Endocrine Abstracts

Maternal nutrient restriction has been suggested to influence adult offspring HPA axis function. Here, we have studied maternal global nutrient or specific protein restriction and characterised offspring HPA axis response (of plasma cortisol and metabolite excursions) to an insulin tolerance test at 1 year of age. Thirty-nine pregnant sheep were either fed a control diet (replete in energy and protein; n=12) meeting maintenance energy requirements 1.0 M or were fed a diet restricted in energy (0.7 M) during early (0–65 days, LEE; n=7) or late gestation (65–128 days, LEL; n=6) or restricted in protein only (9 vs 18% protein) during (0–60 days, LPE; n=7) or late gestation (61–136 days, LPL; n=6). All lambs were delivered naturally, weaned at 12 weeks and put out on pasture. At 1 year they had an ITT (0.25 IU/kg) and insulin sensitivity, plasma cortisol and lipid metabolites were measured repeatedly over a 2 h period. Baseline plasma cortisol was similar within treatment groups but was significantly affected by study group, being higher overall in those that received energy restriction (energy, 68.1±6.0; protein 55.7±5.8 nmol/l). The cortisol response to ITT was also blunted in the protein restricted animals (Energy 79.6, versus protein, 58 nmol/l per minute, ±S.E.D. 10.3). There was no effect of treatment group on the linear decrease in glucose over the first 15 min after administration of the insulin bolus, but again study appeared to exert the greater effect (Kitt; Energy, −7.84 versus protein, −5.10% decline (mmol/l) min ±1.44 S.E.D.). In summary we have shown little developmental programming of the HPA axis in adult offspring; however we demonstrate that alteration of the protein content of the diet has a greater impact than alteration of the energy content of the diet.