RESUMEN
BACKGROUND: Leptin is a potent direct angiogenic factor that stimulates endothelial cell migration and activation in vitro and angiogenesis in vivo. In addition, leptin has been discussed to play an important role in angiogenesis, as it promotes the formation of new blood vessels. PURPOSE: The effect of exogenously administered leptin on the healing process of a full tissue burn wound model. METHODS: Sixty-three Sprague-Dawley male rats were used. Full tissue burn wound was created by electrocautery. The width of the pin was 0.3 cm; its length was 2 cm and was used at the "cut" modulation. Rats were divided into seven groups of nine animals each. Burn wounds were injected with murine recombinant leptin and the rats were sacrificed 3, 7 and 9 days after surgery. Every group had obtained three animals for the three different days of sacrifice. Three different leptin doses of 250 pg/ml, 500 pg/ml and 1000 pg/ml were used in different animal groups (A, B and C). For every one of the three leptin doses used, another animal group was evaluated by using the combined injection of leptin and antileptin (A1, B1, and C1), in order to study the inhibitory effect to the leptin factor. Nine rats were served as controls. These were injected with 0.3 ml water for injection solution and sacrificed at the same time intervals. After sacrifice of the animals, the skin was grossly determined by its appearance, colour and texture. Full thickness burn wounds were dissected for histological examination. A qualitative analysis of angiogenesis in the burn wound was conducted following a standard hematoxylin and eosin stain. The wound tissue samples from each experimental group underwent immunohistochemical evaluation of microvessel density by endothelial cell staining with mouse anti-rat CD 34 monoclonal antibody. RESULTS: The most impressive growth of new blood vessels appeared seven and nine days after treatment with the highest leptin doses. There were no significant differences in microvessel density between the seventh and the ninth postoperative day among different groups treated with leptin. All wounds from the control group, as well as those from animal groups treated with the combined injection of leptin and antileptin did not develop any new vessels. CONCLUSION: Exogenous administration of recombinant leptin increases early tissue angiogenesis in the burn wound level of an experimental animal model.
Asunto(s)
Proteínas Angiogénicas/farmacología , Quemaduras por Electricidad/tratamiento farmacológico , Leptina/farmacología , Neovascularización Fisiológica/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Proteínas Angiogénicas/administración & dosificación , Animales , Quemaduras por Electricidad/patología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Leptina/administración & dosificación , Masculino , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
BACKGROUND: Leptin is a potent direct angiogenic factor that stimulates endothelial cell migration and activation in vitro and angiogenesis in vivo. In addition, leptin has been discussed to play an important role in angiogenesis, as it promotes the formation of new blood vessels. PURPOSE: The effect of exogenously administered leptin on the healing process of a full tissue burn wound model. METHODS: Sixty-three Sprague-Dawley male rats were used. Full tissue burn wound was created by electrocautery. The width of the pin was 0.3 cm; its length was 2 cm and was used at the "cut" modulation. Rats were divided into seven groups of nine animals each. Burn wounds were injected with murine recombinant leptin and the rats were sacrificed 3, 7 and 9 days after surgery. Every group had obtained three animals for the three different days of sacrifice. Three different leptin doses of 250 pg/ml, 500 pg/ml and 1000 pg/ml were used in different animal groups (A, B and C). For every one of the three leptin doses used, another animal group was evaluated by using the combined injection of leptin and antileptin (A1, B1, and C1), in order to study the inhibitory effect to the leptin factor. Nine rats were served as controls. These were injected with 0.3 ml water for injection solution and sacrificed at the same time intervals. After sacrifice of the animals, the skin was grossly determined by its appearance, colour and texture. Full thickness burn wounds were dissected for histological examination. A qualitative analysis of angiogenesis in the burn wound was conducted following a standard hematoxylin and eosin stain. The wound tissue samples from each experimental group underwent immunohistochemical evaluation of microvessel density by endothelial cell staining with mouse anti-rat CD 34 monoclonal antibody. RESULTS: The most impressive growth of new blood vessels appeared seven and nine days after treatment with the highest leptin doses. There were no significant...
INTRODUÇÃO: A leptina é um potente fator angiogênico que estimula a migração e a ativação de células endoteliais in vitro e a angiogênese in vivo. Além disso, a leptina tem sido considerada importante na angiogênese pois ela promove a formação de novos vasos sanguíneos. OBJETIVO: Investigar o efeito da leptina administrada por via exógena no processo de cicatrização em um modelo experimental de queimadura. MÉTODOS: Foram utilizados sessenta e três ratos Sprague-Dawley, machos. A lesão de espessura total da queimadura foi realizada por eletrocautério. O dano tecidual foi de 0.3 cm numa extensão de 2 cm tendo sido empregada o módulo de "corte"do eletrocautéio. Os ratos foram distribuídos em sete grupos de nove animais. As lesões por queimadura receberam leptina recombinante. Os animais foram sacrificados 3, 7 e 9 dias após o ato operatório. Obteve-se três animais de cada grupo nos três períodos estipulados. Três diferentes dosagens de leptina: 250 pg/ml, 500 pg/ml e 1000 pg/ml foram aplicados nos três diferentes grupos (A, B e C). Para cada uma das três dosagens de leptina, outro grupo de animais foi avaliado pelo uso de injeção combinada de leptina e antileptina (A1, B1 e C1) no sentido de investigar o efeito inibitório do fator leptina. Nove ratos serviram de controles. Estes foram submetidos à injeção de 0.3 ml de água e sacrificados nos mesmos intervalos de tempo. Após o sacrifício dos animais, o tegumento foi avaliado por sua aparência, cor e textura. Fragmentos das feridas queimadas foram ressecadas para exame histológico. A análise qualitativa de angiogênese, na ferida queimada, seguia o padrão da coloração de hematoxilina e eosina. Cada fragmento de tecido, de cada grupo experimental, foi submetido à avaliação imunohistoquímica da densidade dos microvasos pela coloração da célula endotelial por anti-rato CD 34 anticorpo monoclonal. RESULTADOS: O desenvolvimento de novos vasos sanguíneos foi mais significativo após sete e nove dias...