Vasoactive effects of erythropoietin on human placental blood vessels in vitro

Objective: The aim of this study was to investigate the direct effect of erythropoietin on human placental vessels. Study Design: Placental vessel rings (n = 8 for each group) from uncomplicated pregnancies were exposed to recombinant human erythropoietin (10-300 IU/mL) in an isometric myograph. One-way analysis of variance with the Bonferroni posttest was used to evaluate significant levels of differences. Results: Recombinant human erythropoietin evoked reproducible contractions on the vessel rings in a dose-dependent way, which were marked significantly more on veins than on arteries. These contractile responses were not changed by captopril (10−5 mol/L) but were blunted significantly by losartan (10−5 mol/L). Conclusion: We concluded that recombinant human erythropoietin exerts a direct contractile effect on human placental vessels, angiotensin II type 1 receptors are needed to mediate these responses, and erythropoietin might participate in one of the humoral mechanisms that are involved in the control of the human placental vascular bed and also in the pathogenesis of intrauterine growth restriction and preeclampsia.