Endocrine Abstracts (2001) 2 P77

IMPACT OF MATERNAL NUTRIENT RESTRICTION IN EARLY TO MID GESTATION ON INSULIN-LIKE GROWTH FACTOR-I (IGF-I) RECEPTOR mRNA ABUNDANCE IN THE OVINE PLACENTA

J Bispham, J Dandrea, ME Symonds & T Stephenson


Academic Divsion of Child Health, University of Nottingham, Nottingham, UK.


Introduction: In sheep, modest maternal nutrient restriction over the period of rapid placental growth restricts placentome growth. Maternal plasma IGF-I concentration is unaffected but effects on placental IGF-I receptor mRNA expression are not known.

Methods: Twenty singleton-bearing ewes of similar body weight and parity were entered into the study. Ten ewes consumed 60% of their total energy requirements (i.e. nutrient restricted, NR) from 28 to 80 days gestation and ten consumed 150% of their total energy requirements (i.e. controls, C). All ewes were then fed 150% of their total energy requirements up to 140 days gestation. Placental tissue was sampled after euthanasia from both NR and C ewes at either 80 or 140 days gestation (n= 4-6 per group). Total RNA was extracted. IGF-I receptor mRNA abundance was examined by RT-PCR, using oligonucleotide primers specific to the IGF-I receptor (forward 5'-GCCTCCAACTTTGTCTTTGC-3' and reverse 5'-GCTGAAATACTCCGGGTTCA-3'). Results, in arbitrary units (a.u.; mean plus/minus s.e.m) are a ratio of an 18S rRNA internal control.

Results: At 80 days gestation nutrient restriction resulted in reduced IGF-I receptor mRNA (C: 77.7 plus/minus 9.0; NR: 53.1 plus/minus 2.2 a.u. (P< 0.05))="" when="" placental="" weight="" was="" also="" decreased.="" by="" 140="" days="" gestation="" these="" differences="" had="" been="" negated="" (c:="" 80.6="" plus/minus="" 12.2;="" nr:="" 71.2="" plus/minus="" 3.4="">

Conclusion: Maternal nutrient restriction restricts placental growth and IGF-I receptor mRNA abundance, an effect no longer apparent following nutrient restoration. The extent to which such a reduction in placental IGF-I receptor expression may influence nutrient partitioning to the developing fetus remains to be established.

Article tools

My recent searches

No recent searches.