Effect of a high or low ambient perinatal temperature on adult obesity in Osborne-Mendel and S5B/Pl rats

Abstract

Perinatal environment is an important determinant of health status of adults. We tested the hypothesis that perinatal ambient temperature alters sympathetic activity and affects body composition in adult life and that this effect differs between S5B/Pl (S5B) and Osborne-Mendel (OM) strains of rat that were resistant (S5B) or susceptible (OM) to dietary obesity. From 1 wk before birth, rat litters were raised at either 18 or 30°C until 2 mo of age while consuming a chow diet. Rats were then housed at normal housing temperature (22°C) and provided either high-fat or low-fat diet. OM rats initially reared at 18°C gained more weight on both diets than those reared at 30°C. Perinatal temperature had no effect on body weight gain of the S5B rats on either diet. At 12 wk of age, OM and S5B rats reared at 18°C had higher intakes of the high-fat diet than those reared at 30°C but lower β3-adrenergic receptor (β3-AR) and uncoupling protein-1 (UCP1) mRNA levels in brown adipose tissue (BAT). The increase in metabolic rate in response to the β3-agonist CL-316243, was greater in both OM and S5B rats reared at 18°C than in those reared at 30°C. Perinatal temperature differentially affects body weight in OM and S5B rats while having similar effects on food intake, response to a β3-agonist, and BAT β3-AR and UCP-1. The data suggest that OM rats are more susceptible to epigenetic programming than S5B rats.