1, 2-Dimethyl hydrazine 투여후 백서 대장점막 변화에 대한 광학 및 전자현미경적 연구

Abstract

1,2-dimethyl hydrazine·2Hcl(DMH)을 백서에 투여하여 발생된 대장점막 병소는 인간의 대장암과 유사해서 대장암 발생과정을 연구하는 모형이 되고 있다. 이에 저자는 대장암 발생의 초기 형태학적 변화를 관찰하고자 체중 140g정도의 웅성백서(Sprague Dawley)에 DMH20mg/kg 및 40mg/kg을 주1회씩 투여한 후 1, 3, 5, 6, 7, 9, 12, 14, 17, 20주에 도살하여 대장점막에 초래되는 일련의 변화를 광학 및 전자현미경으로 관찰하고 대장조직내 alkaline phosphatase 염색을 하여 조사하여 얻은 결과는 백서에 DMH를 장기간 투여시 초기부터 대장점막에서 세포증식 및 세포분열 증가를 일으키고 장기적으로는 세포이형증 및 상피세포내암과 침습암을 발생시키며, 전자현미경으로도 종양세포와 같은 미세구조의 변화를 관찰할 수 있었다. 이러한 변화는 DMH투여량 증가에 따라 더욱 현저하였다. 상피세포내 alkaline phosphatase는 이형증 및 암발생시 나타나고 암세포로 변화시 더욱 증가되어 종양표식자로 이용될 가능성을 암시할 수 있었다. ; The fact that the administration of 1,2-dimethylhydrazine 2Hcl(DMH) to rats by weekly subcutaneous injections causes the development of epithelial tumors of the large intestine has been known. But the exact processes of early morphologic changes of colonic lesion induced by DMH treatment in the rats have not been fully testified as yet. The objective of the dissertation research is to examine early morphologic changes of colonic lesion induced by DMH treatment in the rats. Total seventy cases including 14 control rats of Sprague Dawley male rats were analyzed by histopathologic changes. One is 20mg/kg/wk DMH treated rat group and the other is 40mg/kg/wk DMH treated rat group. DMH was injected s.c.at the start of each treatment weekly during 20 weeks, and the animals were killed at 1, 3, 5, 6, 7, 9, 12, 14, 17 or 20 weeks both in 20mg/kg/wk DMH treated group and in 40mg/kg/wk DMH treated group. The following results were obtained: Hyperplasia and mitosis of the crypt are presented in early phase of DMH treatment. Cellular dysplasia, carcinoma in situ, and invasive carcinoma are shown in later phase of DMH treatment. The same changes as the above are also identified in electron microscopic findings. The more doses of DMH are injected to rats, the more evident these findings are presented. The alkaline phosphatase activity in glandular epithelial cells are observed in cellular dysplasia and neoplastic changes. The alkaline phosphatase may be considered as tumor marker.