups show better organization of collagen fibers in the longitudinal axis of the tendon, evidencing better quality in the tissue repair. The group GAB was that shown best results (p= 0,00001) when compared to another groups.
Subject(s)
Rats , Animals , Achilles Tendon , Birefringence , Low-Level Light Therapy , Rats, WistarABSTRACT
OBJETIVO: Verificar a atividade e padrão eletroforético da LDH em resposta ao exercício em esteira em ratos submetidos à fotoestimulação por laser de baixa intensidade (780 etam). MÉTODO: Foram utilizados nesse estudo 54 ratos machos jovens (30dias), Winstar, com peso inicial médio de 112 ± 4,7g, os quais foram divididos em quatro grupos: dois permaneceram em repouso, GRC (grupo repouso controle, n= 9) e GRL (grupo repouso laser, n= 10), sendo o segundo irradiado por laser, e outros dois foram submetidos ao treinamento aeróbio e testes de esforço crescente em esteira (em degraus descontínuos) visando à determinação do limiar de anaerobiose (LA) durante 5 semanas, GEC (grupo exercício controle, n= 16) e GEL (grupo exercício laser, n= 19), sendo o último também irradiado por laser. O laser foi aplicado no quadríceps, glúteo máximo, sóleo e tibial anterior (TA), bilateralmente, imediatamente após cada sessão de treinamento, usando: 3,8J/cm², 15mW, 10s, modo contínuo, durante 5 semanas. Amostras de sóleo, TA e coração foram removidas 48 horas após a última sessão de exercício para análise eletroforética e espectrofotométrica. A estatística foi realizada através do teste ANOVA e post-hoc de TUKEY. O nível de significância foi considerado (p< 0,05). RESULTADOS: Foram observadas reduções na atividade da LDH causadas pelo laser (de 19 por cento a 30 por cento), exercício (de 41 por cento a 66 por cento) e as ações combinadas (de 47 por cento a 66 por cento) (p< 0,01). A eletroforese mostrou uma predominância da subunidade B para o sóleo e coração, e uma predominância da subunidade A no TA. CONCLUSÕES: Estes dados sugerem uma melhor resposta adaptativa dos animais ao treinamento aeróbio associado à terapia laser, no que se refere à otimização da via oxidativa.
Subject(s)
Animals , Rats , Exercise Test , Low-Level Light Therapy , Physical Therapy Modalities , Rats, WistarABSTRACT
O proposito deste estudo foi verificar o limiar de anaerobiose em resposta ao exercicio em estera em ratos submetidos a fotoestimulacao por laser de baixa intensidade (780nm). Metodo: foram utilizados neste estudo 40 ratos machos jovens (30dias), wistar com peso inicial medio de 111+-10g, os quais foram divididos em dois grupos: 1-grupo exercicio controle (GEC) e 2-grupo exercicio laser (GEL), ambos submetidos a um treinamento aerobio em esteira e a testes de esforco crescente (em degraus descontinuos) visando a determinacao do limiar de anaerobiose. O laser foi aplicado nos principais musculos da marcha, imediatamente apos cada sessao de treinamento. Para a dosagem do lactato utilizou-se um lactimetro. A estatistica foi realizada por meio dos testes ANOVA e post-hoc de TUKEY. O nivel de significancia foi considerado (p<-0,05). resultados: apos o periodo de treinamento os dois grupos exibiram aumento na velocidade maxima da corrida e o limiar de anaerobiose se mostrou deslocado para um nivel de maior esforco (p<0,01). As medidas de lactacidemia mostraram ligeira reducao durante a obtencao do limiar de anaerobiose, sobretudo no GEC. Entretanto, nao houve diferenca estatisticamente significativa entre os grupos para as variaveis analisadas, apesar de o GEL ter mostrado comportamento diferenciado no decorrer das semanas, no que se refere ao padrao da curva de esforco. Conclusoes: esses dados sugerem que alteracoes na lactacidemia, em ratos treinados, permitem a determinacao do limiar de anaerobiose e que o treinamento aerobico possibilitou adaptacoes fisiologicas no sentido de aumento na capacidade oxidativa dos animais
