Abstract
Previous studies suggest that pulmonary prostaglandin metabolism and action change during the newborn period. Indomethacin, a cyclo–oxygenase inhibitor, increases pulmonary artery pressure (Ppa) in perinatal animals. However, indomethacin has no effect on hypoxic and normoxic Ppa in the isolated perfused lungs of 2-3 month old lambs. This study examined the effects of indomethacin on the steady state pulmonary vascular response to graded hypoxia in isolated perfused lungs of 2-4 day old lambs. Lungs were randomly exposed to 3 levels of hypoxia and returned to an inspired O2 tension (PiO2) of 200 torr after each hypoxic stimulus. The mean Ppa +/- SE (torr) at flow = 50 ml/kg·min for control (C) and indomethacin (I) groups were:
In both groups hypoxia (50 and 30) caused an increase in Ppa and vasodilation occurred at 0. Indomethacin enhanced the pressor response (P<.05). Moreover we noted that, in the C group after a first hypoxic exposure, subsequent hypoxic responses were blunted in comparison with the I group (p<.05). These results suggest that, in isolated lungs of 2-4 day old lambs, an initial hypoxic pressor response caused the release of a dilator prostaglandin which attenuated subsequent responses.
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Gordon, J., Tod, M. & Sylvester, J. 1765 THE EFFECTS OF INDOMETHACIN ON THE HYPOXIC VASOPRESSOR RESPONSE IN ISOLATED LUNGS OF NEWBORN LAMBS. Pediatr Res 19, 405 (1985). https://doi.org/10.1203/00006450-198504000-01783
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DOI: https://doi.org/10.1203/00006450-198504000-01783