Presented at the Neonatal Society 2006 Widdowson Meeting.
Marten N1, Sebert S1, Poore KR2, Fowden AL3, Symonds ME1, Mostyn A4
1 Centre for Reproduction and Ear ly Life, Institute of Clinical Research, University Hospital, Nottingham, UK
2 Centre for Developmental Origins of Health and Disease, University of Southampton, Southampton, UK
3 Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
4 School of Nursing, University Hospital, Nottingham, UK
Epidemiological studies demonstrate that low birth weight infants show poor neonatal growth and increased susceptibility to adult metabolic diseases such as obesity and diabetes. Pigs provide an ideal model to examine the influence of birth weight due to the natural variance in piglet weight within a litter. Poore et al have found that adult pigs that had a low bir th weight, experienced rapid catch up growth and had increased fat and impaired glucose intolerance (1,2). PPARα is a nuclear receptor expressed in oxidative tissues involved in stimulating lipid oxidation pathways to prevent storage of fats as well as increasing insulin sensitivity and glucose tolerance. This study examined whether birth weight influences the expression of PPARα in skeletal muscle from pigs at 3 and 12 months of age.
Piglets from 15 litters were weighed at birth and piglets whose birth weight fell within the confidence interval of the mean birth weight were excluded. Piglets were defined as low birth weight (<1.47 kg) or high birth weight (>1.53kg) and maintained as described previously (1). Pigs were euthanased with an overdose of sodium pentobarbitone (200 mg kg-1) at 3 (n=13) and 12 (n=15) months of age to obtain skeletal muscle, all procedures were in accordance with current UK legislation. PPARα was measured using real time PCR. Linear regression and Student’s t test analyses assessed statistical differences.
Although birth weight grouping had no significant effect on PPARα expression at either age, we found positive relationships between birth weight and PPARα expression at 12 months (R2=0.4, P=0.012), and between current weight and PPARα expression at 12 months (R2=0.2, P=0.05) in skeletal muscle. No significant relationships were observed at 3 months of age.
In conclusion, birth weight and, to a lesser extent, current weight, are positively related to PPARα expression in skeletal muscle in the adult pig. This may promote lipid accumulation and insulin insensitivity in low birth weight piglets in later life.
Acknowledgements: NM was supported by a Wellcome Trust Vacation Scholarship.
References
1. Poore, K. R.; Fowden, A. L. Diabetologia 2002, 45, 1247-1254.
2. Poore, K. R.; Fowden, A. L. Journal of Physiology 2004, 558, 295-304.