Distribution of human recombinant interferon-alpha 2 in rat plasma, liver, and experimental liver metastases.

: It has been ascertained that one of several possible reasons for negligible interferon activity in solid tumors, namely, hepatic metastases induced in rats after intraportal injection of Walker carcinoma 256 cells, is the significantly lower levels of interferon in the interstitial fluid of metastases in comparison to normal liver and plasma.