title: Pulmonary arterial dysfunction in insulin resistant obese Zucker rats.
abstract: BACKGROUND
  Insulin resistance and obesity are strongly associated with systemic cardiovascular diseases. Recent reports have also suggested a link between insulin resistance with pulmonary arterial hypertension. The aim of this study was to analyze pulmonary vascular function in the insulin resistant obese Zucker rat.
  
  
  METHODS
  Large and small pulmonary arteries from obese Zucker rat and their lean counterparts were mounted for isometric tension recording. mRNA and protein expression was measured by RT-PCR or Western blot, respectively. KV currents were recorded in isolated pulmonary artery smooth muscle cells using the patch clamp technique.
  
  
  RESULTS
  Right ventricular wall thickness was similar in obese and lean Zucker rats. Lung BMPR2, KV1.5 and 5-HT2A receptor mRNA and protein expression and KV current density were also similar in the two rat strains. In conductance and resistance pulmonary arteries, the similar relaxant responses to acetylcholine and nitroprusside and unchanged lung eNOS expression revealed a preserved endothelial function. However, in resistance (but not in conductance) pulmonary arteries from obese rats a reduced response to several vasoconstrictor agents (hypoxia, phenylephrine and 5-HT) was observed. The hyporesponsiveness to vasoconstrictors was reversed by L-NAME and prevented by the iNOS inhibitor 1400W.
  
  
  CONCLUSIONS
  In contrast to rat models of type 1 diabetes or other mice models of insulin resistance, the obese Zucker rats did not show any of the characteristic features of pulmonary hypertension but rather a reduced vasoconstrictor response which could be prevented by inhibition of iNOS.
authors.affiliation: Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moral-Sanz
authors.forename: Carmen
authors.initials: C
authors.lastname: Menendez
authors.forename: Laura
authors.initials: L
authors.lastname: Moreno
authors.forename: Enrique
authors.initials: E
authors.lastname: Moreno
authors.forename: Angel
authors.initials: A
authors.lastname: Cogolludo
authors.forename: Francisco
authors.initials: F
authors.lastname: Perez-Vizcaino
mesh_terms: D000818:Animals; D015153:Blotting, Western; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D065627:Familial Primary Pulmonary Hypertension; D006439:Hemodynamics / Q000187:drug effects; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D017380:Hypertrophy, Right Ventricular / Q000209:etiology / Q000503:physiopathology; D007333:Insulin Resistance / Q000235:genetics; D051666:Kv1.5 Potassium Channel / Q000235:genetics / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D009765:Obesity / Q000150:complications* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D018408:Patch-Clamp Techniques; D011651:Pulmonary Artery / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011924:Rats, Zucker; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; C496983:Kcna5 protein, rat; D051666:Kv1.5 Potassium Channel; D012333:RNA, Messenger; D044402:Receptor, Serotonin, 5-HT2A; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; C498220:Bmpr2 protein, rat; D052006:Bone Morphogenetic Protein Receptors, Type II