title: Endothelial dysfunction in the human umbilical artery due to preeclampsia can be prevented by sildenafil.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pharmacology, Akdeniz University Medical Faculty, 07070 ntalya, Turkey. dredibe@hotmail.com
authors.forename: Edibe
authors.initials: E
authors.lastname: Karasu
authors.forename: Nurten
authors.initials: N
authors.lastname: Kayacan
authors.forename: Gulay
authors.initials: G
authors.lastname: Sadan
authors.forename: Bora
authors.initials: B
authors.lastname: Dinc
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D006801:Humans; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010069:Oxadiazoles / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology*; D011225:Pre-Eclampsia / Q000188:drug therapy* / Q000503:physiopathology*; D011247:Pregnancy; D011687:Purines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology*; D014469:Umbilical Arteries / Q000187:drug effects* / Q000503:physiopathology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology*; D055815:Young Adult
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D010069:Oxadiazoles; D010879:Piperazines; D011687:Purines; D011810:Quinoxalines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D019331:NG-Nitroarginine Methyl Ester