Lysosomal enzymes in macrophages of colonic tumors induced in rats by 1,2-dimethylhydrazine dihydrochloride.
Ten weekly doses of dimethylhydrazine (30 mg/kg) were given to rats to induce colonic tumors. Histochemical and electron cytochemical studies revealed a distinct pattern of lysosomal acid phosphatase and beta-glucuronidase activity in macrophages in the stroma of these neoplasms. A dramatic increase in the number of acid phosphatase-rich macrophages was present in adenomas when compared to that in normal colonic mucosa. Fewer numbers of these cells were seen in well-differentiated adenocarcinomas, and they were barely detectable in highly invasive mucinous adenocarcinomas. It is postulated that these macrophages may play a role in preventing the invasion of adenomatous neoplasms into the submucosa. Application of histochemical techniques to study macrophage lysosomal enzymes may prove a useful diagnostic tool in differentiation of human colonic tumors for prognostic evaluation.
D000135:Acid Phosphatase / Q000378:metabolism*; D000230:Adenocarcinoma / Q000139:chemically induced / Q000201:enzymology*; D002288:Adenocarcinoma, Mucinous / Q000139:chemically induced / Q000201:enzymology*; D000236:Adenoma / Q000139:chemically induced / Q000201:enzymology*; D000818:Animals; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000201:enzymology*; D004127:Dimethylhydrazines; D005966:Glucuronidase / Q000378:metabolism*; D008247:Lysosomes / Q000201:enzymology*; D008264:Macrophages / Q000201:enzymology*; D008297:Male; D008763:Methylhydrazines; D009374:Neoplasms, Experimental / Q000201:enzymology; D051381:Rats
D004127:Dimethylhydrazines; D008763:Methylhydrazines; D000135:Acid Phosphatase; D005966:Glucuronidase