a1 School of Biomedical Sciences, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK
a2 School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough, LE12 5RD, UK
Fetal undernutrition programmes risk of later metabolic disorders. Postnatal factors modify the programmed phenotype. This study aimed to assess the effects of a postnatal high-fat (HF) challenge on body weight gain, adiposity and gene expression following prenatal undernutrition. Pregnant rats were fed either a control diet or a low-protein (LP) diet, targeted at days 0–7 (LPE), days 8–14 (LPM), or days 15–22 (LPL) gestation. At 12 weeks of age offspring were either fed standard laboratory chow diet (4·13 % fat), or a 39·5 % fat diet, for 10 weeks. LP exposure had no effect on weight gain or abdominal fat in males. Females exposed to LP diet in utero exhibited a similar weight gain on HF diet as on the chow diet. Programming of fat deposition was noted in LPE females and males of the LPM and LPL groups (P = 0·019). Hypothalamic expression of galanin mRNA was similar in all groups, but expression of the galanin-2 receptor was modified by LP exposure in female offspring. Hepatic expression of sterol response element binding protein (SREBP-1c) was decreased by LP at both the mRNA (P = 0·008) and protein (P < 0·001) level. HF feeding increased expression of SREBP-1c mRNA three-fold in controls, with little response noted in the LP groups. Interactions of factors such as postnatal diet, age and sex act together with prenatal factors to determine metabolic function and responsiveness at any stage of postnatal life. This study further establishes a role for prenatal nutrition in programming the genes involved in lipid metabolism and appetite regulation.
(Received November 01 2006)
(Revised February 19 2007)
(Accepted February 22 2007)
Abbreviations: gal2r, galanin-2 receptor; LP, low protein; LPE, LP diet targeted at early gestation; LPM, LP diet targeted at mid gestation; LPL, LP diet targeted at late gestation; SREBP, sterol response element binding protein