Skeletal muscle glucose transporter protein responses to antenatal glucocorticoids in the ovine fetus.
Journal - The Journal of endocrinology (England )
We investigated the effects of maternal antenatal dexamethasone (Dex) treatment given as a single course (4 doses) or multiple courses (20 doses) on fetal skeletal muscle glucose transporter (GLUT) protein concentrations at 70% of gestation (106 to 107 days with term being 145 to 150 days) in the ovine fetus. Antenatal corticosteroid administration was associated with a decrease in endogenous fetal plasma cortisol concentrations (P < 0.05), fetal hyperglycemia (P < 0.02) and hyperinsulinemia (P < 0.05). These metabolic/hormonal changes were associated with a decrease in fetal body weight (P < 0.05) in the multiple course Dex group compared with the multiple course placebo group. These perturbations were associated with an increase in fetal skeletal muscle GLUT 1 concentrations that mediate basal glucose transport in the extensor digitorum lateralis and extensor digitorum longus muscles (P < 0.05) 18 h after the last dose of Dex was given in the single course group. However, in the multiple course Dex group, a small increase in GLUT 1 was observed only in the biceps femoris. In contrast, both single and multiple courses of antenatal Dex were associated with an increase in the extensor digitorum lateralis and biceps femoris muscle GLUT 4 (insulin-responsive) concentrations (P < 0.05). We conclude that antenatal corticosteroids perturb fetal glucose/insulin homeostasis, which is associated with increases in fetal skeletal muscle glucose transporters to compensate for and attenuate the associated catabolic fetal state. These changes consist of an increase in proteins that mediate basal glucose transport (GLUT 1) to meet immediate energy requirements of the fetal skeletal muscle with an increase in basal insulin sensitivity (GLUT 4) to compensate for the Dex-induced catabolic state after exposure to multiple courses of Dex.
|ISSN : ||0022-0795|
|Mesh Heading : ||Animals Body Weight Dexamethasone Drug Administration Schedule Female Fetal Diseases Glucocorticoids Glucose Transport Proteins, Facilitative Glucose Transporter Type 1 Glucose Transporter Type 4 Hematocrit Hydrocortisone Hydrogen-Ion Concentration Hyperglycemia Hyperinsulinism Injections, Intramuscular Male Maternal-Fetal Exchange Muscle, Skeletal Myosin Heavy Chains Pregnancy Sheep physiology metabolism analysis analysis blood metabolism metabolism physiology chemistry drug effects analysis|
|Mesh Heading Relevant : ||administration & dosage administration & dosage analysis embryology|