Adaptations of glucose and fatty acid metabolism during perinatal period and suckling-weaning transition

J Girard, P Ferre, JP Pegorier… - Physiological …, 1992 - journals.physiology.org
J Girard, P Ferre, JP Pegorier, PH Duee
Physiological reviews, 1992journals.physiology.org
I. INTRODUCTION hydrate diet. The expansion of the lungs and the establishment of
pulmonary ventilation are of crucial rele-The perinatal period is attended by important
modifications in several physiological functions and particularly dramatic changes of
nutrition. In utero, the fetus receives a continuous intravenous supply of substrates for growth
and oxidative metabolism and produces large quantities of heat, carbon dioxide, and urea
(45, 46). The byproducts of fetal metabolism are efficiently dissipated into the maternal …
I. INTRODUCTION hydrate diet. The expansion of the lungs and the establishment of pulmonary ventilation are of crucial rele-The perinatal period is attended by important modifications in several physiological functions and particularly dramatic changes of nutrition. In utero, the fetus receives a continuous intravenous supply of substrates for growth and oxidative metabolism and produces large quantities of heat, carbon dioxide, and urea (45, 46). The byproducts of fetal metabolism are efficiently dissipated into the maternal organism across the placenta (45, 46), since the lung and the kidney are not functional in utero. The rapid exchange of heat across the placenta clamps the temperature of the fetus to that of the maternal organism and provides a thermostable environment so that the fetus does not actively regulate temperature independently of the mother (255). Immediately after birth, the maternal supply of
Vance to the support of oxidative metabolism, through provision of oxygen and removal of carbon dioxide. Similarly, the kidneys become functional and participate in excretion of water, urea, and ions. In most species, the newborn is exposed to a cold environment and must maintain body temperature by activating the mechanisms responsible for heat production (shivering and nonshivering thermogenesis)(296). The suckling-weaning transition is also characterized by profound changes of nutrition. Toward the end of the suckling period, the milk intake is gradually replaced by the solid food diet of the adult, of which the composition is higher in carbohydrate and lower in fat. This diet becomes the prevalent diet after weaning. The successful adaptation of neonates to these substrates ceases abruptly, and the newborn has to changes of nutrition and environment requires imporwithstand a brief period of starvation before being fed tant modifications of glucose and fatty acid metabolism at intervals with milk that is a high-fat and low-carbo- that are mainly orchestrated by alterations in hormone
American Physiological Society