Optimization of isolated perfused/ventilated mouse lung to study hypoxic pulmonary vasoconstriction

Hae Young Yoo, Amy Zeifman, Eun A. Ko, Kimberly A. Smith, Jiwang Chen, Roberto Machado, You Yang Zhao, Richard D. Minshall, Jason X.J. Yuan

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Hypoxic pulmonary vasoconstriction (HPV) is a compensatory physiological mechanism in the lung that optimizes the matching of ventilation to perfusion and thereby maximizes gas exchange. Historically, HPV has been primarily studied in isolated perfused/ ventilated lungs; however, the results of these studies have varied greatly due to different experimental conditions and species. Therefore, in the present study, we utilized the mouse isolated perfused/ventilated lung model for investigation of the role of extracellular Ca2+and caveolin-1 and endothelial nitric oxide synthase expression on HPV. We also compared HPV using different perfusate solutions: Physiological salt solution (PSS) with albumin, Ficoll, rat blood, fetal bovine serum (FBS), or Dulbecco’s Modified Eagle Medium (DMEM). After stabilization of the pulmonary arterial pressure (PAP), hypoxic (1% O2) and normoxic (21% O2) gases were applied via a ventilator in five-minute intervals to measure HPV. The addition of albumin or Ficoll with PSS did not induce persistent and strong HPV with or without a pretone agent. DMEM with the inclusion of FBS in the perfusate induced strong HPV in the first hypoxic challenge, but the HPV was neither persistent nor repetitive. PSS with rat blood only induced a small increase in HPV amplitude. Persistent and repetitive HPV occurred with PSS with 20% FBS as perfusate. HPV was significantly decreased by the removal of extracellular Ca2+along with addition of 1 mM EGTA to chelate residual Ca2+and voltage-dependent Ca2+channel blocker (nifedipine 1 μM). PAP was also reactive to contractile stimulation by high K+depolarization and U46619 (a stable analogue of thromboxane A2). In summary, optimal conditions for measuring HPV were established in the isolated perfused/ventilated mouse lung. Using this method, we further confirmed that HPV is dependent on Ca2+influx.

Original languageEnglish (US)
Pages (from-to)396-405
Number of pages10
JournalPulmonary Circulation
Volume3
Issue number2
DOIs
StatePublished - Apr 1 2013
Externally publishedYes

Keywords

  • Endothelial nitric oxide synthase
  • Hypoxia
  • Mouse lung
  • Pulmonary artery
  • Pulmonary vasoconstriction

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

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  • Cite this

    Yoo, H. Y., Zeifman, A., Ko, E. A., Smith, K. A., Chen, J., Machado, R., Zhao, Y. Y., Minshall, R. D., & Yuan, J. X. J. (2013). Optimization of isolated perfused/ventilated mouse lung to study hypoxic pulmonary vasoconstriction. Pulmonary Circulation, 3(2), 396-405. https://doi.org/10.4103/2045-8932.114776