Abstract
After oral administration of an organic germanium compound, Ge-132 (300mg/kg), a significant level of interferon (IFN) activity was detected in the sera of mice at 20hr and it reached a maximum of 320U/ml at 24hr. This IFN activity was lost after heat- or acid-treatment, suggesting that the induced IFN is of γ-nature. The molecular weight of this IFN was estimated to be 50, 000 daltons by gel filtration. The NK activity of spleen cells was increased 24hr after the oral administration of Ge-132, and cytotoxic macrophages were induced in the peritoneal cavity by 48hr. In the mice receiving an intraperitoneal (ip) injection of trypan blue or carrageenan 2 days before oral administration of Ge-132, neither induction of IFN nor augmentation of NK activity occurred, and X-ray irradiation of mice also rendered the mice incapable of producing IFN, all indicating that both macrophages and lymphocytes are required for this IFN induction. Both NK and cytotoxic macrophages appeared 18hr after ip administration of the induced IFN with a titer as low as 20U/ml. These facts suggest that both the augmentation of NK activity and activation of macrophages in mice after oral administration of Ge-132 are mediated by the induced IFN.
