Effects of sera and spleen cells isolated from partially hepatectomized rats on the growth of Walker-256 tumour.

Partial hepatectomy induced acceleration of tumour growth when the subcutaneous implantation of the Walker-256 tumour cells was carried out at the same time with the partial hepatectomy. The intravenous injection of serum or spleen cells isolated from partially hepatectomized rats into Walker-256 tumour bearing rats, resulted in a rapid growth of the tumour. 3H-thymidine incorporation into DNA of Walker-256 tumour cells was parallel to the weight of the tumour. Serum and spleen cells isolated from partially hepatectomized rats have the transfer ability, through activated spleen cells, to stimulate DNA synthesis in tumour cells. Serum acid and alkaline deoxyribonucleases activities were increased after partial hepatectomy, and in the serum of tumour bearing rats which received serum or spleen cells obtained from partially hepatectomized rats.