The sequential histological and sialomucins histochemical changes in colonic epithelium during the N-methyl-N-nitrosourea (MNU) induced colonic carcinogenesis were studied in female ICR mice. The sialomucin histochemi...The sequential histological and sialomucins histochemical changes in colonic epithelium during the N-methyl-N-nitrosourea (MNU) induced colonic carcinogenesis were studied in female ICR mice. The sialomucin histochemical changes were assessed by use of high iron diamine-alcian blue staining (HID-AB) at PH 2.5. In the untreated controls, the epithelial cells in the distal colon are characterized by a predominance of sulfomucins, and the cells in the proximal site stain for abundant sialomucins, with occasioual sulfomucins in the base of the crypt. The earlier changes detected at the 4th week are focal areas of hyperplasia in which sulfomucins still predominant as in controls. As the experimental progress, the number of lesions with severe dysplasia increase, with carcinoma in situ and invasive carcinoma appeariug from the 10th week. The areas of mild or moderate dysplasia show marked changes in the composition of mucin, characterized by the progressively increased of staining of sialomucins and accompanied in general by a decrease of sulfomucins, similar to those changes described in transitional mucosa (TM) adjacent to colorectal cancer in the human. It is suggested the morphological malignant transformation of colonic epithelium were paralleled qualitatively enhanced sialomucin staining in concert with reduced sulfomucin staining of epithelial cells, providing further evidence that the mucin changes in TM characterized by an increase in sialomucins might reflect early primary premalignant transformation.展开更多
文摘The sequential histological and sialomucins histochemical changes in colonic epithelium during the N-methyl-N-nitrosourea (MNU) induced colonic carcinogenesis were studied in female ICR mice. The sialomucin histochemical changes were assessed by use of high iron diamine-alcian blue staining (HID-AB) at PH 2.5. In the untreated controls, the epithelial cells in the distal colon are characterized by a predominance of sulfomucins, and the cells in the proximal site stain for abundant sialomucins, with occasioual sulfomucins in the base of the crypt. The earlier changes detected at the 4th week are focal areas of hyperplasia in which sulfomucins still predominant as in controls. As the experimental progress, the number of lesions with severe dysplasia increase, with carcinoma in situ and invasive carcinoma appeariug from the 10th week. The areas of mild or moderate dysplasia show marked changes in the composition of mucin, characterized by the progressively increased of staining of sialomucins and accompanied in general by a decrease of sulfomucins, similar to those changes described in transitional mucosa (TM) adjacent to colorectal cancer in the human. It is suggested the morphological malignant transformation of colonic epithelium were paralleled qualitatively enhanced sialomucin staining in concert with reduced sulfomucin staining of epithelial cells, providing further evidence that the mucin changes in TM characterized by an increase in sialomucins might reflect early primary premalignant transformation.
