Lichtner R, Haarmann W
Prog Clin Biol Res. 1982;89:131-41.
RX-RA 69, a pyrimido-pyrimidine derivative, is a new potent PDA-inhibitor which inhibits tumor cell induced platelet aggregation in vitro. Also ex vivo an inhibition was found after pretreating mice with 1 mg/kg RX-RA 69 orally one hour before collecting the blood. The same dosage is able to prevent the drop in platelet count induced by injecting a large number of tumor cells into mice. The same dosage schedule in the amputation experiment resulted in a reduction of incidence of matastases in all treated groups; the best results, however, were obtained by starting the treatment two days after the amputation. In the spontaneous model an inhibition of metastases formation by 10-20 mg/kg RX-RA 69 starting from the fourth day after tumor cell implantation was found in four independent experiments. The mechanism of the antimetastatic action of this drug remains to be evaluated.
RX - RA 69是一种嘧啶并嘧啶衍生物，是一种新型强效PDA抑制剂，可在体外抑制肿瘤细胞诱导的血小板聚集。在对小鼠进行体内实验时，于采血前1小时口服1 mg/kg的RX - RA 69进行预处理后，也发现了抑制作用。相同剂量能够预防因向小鼠注射大量肿瘤细胞而导致的血小板计数下降。在截肢实验中，相同的给药方案使所有治疗组的转移发生率降低；然而，最佳结果是在截肢后两天开始治疗获得的。在自发模型中，在四项独立实验中发现，从肿瘤细胞植入后第四天开始，10 - 20 mg/kg的RX - RA 69可抑制转移形成。该药物的抗转移作用机制仍有待评估。
