Experimental investigations on the influence upon the chemical carcinogenesis

Abstract

After ten times monthly, subcutaneous, injections of 30 mg/kg 1,2-dimethylhydrazine (DMH) to Sprague-Dawley-rats, malignant tumors were found in approximately 90% of the animals after a mean induction period of approximately 330 days. Injections were started on the 2nd day of life and maintained during 10 months. 72% of the tumors induced were formed in the colon, 17% were squamous cell carcinomas of the ear duct, adenosarcomas of the kidney and hepatocellular carcinomas were found in 13 and 11% of the animals, respectively. Additional treatment with immunodepressive (cyclophosphamide, methotrexat, hydrocortisone) and immunostimulating substances (BCG, albumin, vitamin A-acid) as well as an enzyme-stimulating agent (Luminal) did not alter incidences and induction periods of tumors. After application of a vegetarian diet, the rate of liver and kidney tumors was diminished significantly and induction periods of intestinal and ear duct tumors increased.

Evaluation of ENU-Induced Gliomas in Rats: Nomenclature, Immunochemistry, and Malignancy

“…Oligodendrogliomas and mixed gliomas are the most commonly described brain tumors (5,9,12,19,23,24,26,32,34,35,37). Other histologic types reported included astrocytomas (5,10,12,17,23,26,32,35), ependymomas (8,9,12,14,21,35), anaplastic or pleomorphic gliomas (11,12,14,16,21,34,35), gliosarcomas (12), glioependymomas (12,23,24), glioblastomas (5,9,21,29,35), spongioblastomas (37), neuroblastomas (10), medulloblastomas (10), and meningiomas (5,10,12,23). Tumors with malignant changes have sometimes been designated by prefixing the tumor type with the term &dquo;anaplastic&dquo; or &dquo;pleomorphic&dquo; (9,…”

Influence of diet on 1,2‐dimethylhydrazine metabolism in rat liver

“…These findings have been confirmed in animal experiments [3][4][5]. In these experiments, 1,2-dimethyIhydrazine (DMH) was often used as a chemical inducer because it produces a high yield of colon carcinomas [6].…”