title: Antimetastatic action of RX-RA 69, a new potent PDE-inhibitor in the Lewis lung carcinoma of the mouse.
abstract: 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.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000818:Animals; D002449:Cell Aggregation / Q000187:drug effects; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009374:Neoplasms, Experimental / Q000188:drug therapy; D010974:Platelet Aggregation / Q000187:drug effects; D011743:Pyrimidines / Q000627:therapeutic use*
chemical_list: D011743:Pyrimidines; C035537:RX-RA 69; D015105:3',5'-Cyclic-AMP Phosphodiesterases