Differing effects of resibufagenin on cinobufatalin- versus marinobufagenin-induced preeclampsia in a rodent model.

Objective: Previous studies from this laboratory have demonstrated that the bufodienolide, marinobufagenin, causes a syndrome in the pregnant rat that resembles human preeclampsia. Furthermore, marinobufagenin urinary excretion is elevated in approximately 85% of preeclamptic patients. Resibufagenin, an antagonist to marinobufagenin, completely prevents the syndrome (hypertension, proteinuria, and intrauterine growth restriction) if given from early pregnancy.

Study Design: We investigated the effects of another bufodienolide, cinobufatalin, to determine if it, likewise, could induce the rat "preeclamptic" syndrome, which it did. We then examined whether resibufagenin could prevent the syndrome due to cinobufatalin.

Results: Resibufagenin improved hypertension but not proteinuria, and did not prevent uterine growth restriction.

Conclusion: We conclude that more than one bufodienolide may induce the preeclamptic syndrome and that each may require a specific antagonist to prevent (or treat) the syndrome.