Antenatal fetal VEGF therapy to promote pulmonary maturation in a preterm rabbit model

Aim To assess the effects of fetal tracheal administration of VEGF on pulmonary maturation in a preterm rabbit model Methods: On day 26 (term = 31 days), fetal rabbits received recombinant rat VEGF (30 mu g in 70 mu L normal saline) or placebo (normal saline 70 mu L) intratracheally, with or without subsequent tracheal occlusion. Non-operated littermates served as internal controls. Fetuses were harvested on day 28 for morphometric study of the lungs or for mechanical ventilation and measurement of lung mechanics In total, 96 fetuses from 42 does were used, 47 for ventilation and 49 for morphometry. Results: In fetuses receiving intratracheal VEGF, an increase in immunoreactivity for Flk-1 was observed throughout the lung parenchyma Tracheal occlusion (TO) adversely affected pulmonary mechanics as compared to tin-occluded controls That effect is partly reversed by intratracheal VEGF Intratracheal injection of VEGF without tracheal occlusion improves lung mechanics but no more than what was observed in placebo injected controls. Conclusion Antenatal intratracheal VEGF administration was associated with an increase in Flk-1 immunoreactivity It also improves lung mechanics, however more so when the trachea is occluded Without TO, the effects were comparable to placebo controls (C) 2010 Elsevier Ireland Ltd. All rights reserved