Endocrinology, Vol 135, 895-900, Copyright © 1994 by Endocrine Society

ARTICLES

Maternal insulin-like growth factor-I infusion alters feto-placental carbohydrate and protein metabolism in pregnant sheep

L Liu, JE Harding, PC Evans and PD Gluckman
Research Center for Developmental Medicine and Biology, University of Auckland, New Zealand.

Insulin-like growth factor-I (IGF-I) in the maternal circulation may have a role in the regulation of placental function and fetal growth, but its mechanisms of action are not known. We studied the effects of maternal IGF-I infusion (30 micrograms/kg.h for 4 h) in eight chronically catheterized pregnant sheep. IGF-I infusion caused an increase in fetal blood glucose concentrations, but no change in placental or fetal glucose uptake. Maternal plasma insulin concentrations fell. Placental lactate production increased by 56%, with most of this lactate taken up by the fetus. Maternal and fetal blood amino nitrogen concentrations fell, but fetal protein oxidation was unchanged. IGF-I infusion did not change feto-placental oxygenation, placental blood flow, or placental transfer by simple or facilitated diffusion. The metabolic effects of maternal IGF-I infusion in part oppose those of fetal IGF-I. We hypothesize that the balance of maternal and fetal IGF-I concentrations contributes to the regulation of substrate distribution between mother, placenta and fetus, and may thus mediate the nutritional regulation of fetal growth.

This article has been cited by other articles:

				A. N. Sferruzzi-Perri, J. A. Owens, P. Standen, R. L. Taylor, G. K. Heinemann, J. S. Robinson, and C. T. Roberts Early treatment of the pregnant guinea pig with IGFs promotes placental transport and nutrient partitioning near term Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E668 - E676. [Abstract] [Full Text] [PDF]

				S Shaikh, F H Bloomfield, M K Bauer, H H Phua, R S Gilmour, and J E Harding Amniotic IGF-I supplementation of growth-restricted fetal sheep alters IGF-I and IGF receptor type 1 mRNA and protein levels in placental and fetal tissues J. Endocrinol., July 1, 2005; 186(1): 145 - 155. [Abstract] [Full Text] [PDF]

				M. Chellakooty, K. Vangsgaard, T. Larsen, T. Scheike, J. Falck-Larsen, J. Legarth, A. M. Andersson, K. M. Main, N. E. Skakkebaek, and A. Juul A Longitudinal Study of Intrauterine Growth and the Placental Growth Hormone (GH)-Insulin-Like Growth Factor I Axis in Maternal Circulation: Association between Placental GH and Fetal Growth J. Clin. Endocrinol. Metab., January 1, 2004; 89(1): 384 - 391. [Abstract] [Full Text] [PDF]

				P. D. Gluckman and C. S. Pinal Regulation of Fetal Growth by the Somatotrophic Axis J. Nutr., May 1, 2003; 133(5): 1741S - 1746. [Abstract] [Full Text] [PDF]

				S. Bhatia, G. H. Faessen, G. Carland, R. L. Balise, S. E. Gargosky, M. Druzin, Y. El-Sayed, D. M. Wilson, and L. C. Giudice A Longitudinal Analysis of Maternal Serum Insulin-Like Growth Factor I (IGF-I) and Total and Nonphosphorylated IGF-Binding Protein-1 in Human Pregnancies Complicated by Intrauterine Growth Restriction J. Clin. Endocrinol. Metab., April 1, 2002; 87(4): 1864 - 1870. [Abstract] [Full Text] [PDF]

				R. P Holmes, J M P Holly, and P. W Soothill Maternal insulin-like growth factor binding protein-1, body mass index, and fetal growth Arch. Dis. Child. Fetal Neonatal Ed., March 1, 2000; 82(2): 113F - 117. [Abstract] [Full Text]

				R.P. Holmes, J.M.P. Holly, and P.W. Soothill Maternal serum insulin-like growth factor binding protein-2 and -3 and fetal growth Hum. Reprod., July 1, 1999; 14(7): 1879 - 1884. [Abstract] [Full Text] [PDF]

				J. E. Harding, P. C. Evans, and P. D. Gluckman Maternal Growth Hormone Treatment Increases Placental Diffusion Capacity But Not Fetal or Placental Growth in Sheep Endocrinology, December 1, 1997; 138(12): 5352 - 5358. [Abstract] [Full Text] [PDF]

				W. W. Hay Jr, C. S. Catz, G. D. Grave, and S. J. Yaffe Workshop Summary: Fetal Growth: Its Regulation and Disorders Pediatrics, April 1, 1997; 99(4): 585 - 591. [Full Text] [PDF]