Relative potency of nitrovasodilators on human placental vessels from normal and preeclamptic pregnancies

The relative potency of glyceryl trinitrate (GTN), sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP) was determined in human placental arteries and veins from normotensive gestants and preeclamptic women. This study demonstrates that the potency of the three nitrovasodilators is similar in normal and preeclamptic pregnancies. GTN and SNP behave as strong vasodilators and were significantly more potent as relaxant of venous than arterial segments. Meanwhile, SNAP was 1 order of magnitude less potent than GTN and SNP and is equally effective in reducing induced tone in arterial or venous segments. These observations suggest that the placental vessels obtained from normotensive and preeclamptic gestants resulted equally sensitive to the relaxant effect of each nitric oxide donor drug, and nitrovasodilators appear to be an interesting option for further clinical research on the prevention and management of preeclampsia.