Experimental rat lung tumor model with intrabronchial tumor cell implantation

ABSTRACT

PURPOSE: The objective of this study was to develop a rat lung tumor model for anticancer drug testing. METHODS: Sixty-two female Wistar rats weighing 208 ± 20 g were anesthetized intraperitoneally with 2.5 percent tribromoethanol (1 ml/100 g live weight), tracheotomized and intubated with an ultrafine catheter for inoculation with Walker's tumor cells. In the first step of the experiment, a technique was established for intrabronchial implantation of 10(5) to 5×10(5) tumor cells, and the tumor take rate was determined. The second stage consisted of determining tumor volume, correlating findings from high-resolution computed tomography (HRCT) with findings from necropsia and determining time of survival. RESULTS: The tumor take rate was 94.7 percent for implants with 4×10(5) tumor cells, HRCT and necropsia findings matched closely (r=0.953; p<0.0001), the median time of survival was 11 days, and surgical mortality was 4.8 percent. CONCLUSION: The present rat lung tumor model was shown to be feasible: the take rate was high, surgical mortality was negligible and the procedure was simple to perform and easily reproduced. HRCT was found to be a highly accurate tool for tumor diagnosis, localization and measurement and may be recommended for monitoring tumor growth in this model.

RESUMO

OBJETIVO: O objetivo foi desenvolver um modelo de tumor de pulmão em rato que permita o teste de fármacos no tratamento deste câncer. MÉTODOS: Sessenta e dois ratos Wistar fêmeas, peso médio de 208±20 g, foram anestesiados com tribromo-etanol 2,5 por cento IP (1ml/100g de rato), traqueostomizados e intubados com cateter ultrafino para injetar células do tumor de Walker. Na 1ª etapa, estabeleceu-se a técnica do implante de células tumorais por via intrabrônquica e o índice de pega tumoral, usando-se de 10(5) a 5×10(5) células. Na 2ª, avaliou-se o volume tumoral e a correlação dos achados obtidos na tomografia computadorizada de alta resolução (TCAR) de tórax com os da necropsia e verificou-se a sobrevida. RESULTADOS: O índice de pega foi de 94,7, com o implante de 4×10(5) células do tumor; as medidas do tumor feitas na TCAR e comparadas com as da necropsia foram semelhantes (r=0, 953, p<0,0001); a sobrevida mediana foi de 11 dias; e a mortalidade cirúrgica de 4,8 por cento. CONCLUSÃO: O modelo mostrou-se viável, com alto índice de pega, mortalidade cirúrgica desprezível, de execução simples e fácil reprodutibilidade. A TCAR revelou alta acurácia no diagnóstico, localização e mensuração das lesões tumorais, credenciando-se para a monitorização de crescimento tumoral nesse modelo.