The effects of an antimetastatic agent, (plus or minus)-1,2-bis(3,5-dioxopiperazin-1-yl)propane (ICRF 159), on platelet behavior.

Some agents that inhibit platelet aggregation, e.g., aspirin and dipyridamole, ahve been reported to prevent metastasis formation. To see whether inhibition of platelet aggregation could account for the antimetastatic action of (plus or minus)-1,2- bis(3,5-dioxopiperazin-1-yl)propane, this compound was investigated in vivo for any effects on platelet behavior and thrombogenesis. (plus or minus)-1,2-Bis(3,5-dioxopiperazin-1-yl)propane inhibited the formation of platelet thrombi in blood vessels on the surface of the rat brain and in the hamster cheek pouch. 1,2-Bis(dioxo-4-methylpiperazin-1-yl)ethane, a closely related analog of (plus or minus)-1,2-bis(3,5-dioxopiperazin-1-yl)propane, but without antimetastatic action, inhibited thrombus formation in vivo as effectively as (plus or minus)-1,2-bis(3,5-dioxopiperazin-1-yl)propane. It seems unlikely therefore that the antimetastatic action of (plus or minus)-1,2-bis(3,5-dioxopiperazine-l-yl)propane derives from its effects on thrombogenesis. Neither platelet numbers nor the ionized plasma calcium concentrations were changed after (plus or minus)-1,2-bis(3,5-dioxopiperazin-l-yl)propane administration.