Endocrine Abstracts

Introduction: Mice in which the prolactin receptor (PRLR) gene is knocked out have reduced adipose tissue in later life. Abundance of the PRLR is greatest in adipose tissue at birth and is reduced following placental restriction. The present study investigated the impact of maternal nutrient restriction over the final two months of gestation on PRLR abundance in developing lambs.

Methods: Eighteen multiparous twin bearing ewes were entered into the study, 9 were fed to fully meet their total metabolisable energy requirements and 9 were nutrient restricted (NR) and fed 50% of this amount from 8 weeks before term. At one day or one month after birth one twin from each ewe was randomly selected and humanely euthanased to enable adipose tissue sampling. The long and short forms of PRLR were then determined by immunoblotting and results expressed as a percentage of a reference (% ref) sample included on all gels. Results were analysed by analysis of variance and are presented as means with their standard errors.

Results: There was no difference in body weights between groups but lambs born to NR ewes laid down less adipose tissue over the first month of life. This was associated with a significant decrease in the abundance of the long (Control 143plus/minus34, NR 53plus/minus11 % ref (P<0.05)) but not short form of PRLR at birth.

Conclusion: A reduction in long, but not short form, of PRLR at birth is accompanied by reduced adipose tissue deposition in later life. This suggests a novel route by which excess fat deposition may be prevented during postnatal life.

N Korur supported by a Wellcome Trust vacation scholarship and S Pearce was supported by a BBSRC Postgraduate studentship