Open AccessJournal Article
Cortisol induces perinatal hepatic gluconeogenesis in the lamb.
Reads0
Chats0
TLDR
Onset of gluconeogenesis in the fetus fails to sustain increases in either fetal or postnatal blood glucose concentrations, and there appears to be a transient decline in gluc oneogenesis from lactate, which may be secondary to limited liver oxygen and substrate supply.Abstract:
To examine the influence of a prenatal increase in plasma cortisol concentration on perinatal initiation of hepatic gluconeogenesis, we infused cortisol into seven fetal sheep at 137-140 days gestation. 14C-Lactate provided tracer substrate for estimation of gluconeogenesis. We measured hepatic blood flow using radionuclide-labeled microspheres. After delivery, fetal arterial blood glucose concentration (1.33 +/- 0.4 mmol/l) increased transiently, but returned to fetal levels within 1 h after delivery. Substantial hepatic gluconeogenesis was induced in the fetus after cortisol infusion, averaging 23.4 +/- 12.2 mumol/min/100 g liver (7.8 +/- 4.4 mumol/min/kg fetal weight). Fetal hepatic glucose output was 44.4 +/- 17.7 mumol/min/100 g liver. Hepatic glucose output did not change after delivery; estimated gluconeogenesis decreased immediately, then increased by 6 h after delivery. Lactate supply to the liver fell substantially, from 1.1 +/- 0.4 mmol/min/100 g in the fetus to 0.24 +/- 0.09 at 1 h after delivery. Lactate flux across the liver decreased from 75.3 +/- 23 mumol/min/100 g in the fetus to 20.2 +/- 15.7 at 1 h after delivery. Hepatic lactate flux was significantly related to gluconeogenesis (r = 0.734, P = 0.0001). We conclude that cortisol induces substantial hepatic gluconeogenesis in fetal sheep near term. After delivery, there appears to be a transient decline in gluconeogenesis from lactate, which may be secondary to limited hepatic oxygen and substrate supply. Onset of gluconeogenesis in the fetus fails to sustain increases in either fetal or postnatal blood glucose concentrations.read more
Citations
More filters
Journal ArticleDOI
Glucocorticoids and the preparation for life after birth: are there long-term consequences of the life insurance?
TL;DR: In all species studied so far, there is an increase in the circulating glucocorticoid concentration in the fetus towards term, and the magnitude and timing of this cortisol surge vary between species, as does the precise mechanism by which it occurs.
Journal ArticleDOI
The role of cortisol in preparing the fetus for birth
TL;DR: The glucocorticoids, cortisol and corticosterone, have a unique function in the fetus in inducing a wide range of enzymes before birth that have little or no function during fetal life but on which survival after birth is dependent.
Journal ArticleDOI
Endocrine regulation of fetal growth
TL;DR: Fetal hormones promote growth and development in utero by altering both the metabolism and gene expression of the fetal tissues to ensure that fetal growth rate is commensurate with the nutrient supply and that prepartum maturation occurs in preparation for extrauterine life.
Journal ArticleDOI
Developmental regulation of glucogenesis in the sheep fetus during late gestation
TL;DR: The results show that glucogenesis occurs in fetal sheep during late gestation in conditions in which the fetal plasma concentrations of cortisol and catecholamines are elevated, and suggest that cortisol enhances the capacity for glucogenesis in utero, while catechlamines actually activate glucose production in sheep fetuses close to term.
Journal ArticleDOI
Materno-foetal exchanges and utilisation of nutrients by the foetus: comparison between species
TL;DR: As shown by the high urea level in foetal blood, amino acids are partly involved in the oxidative metabolism of foetuses; their contribution is higher in ruminants than in humans, horses and pigs.