The impact of reduced nutrition on growth and cardiovascular control in the fetus
The impact of reduced nutrition on growth and cardiovascular control in the fetus
In the first study, late gestation sheep fetuses underwent sham surgery (S) or carotid sinus denervation (D). The ewes were then exposed to 3 weeks control diet or 50 % nutrient restriction. Liver and adrenal sizes were positively and negatively related to ewe weight gain, respectively, in S but not D fetuses.
In the subsequent studies, ewes received 100 % (C), 50 % (R50) or 40 % (R40) of total nutrient requirements from 1 to 31 days of gestation (dGA, term = 147 dGA), and 100 % of requirements thereafter. In late gestation chronic fetal preparations, acute hypoglycaemia was induced by maternal insulin infusion. During hypoglycaemia, fetal femoral and left liver arterial blood flow fell, fetal heart rate fell, and fetal adrenal blood flow increased. These changes were accompanied by increased fetal plasma adrenaline and cortisol. The maximum fall in femoral artery flow was faster in R than C fetuses. In R40 fetuses, basal heart rate and the time spent in high voltage ECoG activity was greater during hypoglycaemia than in C fetuses. A late gestation 50 % maternal nutrient restriction did not produce comprehensive CV measurement alterations, but did reduce the ability of the fetus to survive surgery. The investigation of the fetal CB response to low glucose in vitro was inconclusive.
These studies demonstrate redistribution of fetal nutritional resources during reduced nutrient supply, and suggest that differential organ growth is mediated at least in part by CV responses. The carotid body is implicated in nutrient detection in fetal life.
University of Southampton
2006
Burrage, Deborah
(2006)
The impact of reduced nutrition on growth and cardiovascular control in the fetus.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
In the first study, late gestation sheep fetuses underwent sham surgery (S) or carotid sinus denervation (D). The ewes were then exposed to 3 weeks control diet or 50 % nutrient restriction. Liver and adrenal sizes were positively and negatively related to ewe weight gain, respectively, in S but not D fetuses.
In the subsequent studies, ewes received 100 % (C), 50 % (R50) or 40 % (R40) of total nutrient requirements from 1 to 31 days of gestation (dGA, term = 147 dGA), and 100 % of requirements thereafter. In late gestation chronic fetal preparations, acute hypoglycaemia was induced by maternal insulin infusion. During hypoglycaemia, fetal femoral and left liver arterial blood flow fell, fetal heart rate fell, and fetal adrenal blood flow increased. These changes were accompanied by increased fetal plasma adrenaline and cortisol. The maximum fall in femoral artery flow was faster in R than C fetuses. In R40 fetuses, basal heart rate and the time spent in high voltage ECoG activity was greater during hypoglycaemia than in C fetuses. A late gestation 50 % maternal nutrient restriction did not produce comprehensive CV measurement alterations, but did reduce the ability of the fetus to survive surgery. The investigation of the fetal CB response to low glucose in vitro was inconclusive.
These studies demonstrate redistribution of fetal nutritional resources during reduced nutrient supply, and suggest that differential organ growth is mediated at least in part by CV responses. The carotid body is implicated in nutrient detection in fetal life.
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Published date: 2006
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Local EPrints ID: 465962
URI: http://eprints.soton.ac.uk/id/eprint/465962
PURE UUID: 090b7e9f-336c-4bfd-a0a3-527026999c83
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Date deposited: 05 Jul 2022 03:47
Last modified: 05 Jul 2022 03:47
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Author:
Deborah Burrage
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