The kinetics of interferon clearance in mice: comparison of mouse and human interferon.

Abstract

Mice were injected with three kinds of interferon, i.e., mouse, human leucocyte and human fibroblast interferon, and the kinetics of their clearance from the blood was compared. After intravenous injection, mouse interferon was cleared very rapidly with an initial half life to two to three minutes, while both types of human interferon were cleared rather slowly with a corresponding value of about 20 minutes. When mouse interferon was injected intramuscularly or intraperitoneally, only very low levels of interferon activity were detected in the serum, and the recovery did not exceed 1% at any time. In contrast, both types of human interferon gave appreciable levels of activity in the serum upon injection by the same routes, and the levels remained stable during the observation period. The recovery of human interferon in the blood was about 10-fold that of mouse interferon. Mouse interferon was not inactivated in vitro by incubation with normal mouse serum. Our results suggest the validity of using homologous interferon for studies on the kinetics of interferon clearance in experimental animals.