Immediate Postnatal Overfeeding in Rats Programs Aortic Wall Structure Alterations and Metalloproteinases Dysregulation in Adulthood

Programming of Cardiovascular Dysfunction by Postnatal Overfeeding in Rodents

Nutritional environment in the perinatal period has a great influence on health and diseases in adulthood. In rodents, litter size reduction reproduces the effects of postnatal overnutrition in infants and reveals that postnatal overfeeding (PNOF) not only permanently increases body weight but also affects the cardiovascular function in the short- and long-term. In addition to increased adiposity, the metabolic status of PNOF rodents is altered, with increased plasma insulin and leptin levels, associated with resistance to these hormones, changed profiles and levels of circulating lipids. PNOF animals present elevated arterial blood pressure with altered vascular responsiveness to vasoactive substances. The hearts of overfed rodents exhibit hypertrophy and elevated collagen content. PNOF also induces a disturbance of cardiac mitochondrial respiration and produces an imbalance between oxidants and antioxidants. A modification of the expression of crucial genes and epigenetic alterations is reported in hearts of PNOF animals. In vivo, a decreased ventricular contractile function is observed during adulthood in PNOF hearts. All these alterations ultimately lead to an increased sensitivity to cardiac pathologic challenges such as ischemia-reperfusion injury. Nevertheless, caloric restriction and physical exercise were shown to improve PNOF-induced cardiac dysfunction and metabolic abnormalities, drawing a path to the potential therapeutic correction of early nutritional programming.

Effects of postnatal overfeeding and fish oil diet on energy expenditure in rats

BackgroudEarly life nutrition may have a role in the regulation of metabolism in adulthood. The present study aimed to evaluate the effects of postnatal overfeeding and a postweaning fish oil diet on energy expenditure.MethodsOn postnatal day 3, rat litters were adjusted to a litter size of three (small litters, SLs) or ten (normal litters, NLs). After weaning, SLs were fed the standard diet or a fish oil diet enriched with polyunsaturated fatty acids (SL-FOs) for 10 weeks. The metabolic parameters of rats were monitored using the TSE LabMaster at postnatal week 3 (W₃) and postnatal week 13 (W₁₃).ResultsAt W₃, the O₂ consumption and heat production in SLs were lower than those in NLs, while the respiratory exchange ratio (RER) was higher than NLs. SLs showed obesity, dyslipidemia, and impaired glucose tolerance at W₁₃. The postweaning fish oil diet in SLs not only increased O₂ consumption, CO₂ production, heat production, and reduced the RER but it also reduced weight gain, serum triglycerides, and improved glucose tolerance at W₁₃.ConclusionPostnatal overfeeding can decrease the level of body energy expenditure and induce obesity, but a fish oil diet can increase the energy expenditure and prevent the development of metabolic dysregulation in adults.