Study of the antitumor effect of Ukrain: The role of macrophage secretion of alpha-1-proteinase inhibitor

The positive antitumor effect of Ukrain was shown following i.m. injection of a mixture of this drug with Krebs-2 carcinoma cells to CBA mice. The pro tective effect was suggested to be a result of the influx of macrophages in to the site of Ukrain injection. In contrast, contralateral administration of Ukrain had a negative effect, confirming our hypothesis that Ukrain attr acts cytolytic macrophages. In the murine HA-1 hepatoma model treated by si ngle or repeated Ukrain injections, a moderate positive effect of Ukrain wa s related to increased macrophage alpha-1-proteinase inhibitor (PI) secreti on. The role of tumor cells and macrophages in the secretion of PI (the mai n inhibitor of serine proteinases) during tumor development is discussed.