Abstract
Serum haptoglobin (Hp) levels were determined periodically in mice treated with the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). The magnitude and duration of the Hp response to tumors induced by DMBA were dependent on the tumor type; lymphocytic lymphomas elicited a minimal response, whereas mice bearing mammary carcinomas and stomach squamous cell carcinomas had high Hp levels which remained elevated throughout most of the period of tumor development. In the majority of mice with mammary carcinomas, the initial rise in serum Hp coincided fairly closely with the first appearance of palpable masses. Some variation in the magnitude ot the Hp response was observed between individual mice bearing chemically-induced tumors of similar histological types.