EXPERIMENTAL STUDY OF TUMOR DIRECTED THERAPY WITH GASTRIC CANCER MONOCLONAL ANTIBODYMITOMYCIN CONJUGATE COMBINED WITH PROPRANOLOL OR ANGIOTENSIN Ⅱ

The effects of vasoactive agents propranolol hydrochloride and angiotensin (AT-Ⅱ) on improving the directed therapy of cancer with the use of conjugate of gastric cancerantibody (3H11) and mitomycin C (MMC) were studied. The antibody activity of the conjugate(3H11-HSA-MMC) was retained with the molecular ratio of 1:2:60. In tests with tumor-bearingnude mice, the tumor inhibitory rate of the conjugate alone was found to be 50%, while in conjugatetreated mice that also received propranolol or AT-II the tumor inhibitory rate were 79% and 60%,respectively. In tumor-bearing nude mice given ¹³¹I-3H11 both propranolol and AT-Ⅱ increased thetumor uptake of ¹³¹I-3H11. These results indicate that these vasoactive agents can change the tissueperfusion ratio via the effect on tumor blood vessels and increase the access of the conjugate to tumor,thereby, enhancing the effectiveness of tumor directed therapy with the use of conjugates.