No evidence for an enhanced role of endothelial nitric oxide in the maintenance of arterial blood pressure in the IUGR sheep fetus
Date
2009
Authors
Dyer, J.L.
McMillen, I.C.
Warnes, K.E.
Morrison, J.L.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Placenta, 2009; 30(8):705-710
Statement of Responsibility
Conference Name
Abstract
The fetus makes a number of physiological adaptations to a restriction of placental substrate supply, including a decrease in body growth and an increase in peripheral vasoconstriction which maintains mean arterial pressure (MAP) and supports a redistribution of cardiac output to key fetal organs. It is not known, however, whether chronic restriction of placental substrate supply results in an enhanced or diminished role for vasodilators such as endothelial nitric oxide in the regulation of MAP. We hypothesised that there is an increased contribution of NO to blood pressure regulation in growth restricted fetuses and that a 2 h infusion of a nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME) would result in an augmented rise in MAP in chronically hypoxemic, placentally restricted (PR, n ¼ 8) fetuses compared to controls (n ¼ 6) in late gestation. There was no difference in the increase in fetal MAP and decrease in HR during L-NAME infusion between Control and PR fetuses. In the PR group, fetuses with lower mean gestational PaO2 had a lower increase in MAP during L-NAME infusion. Thus we have found no evidence for an enhanced role of NO in the maintenance of MAP in the chronically hypoxemic IUGR fetus.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
Copyright 2009 Elsevier