RESUMO
Abstract Purpose: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. Methods: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. Results: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p<0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p<0.0001) and L3 (p<0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. Conclusion: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.
Assuntos
Animais , Masculino , Ratos , Tendão do Calcâneo/efeitos da radiação , Carotenoides/farmacologia , Terapia com Luz de Baixa Intensidade/métodos , Tendinopatia/radioterapia , Tenotomia/métodos , Hidroxibutiratos/farmacologia , Tendão do Calcâneo/cirurgia , Tendão do Calcâneo/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Cicatrização/efeitos da radiação , Distribuição Aleatória , Colágeno/farmacologia , Ratos Wistar , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo III/análise , Colágeno Tipo III/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Fibroblastos/efeitos dos fármacos , Fibroblastos/química , ProibitinasRESUMO
Abstract Purpose: To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair. Methods: Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically. Results: Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107). Conclusion: Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.
Assuntos
Humanos , Animais , Masculino , Poliésteres/farmacologia , Tendão do Calcâneo/cirurgia , Tendão do Calcâneo/efeitos dos fármacos , Carotenoides/farmacologia , Tenotomia/métodos , Hidroxibutiratos/farmacologia , Valores de Referência , Regeneração/efeitos dos fármacos , Tendão do Calcâneo/patologia , Reprodutibilidade dos Testes , Ratos Wistar , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo III/análise , Colágeno Tipo III/efeitos dos fármacos , Fibroblastos/efeitos dos fármacosRESUMO
2-Hydroxybutyric acid appears at high concentrations in situations related to deficient energy metabolism (e.g., birth asphyxia) and also in inherited metabolic diseases affecting the central nervous system during neonatal development, such as "cerebral" lactic acidosis, glutaric aciduria type II, dihydrolipoyl dehydrogenase (E3) deficiency, and propionic acidemia. The present study was carried out to determine the effect of 2-hydroxybutyric acid at various concentrations (1-10 mM) on CO2 production and lipid synthesis from labeled substrates in cerebral cortex of 30-day-old Wistar rats in vitro. CO2 production was significantly inhibited (30-70 percent) by 2-hydroxybutyric acid in cerebral cortex prisms, in total homogenates and in the mitochondrial fraction. We also demonstrated a significant inhibition of lipid synthesis (20-45 percent) in cerebral cortex prisms and total homogenates in the presence of 2-hydroxybutyric acid. However, no inhibition of lipid synthesis occurred in homogenates free of nuclei and mitochondria. The results indicate an impairment of mitochondrial energy metabolism caused by 2-hydroxybutyric acid, a fact that may secondarily lead to reduction of lipid synthesis. It is possible that these findings may be associated with the neuropathophysiology of the situations where 2-hydroxybutyric acid is accumulated
Assuntos
Animais , Ratos , Dióxido de Carbono/metabolismo , Córtex Cerebral/efeitos dos fármacos , Metabolismo Energético , Hidroxibutiratos/farmacologia , Lipídeos/síntese química , Análise de Variância , Hidroxibutiratos/química , Mitocôndrias/metabolismo , Ratos WistarRESUMO
From studies on the release of acid phosphatase and B-glucuronidase, it was observed that quercetin, a vitamin P like compound and ascorbic acid stablise while dehydroascorbate, acetoacetate and B-hydroxybutyrate labilise the leukocytic lysosomes in vitro. These effects were compared with chloroquine and progesterone, known stabiliser and destabiliser, respectively. The possible mode of lysosomal labilisation by ketone bodies and dehydroascorbate has been suggested.