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This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 102/3/1281    most recent 00632.2006v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI 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 ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Glenny, R. W. Articles by Polissar, N. L. Search for Related Content PubMed PubMed Citation Articles by Glenny, R. W. Articles by Polissar, N. L.

HIGHLIGHTED TOPIC
Physiological Imaging of the Lung

The spatial-temporal redistribution of pulmonary blood flow with postnatal growth

¹School of Medicine, Division of Pulmonary and Critical Care Medicine; Departments of ²Physiology and Biophysics and ³Environmental and Occupational Health Sciences, University of Washington, Seattle; ⁴Mountain-Whisper-Light Statistical Consulting, Seattle, Washington

Submitted 7 June 2006 ; accepted in final form 6 November 2006

The pulmonary vascular tree undergoes remarkable postnatal development and remodeling. While a number of studies have characterized longitudinal changes in vascular function with growth, none have explored regional patterns of vascular remodeling. We therefore studied six neonatal pigs to see how regional blood flow changes with growth. We selected pigs because of their rapid growth and their similarities to human development with respect to the pulmonary vascular tree. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood on days 3, 12, 27, 43, and 71 after birth. The animals were awake and in the prone posture for all injections. The lungs were subsequently removed, air dried, and sectioned into 2-cm³ pieces. Flow on each injection day was determined for each piece. Despite the increase in the hydrostatic gradient in the lung with growth, there was a strong correlation between blood flow to the same lung piece when compared on days 3 and 71 (0.73 ± 0.12). Although a dorsal-ventral gradient of perfusion did not exist on day 3, blood flow increased more in the dorsal region by day 12 and then gradually became more uniform by day 71. Although most of the lung pieces did not show any discernable pattern of blood flow redistribution, there were spatial patterns of blood flow redistribution that were similar across animals. Our findings suggest that local mechanisms, shared across animals, guide regional changes in vascular resistance or vasoregulation during postnatal development. In the pig, these mechanisms act to produce more uniform flow in the normal posture for an ambulating quadruped. The stimuli for these changes have not yet been identified.

blood flow distribution; remodeling; vertical gradient

This article has been cited by other articles:

				R. Glenny Counterpoint: Gravity is not the major factor determining the distribution of blood flow in the healthy human lung J Appl Physiol, May 1, 2008; 104(5): 1533 - 1535. [Full Text] [PDF]