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Endothelial dysfunction in the human umbilical artery due to preeclampsia can be prevented by sildenafil
Edibe Karasu1, Nurten Kayacan, Gulay Sadan
1Department of Pharmacology, Akdeniz University Medical Faculty, 07070 ntalya, Turkey. dredibe@hotmail.com
Objectives:
We aimed to determine the effects of sildenafil in human umbilical artery preparation taken from preeclamptic or normal pregnant women, also to investigate underlying mechanisms in these effects.
Study Design:
Eighteen pregnant women with preeclampsia and 18 healthy pregnant women were involved. Relaxation responses of sildenafil in presence and absence of nitric oxide (NO) synthase inhibitor, N-[omega]-nitro-L-arginine methyl ester (L-NAME), and soluble guanylyl cyclase inhibitor, 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ), were compared between the preeclampsia group and control group.
Results:
Sildenafil-induced relaxation responses were significantly attenuated in the presence of preeclampsia, L-NAME or ODQ, but not totally abolished. Interestingly, except with ODQ incubation, in all set of experiments maximal relaxation response was achieved by sildenafil.
Conclusion:
These data indicate that sildenafil might effect vascular responsiveness of human umbilical artery through the involvement of NO/cyclic guanosine monophosphate (cGMP)-dependent and -independent pathways. Further investigations are needed to clarify the exact mechanisms.
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