African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12496

Full Length Research Paper

Structural changes and effect of denopamine on alveolar fluid clearance in hypoxic rat lungs

Nai-jing Li1, Wei Li2, Xiu Gu3, Ping He1* and Sheng-qi Li3
1Department of Gerontology, Shengjing Affiliated Hospital, China Medical University, Liaoning Province, PR China. 2College of Pharmacy, Shenyang Pharmaceutical University, Liaoning Province, PR China. 3Department of Respiratory Medicine, Shengjing Affiliated Hospital, China Medical University, Liaoning Province, PR China.
Email: [email protected]

  •  Accepted: 02 July 2010
  •  Published: 13 September 2010

Abstract

Terbutaline (β2-adrenergic agonist) can increase alveolar fluid clearance (AFC) under physiologic and pathologic conditions. It is unknown whether β1-adrenergic agonists also increase AFC under pathologic conditions. The aim of this study was to investigate the effect of denopamine (β1- adrenergic agonist ) on AFC in hypoxic lung injury and the possible mechanisms involved. Hypoxic rats were exposed to 10% oxygen. 10-5 mol/L denopamine alone or combined with β receptor antagonists, Na+ channel blocker, or Na+/K+-ATPase blocker were perfused into the alveolar space of rats exposed to 10% oxygen for 48 h. AFC and total lung water content (TLW) were measured. AFC did not change for the first 24 h but then decreased after 48h exposure to 10% oxygen. The perfusion of denopamine significantly increased AFC in normoxic and hypoxic rats. The AFC- stimulating effect of denopamine lowered with amiloride (a Nachannel blocker) and ouabain (a Na+/K+-ATPase inhibitor) by 35 and 53%, respectively. Colchicine significantly inhibited the effect of denopamine. Denopamine can increase the AFC during hypoxic lung injury in rats and accelerate the absorption of pulmonary edema.

 

Key words: β1-Adrenergic agonist, hypoxia, pulmonary edema, alveolar epithelium.