Subject(s)
Anaerobic Threshold , Anaerobiosis , Exercise , Lactic Acid , PainABSTRACT
Os efeitos do laser de baixa potencia parecem nao se limitar ao local da aplicacao. Eles podem, por meio dos mediadores metabolicos, chegar a areas mais distantes do corpo promovendo efeitos sistemicos. O objetivo destre trabalho foi analisar as mudancas dos niveis de proteinas sericas, como uma forma de determinar um dos efeitos sistemicos do laser de baixa potencia. Trinta e seis coelhos machos foram induzidos a um processo inflamatorio articular no joelho da pata direita com terebinthina comum (Tc). Foram divididos aleatoriamente em 3 grupos, cada um com 12 animais, e subdivididos em grupos de 6 animais para receber as densidades energeticas diferenciadas de 3.4 J.cm e 8 J.cm. O grupo exerimental agudo (GEA) iniciou o laser 48 horas apos a injecao da Tc o grupo experimental cronico (GEC) recebeu laser 5 dias depois da inducao da inflamacao e o grupo ontrole, que nao recebeu tratamento e foi subdividido, por sua vez, em 6 animais (GCA) que seguiram o mesmo esquema do GEA e outros 6 (GCC), O esquema do GEC. Tambem foi colhido o sangue de outros 30 animais normais para obter um grupo-padrao. Usou-se um laser com comprimento de onda de 830 nm e potencia de 77 mW, aplicado durante 7 dias, uma sessao a cada 24 horas. O sangue foi processado para eletroforse. O modelo experimental foi adequado, uma vez que os animais dos grupos sob inducao da inflamacao se comportaram diferentemente do grupo-padrao. Nos animais com infamacao induzida, foram observadas as seguintes alteracoes diminuicao acentuada da albumina no GCC, aumento da-globulina no GEA e da-globulina nos GCA e GCC e elevacao da y-globulina no GCC. Poucas diferencas foram encontradas quando comparadas as duas doses de laser rmpregadas (3,4 e 8 J.cm ). Os resultados indicam haver efeito sistematico sobre as proteinas plasmaticas promovido pelo laser de baixa potencia nesse modelo de infamacao articular induzida
Subject(s)
Blood Proteins , Lasers , Proteins , RabbitsABSTRACT
Este estudo teve por objetivo avaliar os efeitos do laser terapeutico de baixa potencia sobre o processo de reparacao ossea em tibia de rato. O modelom experimental consistiu na realizacao de uma osteotomia mecanica por escareacao na face medial da tibia de 48 ratos machos, utilizando uma broca odontologica de aco cilindrica. Os animais foram divididos em 3 grupos, sendo que os grupos 1 e 2 foram irradiados com laser na dose de 5 J/cm2 e 50 J/cm2, respectivamente, enquanto o grupo 3 (controle) recebeu tratamento, respectivamente. Os parametros referentes ao tecido de reparo avaliados foram: 1. comportamento biomecanico ao final de 14 dias PO e 2. morfologia ao final de 7 e 14 dias do PO, referentes ao tecido de reparo. Os chados das analises histomorfologicas dos 7 dias do PO demonstraram melhor evolucao do processo de reparacao no grupo irradiado com a dose de 50 J/cm2, comparado aos demais grupos. Esses resultados sugerem que, sob as condicoes xperiemntais da investigacao, terapia laser de baixa potencia (LLLT) favorece o processo de reparacao ossea durante seus estagios iniciais
Subject(s)
Biomechanical Phenomena , Lasers , Osteotomy , RatsABSTRACT
