HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 292/4/H1777    most recent 01024.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Lovering, A. T. Articles by Eldridge, M. W. Search for Related Content PubMed PubMed Citation Articles by Lovering, A. T. Articles by Eldridge, M. W.

Direct demonstration of 25- and 50-µm arteriovenous pathways in healthy human and baboon lungs

¹John Rankin Laboratory of Pulmonary Medicine; and ²Departments of Pediatrics, and ³Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin

Submitted 19 September 2006 ; accepted in final form 27 November 2006

Postmortem microsphere studies in adult human lungs have demonstrated the existence of intrapulmonary arteriovenous pathways using nonphysiological conditions. The aim of the current study was to determine whether large diameter (>25 and 50 µm) intrapulmonary arteriovenous pathways are functional in human and baboon lungs under physiological perfusion and ventilation pressures. We used fresh healthy human donor lungs obtained for transplantion and fresh lungs from baboons (Papio c. anubis). Lungs were ventilated with room air by using a peak inflation pressure of 15 cmH₂O and a positive end-expiratory pressure of 5 cmH₂O. Lungs were perfused between 10 and 20 cmH₂O by using a phosphate-buffered saline solution with 5% albumin. We infused a mixture of 25- and 50-µm microspheres (0.5 and 1 million total for baboons and human studies, respectively) into the pulmonary artery and collected the entire pulmonary venous outflow. Under these conditions, evidence of intrapulmonary arteriovenous anastomoses was found in baboon (n = 3/4) and human (n = 4/6) lungs. In those lungs showing evidence of arteriovenous pathways, 50-µm microspheres were always able to traverse the pulmonary circulation, and the fraction of transpulmonary passage ranged from 0.0003 to 0.42%. These data show that intrapulmonary arteriovenous pathways >50 µm in diameter are functional under physiological ventilation and perfusion pressures in the isolated lung. These pathways provide an alternative conduit for pulmonary blood flow that likely bypasses the areas of gas exchange at the capillary-alveolar interface that could compromise both gas exchange and the ability of the lung to filter out microemboli.

intrapulmonary arteriovenous anastomoses; shunt; baboon; pulmonary circulation

This article has been cited by other articles:

				A. P Rozin Arterio-venous shunts or low oxygen utilization? Human and Experimental Toxicology, February 1, 2010; 29(2): 141 - 144. [Abstract] [PDF]

				A. T. Lovering, M. W. Eldridge, and M. K. Stickland Counterpoint: Exercise-induced intrapulmonary shunting is real J Appl Physiol, September 1, 2009; 107(3): 994 - 997. [Full Text] [PDF]

				Rebuttal from Hopkins, Olfert, and Wagner J Appl Physiol, September 1, 2009; 107(3): 997 - 998. [Full Text] [PDF]

				R. L. Jones, A. W. Sheel, R. Naeije, J. M. B. Hughes, and M. L. Bates Pathophysiological insight into shunted bubbles. J Appl Physiol, September 1, 2009; 107(3): 999 - 1000. [Full Text] [PDF]

				S. R. Hopkins, I. M. Olfert, and P. D. Wagner Point:Counterpoint: Exercise-induced intrapulmonary shunting is imaginary vs. real J Appl Physiol, September 1, 2009; 107(3): 993 - 994. [Full Text] [PDF]

				A. T. Lovering, H. C. Haverkamp, L. M. Romer, J. S. Hokanson, and M. W. Eldridge Transpulmonary passage of 99mTc macroaggregated albumin in healthy humans at rest and during maximal exercise J Appl Physiol, June 1, 2009; 106(6): 1986 - 1992. [Abstract] [Full Text] [PDF]

				A. T. Lovering, M. K. Stickland, M. Amann, J. C. Murphy, M. J. O'Brien, J. S. Hokanson, and M. W. Eldridge Hyperoxia prevents exercise-induced intrapulmonary arteriovenous shunt in healthy humans J. Physiol., September 15, 2008; 586(18): 4559 - 4565. [Abstract] [Full Text] [PDF]

				J. A. Dempsey, D. C. McKenzie, H. C. Haverkamp, and M. W. Eldridge Update in the Understanding of Respiratory Limitations to Exercise Performance in Fit, Active Adults Chest, September 1, 2008; 134(3): 613 - 622. [Abstract] [Full Text] [PDF]

				A. T. Lovering, L. M. Romer, H. C. Haverkamp, D. F. Pegelow, J. S. Hokanson, and M. W. Eldridge Intrapulmonary shunting and pulmonary gas exchange during normoxic and hypoxic exercise in healthy humans J Appl Physiol, May 1, 2008; 104(5): 1418 - 1425. [Abstract] [Full Text] [PDF]

				I. Vogiatzis, S. Zakynthinos, R. Boushel, D. Athanasopoulos, J. A. Guenette, H. Wagner, C. Roussos, and P. D. Wagner The contribution of intrapulmonary shunts to the alveolar-to-arterial oxygen difference during exercise is very small J. Physiol., May 1, 2008; 586(9): 2381 - 2391. [Abstract] [Full Text] [PDF]