201. Rosiglitazone preserves pulmonary vascular function in lambs with increased pulmonary blood flow.
- Author
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Oishi PE, Sharma S, Datar SA, Kumar S, Aggarwal S, Lu Q, Raff G, Azakie A, Hsu JH, Sajti E, Fratz S, Black SM, and Fineman JR
- Subjects
- Acetylcholine metabolism, Analysis of Variance, Animals, Animals, Newborn, Blotting, Western, Hemodynamics, NADPH Oxidases metabolism, Nitric Oxide administration & dosage, Nitric Oxide pharmacology, PPAR gamma metabolism, Pulmonary Wedge Pressure drug effects, Pulmonary Wedge Pressure physiology, Rosiglitazone, Sheep, Superoxide Dismutase metabolism, Tyrosine analogs & derivatives, Tyrosine metabolism, Vascular Resistance drug effects, Vascular Resistance physiology, rac1 GTP-Binding Protein metabolism, PPAR gamma agonists, Pulmonary Circulation drug effects, Pulmonary Circulation physiology, Thiazolidinediones pharmacology
- Abstract
Background: Pulmonary vascular function is impaired with increased pulmonary blood flow (PBF). We hypothesized that a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist would mitigate this effect., Methods: An aorta-to-pulmonary-artery shunt was placed in 11 fetal lambs. Lambs received the PPAR-γ agonist rosiglitazone (RG, 3 mg/kg/d, n = 6) or vehicle (n = 5) for 4 wk. Lung tissue from five normal 4-wk-old lambs was used for comparisons., Results: At 4 wk, pulmonary artery pressure (PAP) and vascular resistance (PVR) decreased with inhaled nitric oxide (NO) in RG- and vehicle-treated shunt lambs. PAP and PVR decreased with acetylcholine (Ach) in RG-treated, but not vehicle-treated, shunt lambs. In vehicle-treated shunt lambs, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, rac1, superoxide, and 3-nitrotyrosine (3-NT) levels were increased, and Ser1177 endothelial NO synthase (eNOS) protein was decreased as compared with normal lambs. In RG-treated shunt lambs, NOx, Ser1177 eNOS protein, and eNOS activity were increased, and NADPH activity, rac1, superoxide levels, and 3-NT levels were decreased, as compared with vehicle-treated shunt lambs. PPAR-γ protein expression was lower in vehicle-treated shunt lambs than in normal and RG-treated shunt lambs., Conclusion: The PPAR-γ agonist RG prevents the loss of agonist-induced endothelium-dependent pulmonary vascular relaxation in lambs with increased PBF, in part, due to decreased oxidative stress and/or increased NO production.
- Published
- 2013
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