Wound healing and colon carcinogenesis. Enhancing effects of skin wounding on development of colon tumors induced by 1,2 Dimethylhydrazine in the rat
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Data
2000-09-01
Autores
Sequeira, Julio Lopes [UNESP]
Kobayasi, Shoiti [UNESP]
Rodrigues, Maria Aparecida Marchesan [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Resumo
Este estudo foi desenvolvido com a finalidade de investigar a possível influência do processo de cicatrização sobre o desenvolvimento neoplásico à distância, em um modelo experimental de carcinogênese do colon induzido pela 1,2 dimetil-hidrazina ( DMH). Ratos Wistar machos receberam injeções semanais de DMH ( 20mg/Kg, via subcutânea) ou solução salina, durante oito semanas. Na nona semana, um grupo tratado com DMH e um controle, foram submetidos à intervenção cirúrgica para retirada de um retalho cutâneo de 4cm no flanco direito, que cicatrizou por segunda intenção. Na 12ª semana, logo após o fechamento da ferida cutânea, os animais foram submetidos à eutanásia. O colon foi dividido em segmentos proximal e distal e examinado a nível macroscópico e histológico. Foram analisadas a incidência, distribuição e morfologia das lesões. O número total de tumores na mucosa do colon e o número de tumores por animal foi significantimente maior no grupo submetido à ferida cutânea do que no grupo tratado somente com DMH. O número de carcinomas pouco diferenciados foi significantimente maior no grupo com ferida cutânea do que em seu respectivo controle. Estes resultados sugerem que o processo de reparação de uma ferida cutânea favorece o desenvolvimento neoplásico em um órgão à distância, tal como o colon e que este efeito parece estar relacionado ao tipo histológico da neoplasia.
This study demonstrates the tumor promoting effect at a distant site of skin wounding, in a model of colon carcinogenesis induced by 1,2 dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH, 20mg/kg, or saline, once a week, for eight weeks. One week after the last DMH injection the animals received a full thickness skin wound in their dorsal skin and the wound was left open to heal by second intention. Control and DMH-treated rats, with or without skin wounds were killed at the 12th week, just after healing of the skin wound was complete. The colons were removed and divided into proximal and distal parts. Each segment was rolled as Swiss rolland processed for histology. The incidence, distribution and morphology of the colon tumors was recorded. The total number of tumors in the colonic mucosa and the number of tumors per rat was significantly higher in the skin-wounding DMH- treated group than in the unwounded group. In the histopathological analysis of the colon the number of poorly differentiated mucin-secreting carcinomas was 6-fold in the skin-wounding DMH-treated group than in the unwounded group and the majority of tumors were located near to lymphoid aggregates. The present results suggest that wound healing enhances tumor development at a distant site, such as the colon, and this effect seems to be related to tumor histology.
This study demonstrates the tumor promoting effect at a distant site of skin wounding, in a model of colon carcinogenesis induced by 1,2 dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH, 20mg/kg, or saline, once a week, for eight weeks. One week after the last DMH injection the animals received a full thickness skin wound in their dorsal skin and the wound was left open to heal by second intention. Control and DMH-treated rats, with or without skin wounds were killed at the 12th week, just after healing of the skin wound was complete. The colons were removed and divided into proximal and distal parts. Each segment was rolled as Swiss rolland processed for histology. The incidence, distribution and morphology of the colon tumors was recorded. The total number of tumors in the colonic mucosa and the number of tumors per rat was significantly higher in the skin-wounding DMH- treated group than in the unwounded group. In the histopathological analysis of the colon the number of poorly differentiated mucin-secreting carcinomas was 6-fold in the skin-wounding DMH-treated group than in the unwounded group and the majority of tumors were located near to lymphoid aggregates. The present results suggest that wound healing enhances tumor development at a distant site, such as the colon, and this effect seems to be related to tumor histology.
Descrição
Palavras-chave
Cicatrização de feridas, Cólon, 1,2 dimetil-hidrazina, Ratos, Carcinógenos, Wound healing, Colonic neoplasms, 1,2 dimethylhydrazine, Rats, Carcinogens
Como citar
Acta Cirúrgica Brasileira. Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, v. 15, n. 3, p. 00-00, 2000.