Potentiation by dipyridamole of 5-fluorouridine antitumor activity against a rat adenocarcinoma in vivo.

Rats were inoculated subcutaneously into both flanks with a transplantable adenocarcinoma of the colon. They were treated intravenously with either 5-FUrd (5-fluorouridine) or 5-FdUrd (5-fluoro-2'-deoxyuridine) with or without addition of dipyridamole 20 and 30 min later, respectively, for 3 consecutive days. Dipyridamole improved the antitumor activity of 5-FUrd but decreased that of 5-FdUrd.