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The effects of graded levels of dietary carbohydrate on fetal and neonatal glucose metabolism

The effects of maternal dietary glucose restriction on reproductive performance were investigated by feeding pregnant rats isocaloric diets containing graded levels of dietary glucose (0, 12, 24 and 60%) during pregnancy and during pregnancy and lactation, and by measuring the effects of glucose restriction on (1) maternal, fetal and neonatal metabolism, on (2) growth and composition of the mammary glands and placentas, and (3) on milk composition. Carbohydrate restriction induced maternal metabolic adaptations that were proportional to the severity of the glucose restriction. Placental growth and composition as well as mammary gland composition were not affected by dietary glucose restriction, whereas fetal growth and development and milk composition were significantly impaired when glucose was limited in the maternal diet. This suggests that the effects of dietary glucose on the fetus and on milk composition were not mediated by changes in placenta and mammary gland DNA, protein or glycogen concentrations. Complete dietary glucose restriction significantly depressed fetal liver, lung and heart glycogen concentrations; repletion of the maternal diets with 12 and 24% glucose restored cardiac glycogen to normal but not fetal lung glycogen and liver glycogen. Pups born to dams fed a glucose-free diet failed to survive longer than 24 h postpartum and that was associated with the low levels of tissue glycogen at birth in these pups. At birth, lung and liver glycogen concentration of pups of the 12 and 24% glucose diets was similar to pups of the control diet despite the fact that these reserves were depressed in utero; and these pups efficiently corrected the transient hypoglycemia observed following parturition. The effects of glucose restriction on fetal liver glycogen were not reflected by similar changes in fetal plasma insulin, glucagon and glucose levels or in glycogen synthase and phosphorylase activities. Maternal dietary glucose was an important determinant

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41670
Date January 1993
CreatorsLanoue, Louise
ContributorsKoski, Kristine G. (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageDoctor of Philosophy (School of Dietetics and Human Nutrition.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001385066, proquestno: NN94662, Theses scanned by UMI/ProQuest.

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