title: Cinaciguat, a soluble guanylate cyclase activator, causes potent and sustained pulmonary vasodilation in the ovine fetus.
abstract: Impaired nitric oxide-cGMP signaling contributes to severe pulmonary hypertension after birth, which may in part be due to decreased soluble guanylate cyclase (sGC) activity. Cinaciguat (BAY 58-2667) is a novel sGC activator that causes vasodilation, even in the presence of oxidized heme or heme-free sGC, but its hemodynamic effects have not been studied in the perinatal lung. We performed surgery on eight fetal (126 +/- 2 days gestation) lambs (full term = 147 days) and placed catheters in the main pulmonary artery, aorta, and left atrium to measure pressures. An ultrasonic flow transducer was placed on the left pulmonary artery to measure blood flow, and a catheter was placed in the left pulmonary artery for drug infusion. Cinaciguat (0.1-100 microg over 10 min) caused dose-related increases in pulmonary blood flow greater than fourfold above baseline and reduced pulmonary vascular resistance by 80%. Treatment with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an sGC-oxidizing inhibitor, enhanced cinaciguat-induced pulmonary vasodilation by >120%. The pulmonary vasodilator effect of cinaciguat was prolonged, decreasing pulmonary vascular resistance for >1.5 h after brief infusion. In vitro stimulation of ovine fetal pulmonary artery smooth muscle cells with cinaciguat after ODQ treatment resulted in a 14-fold increase in cGMP compared with non-ODQ-treated cells. We conclude that cinaciguat causes potent and sustained fetal pulmonary vasodilation that is augmented in the presence of oxidized sGC and speculate that cinaciguat may have therapeutic potential for severe neonatal pulmonary hypertension.
authors.affiliation: Pediatric Heart Lung Center, Department of Pediatrics, University of Colorado School of Medicine, Aurora, 80045, USA. vududoc@aol.com
authors.forename: Marc
authors.initials: M
authors.lastname: Chester
authors.forename: Pierre
authors.initials: P
authors.lastname: Tourneux
authors.forename: Greg
authors.initials: G
authors.lastname: Seedorf
authors.forename: Theresa R
authors.initials: TR
authors.lastname: Grover
authors.forename: Jason
authors.initials: J
authors.lastname: Gien
authors.forename: Steven H
authors.initials: SH
authors.lastname: Abman
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001565:Benzoates / Q000494:pharmacology*; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000187:drug effects / Q000502:physiology; D005865:Gestational Age; D006162:Guanylate Cyclase / Q000378:metabolism*; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000196:embryology; D009569:Nitric Oxide / Q000378:metabolism; D010069:Oxadiazoles / Q000494:pharmacology; D011247:Pregnancy; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000196:embryology; D011652:Pulmonary Circulation / Q000187:drug effects* / Q000502:physiology; D011669:Pulmonary Wedge Pressure / Q000187:drug effects / Q000502:physiology; D011810:Quinoxalines / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists* / Q000378:metabolism*; D012756:Sheep; D000071756:Soluble Guanylyl Cyclase; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D001565:Benzoates; D004791:Enzyme Inhibitors; D010069:Oxadiazoles; D011810:Quinoxalines; D018160:Receptors, Cytoplasmic and Nuclear; D014665:Vasodilator Agents; D009569:Nitric Oxide; C480588:BAY 58-2667; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP; D000109:Acetylcholine