Diamines and polyamines in DMBA-induced breast carcinoma containing mast cells resistant to compound 48/80

In female rats, mammary carcinoma were induced by DMBA (7,12-dimethylbenz(alpha)anthracene) administration. The activities of histidine and ornithine decarboxylases and the concentrations of histamine, putrescine and polyamines were determined in tumour extracts and urine. In the tumour tissue, formation of histamine and putrescine took place at much higher rates than in normal mammary tissue. Administration of compound 48/80 in doses that mobilized about 70% of histamine contained in the ear failed to release histamine contained in the tumour; 48/80 also failed to produce histological signs of degranulation of the tumour mast cells. It thus appears that these cells are different from mast cells in most normal tissues, a distinction that calls for further study.