Effect of omega-3 polyunsaturated fatty acids diets after early over-feeding on expressions of ghrelin in gastric tissue and leptin in serum in adult rats / 中华临床营养杂志

ABSTRACT

Objective To observe ghrelin expression in gastric tissue and serum leptin level of the early over-fed rats given ω-3 polyunsaturated fatty acids (PUFAs) diets after weaning,and explore the effects of early over-feeding and diets intervention on the metabolic syndrome in adult rats.Methods Male Sprague-Dawley rats were divided into normal feeding group (NF group,10 per litter) or over-feeding group (OF group,3 per litter) in postnatal day 3,and then different diets were given after weaning (postnatal day 21).The OF group was separately given conventional diet (OF + Con group),high-fat diet (OF + HF group),or ω-3 PUFAs (OF + ω-3 group) ; while the NF group was separated into NF + Con group and NF + HF group.Body weight and food intake were recorded every week.In week 6 and week 16,glucose tolerance test was perforfmed.Serum leptin,ghrelin,and triglyceride were assayed by enzyme-linked immuno-absorbent assay.Ghrelin mRNA and protein levels in gastric tissue were quantified by real-time PCR and immunohistochemistry.Results At week 16,energy intake,body weight and glucose intolerance in OF + HF group were significantly higher than in NF + HF group (t =-3.453,P =0.014 ; t =-6.406,P =0.000 ; F =16.249,P =0.000),and serum triglycerides,ghrelin mRNA of gastric tissue were significantly higher than those of OF + Con group (t =4.72,P =0.005 ; t =8.486,P =0.000).At week 16,the serum leptin level in OF + