Introduction: In sheep, modest maternal nutrient restriction over the period of rapid placental growth followed by normal feeding to term results in offspring with a larger placenta and increased expression of the glucocorticoid receptor in a range of tissues. The aim of the present study was to determine whether this subsequently alters the relationship between basal cortisol and blood pressure in later life.
Methods: Fourteen Welsh Mountain ewes were individually housed from 28 days gestation. Six ewes were NR, these consumed 3.5 MJ of metabolisable energy (ME) per day (60% of ME requirements for maintenance and growth of the conceptus) until 80 days gestation, with 8 controls (C) consuming 6.8-7.5 MJ/day. After 80 days gestation, until term (147 days), all animals consumed 6.8-7.5 MJ/day, sufficient to fully meet their ME requirements. At 6 months of age, a carotid artery and jugular vein were surgically catheterised to allow subsequent measurement of basal blood pressure and blood sampling.
Results: There was no difference in basal plasma cortisol between groups (NR 19.7 + 5.1; C 21.7 + 4.2 nmol/l), but lambs born to NR ewes had lower blood pressure for which a positive correlation with plasma cortisol (r2=0.75; P<0.026) was observed. This was not apparent in controls (r2=0.04; NS).
Conclusion: Nutrient restriction between early to mid gestation results in offspring with altered blood pressure responsiveness to cortisol which may contribute to compromised blood pressure sensitivity in later life.
G Gopalakrishnan was supported by a British Heart Foundation studentship.
03 - 04 Dec 2001
Society for Endocrinology