Hepatic glucose regulation and metabolism in adult sheep: effects of prenatal betamethasone

• Published in: American journal of physiology: endocrinology and metabolism 2005-10, Vol.289 (4), p.E721-E728
• Main Authors: Sloboda, Deborah M, Moss, Timothy J. M, Li, Shaofu, Doherty, Dorota A, Nitsos, Ilias, Challis, John R. G, Newnham, John P
• Format: Article
• Language: English
• Subjects: Animals; Betamethasone - administration & dosage; Blood Glucose - metabolism; Female; Glucocorticoids - administration & dosage; Injections, Intramuscular; Insulin - blood; Liver - drug effects; Liver - embryology; Liver - metabolism; Maternal-Fetal Exchange; Pregnancy; Prenatal Exposure Delayed Effects; Sheep
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.00040.2005

1 School of Women's and Infants' Health, The University of Western Australia, and 2 Women and Infants Research Foundation, Perth, Australia; and 3 Canadian Institutes of Health Research Group in Fetal and Neonatal Health and Development, Departments of Physiology and Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada Submitted 31 January 2005 ; accepted in final form 27 May 2005 Fetal exposure to synthetic glucocorticoids in sheep results in increased fetal hepatic 11 -hydroxysteroid dehydrogenase type 1 (11 -HSD1) and corticosteroid-binding globulin (CBG) protein levels and insulin resistance in postnatal life. The aim was to determine whether these changes persisted to adulthood and whether alterations in mediators of hepatic glucocorticoid and glucose regulation contributed to changes in metabolism. Pregnant ewes or their fetuses received either repeated intramuscular saline (MS, FS) or betamethasone injections (0.5 mg/kg; M4, F4) at 104, 111, 118, and 124 days of gestation (dG), or a single betamethasone injection at 104 dG followed by saline at 111, 118, and 124 dG (M1, F1). Offspring were catheterized at 2 and 3 yr of age and given an intravenous glucose challenge (0.5 mg/kg). Hepatic tissue was collected at 3.5 yr. At 2 yr of age, basal plasma insulin was elevated in M4 offspring and at 3 yr of age was elevated in F4 offspring. Basal insulin-to-glucose ratio was significantly elevated in M4 offspring at 2 yr of age and elevated in M1, M4, and F4 offspring at 3 yr of age. All betamethasone treatments resulted in significant increases in hepatic glucose-6-phosphatase (G-6-Pase) activity. Hepatic glucocorticoid receptor protein levels were not altered in M1 and M4 offspring but were increased in F1 and F4 offspring. Hepatic CBG protein levels were lower in F4 but not F1 offspring and were unchanged from control in M1 and M4 offspring. Prenatal betamethasone exposure results in elevated hepatic G-6-Pase activity in adulthood and may contribute to long-term changes in metabolism. glucocorticoids; metabolism; programming; liver; glucose-6-phosphatase Address for reprint requests and other correspondence: D. M. Sloboda, School of Women's and Infants' Health, Univ. of Western Australia and Women and Infants Research Foundation, King Edward Memorial Hospital, Bagot Rd. Subiaco, Western Australia 6008 (e-mail: dsloboda{at}obsgyn.uwa.edu.au )