[Detection of chalones produced by a primary tumor in the blood of mice with Lewis carcinoma].

The substance fraction precipitated in 81% ethanol from blood or tumour tissue of mice with Lewis (3LL) carcinoma on the 13th, 20th and 32nd day after the tumour transplantation is established to inhibit the processes of proliferation in the cell culture of the same tumour. The fraction isolated on the 7th day after transplantation stimulated the proliferation. No inhibition of proliferation was observed when studying the effect of the same fraction isolated on the 13th and 20th day from blood of mice with B-16 melanoma on the 3LL carcinoma. This fact suggests a tissue-specific action of proliferation inhibitors isolated from blood of mice with Lewis 3LL carcinoma and permits considering them as chalones. An assumption is advanced that the primary tumour synthesizing chalones and secreting them into blood can regulate not only its own growth but also the growth of remoted metastases.