O primeiro relato da fonoforese aconteceu em 1954, e desde entao vem sendo usada com fequencia pela fisioterapia. Este estudo tem por objetivo analisar a relevancia e a confiabilidade da fonoforese nas desordens musculo-esqueleticas, assim como sua utilizacao clinica. A pesquisa bibliografica foi realizada na base de dados do Probe e Medline, com isso 56 trabalhos foram selecionados entre os anos de 1954 e 2001. Os trabalhos foram analisados pelo criterio de filtros, que verificou a importancia e a presenca de informacoes prefixadas. Apos a analise constatamos que nenhum dos trabalhos respeitava todos os criterios de filtragem estabelecidos. Concluimos entao que a utilizacao da fonoforese ainda representa duvidas quanto a sua relevancia a confiabilidade de seus efeitos positivos julgados pelos autores. Novos estudos que se utilizam de uma analise estatistica mais consistente sao necessarios para que se possa descrever o uso dessa pratica baseado em evidencias
Subject(s)
Phonophoresis , Physical Therapy Specialty , UltrasonicsABSTRACT
A dor e um problema comum para muitos pacientes que buscam a fisioterapia. Controlar a sintomatologia algica e promover capacitacao funcional sao objetivos fundamentais nesses casos. Recentes avancos na neurofisiologia da modulacao e percepcao da dor trouxeram fundamentacao cientifica para o uso dos agentes fisicos nos cuidados dos pacientes, reativando pacientes descondicionados, depressivos e incapacitados por imobilizacao repouso ou desuso prolongado em razao da dor. Portanto, todo fisioterapeuta deveria dominar os mecanismos de dor e analgesia e os principios de acao dos recursos analgesicos. Todavia e falha a formacao do fisioterapeuta em relacao aos temas ligados a dor e a analgesia. Desse modo, o objetivo do presente ensaio e propor um programa de ensino relativo ao papel do fisioterapeuta no alivio da dor, destacando: a terminologia relativa aos fenomenos de dor e analgesia, as bases fisiologicas e os componentes psicologicos, ambientais e culturais da dor, o impacto que a experiencia dolorosa exerce sobre as diversas fases da vida (infancia, adolescencia, fase adulta, velhice), as diversas estrategias de avaliacao e medida clinica da dor, os modelos teoricos, os fundamentos fisiologicos e as evidencias empiricas da efetividade das diversas estrategias fisioterapicas de tratamento e controle da dor, e o papel dos demais profissionais de saude e das diversas especialidades medicas no controle da dor. A disciplina proposta, `Dor e Movimento: Recursos Analgesicos em Fisioterapia`, tem carga horaria sugerida de 60 horas/aula e esta organizada de modo a despertar nos alunos o interesse pelo estudo desse tema, fornecendo-lhes as bases para reflexao posterior mais aprofundada, o que inclui a indicacao das referencias bibliograficas fundadoras, das atuais e das mais facilmente disponiveis, na area dos estudos da dor. A proposicao de uma disciplina especifica busca garantir o tratamento organico da questao, capaz de gerar no aluno reflexao articulada sobre os problemas da dor e de seu alivio
Subject(s)
Analgesia , Pain , Physical Therapy Specialty , TeachingABSTRACT
We evaluated the effect on mice skeletal muscle regeneration of different doses (2.6, 8.4, and 25 J/cm2) of HeNe laser (lambda 632.8 nm; power, 2.6 mW; spot size, 0.007 cm2) applied directly to intact skin of injured muscle. Muscle injury was induced in both right and left Tibialis anterior (TA) muscles by ACL myotoxin (5 mg/kg). Right TA muscles were irradiated daily for 5 days while contralateral muscles received a sham treatment. Only the 2.6 J/cm2 dose resulted in changes such as increased mitochondrial density and muscle fibre in the TA muscles as compared to sham groups (3280 +/- 704 microns 2 versus 2110 +/- 657 microns 2, p = 0.02). We concluded that the HeNe effect on mouse muscle regeneration is dose-specific: only 2.6 J/cm2 increased muscle fibre area and mitochondrial density.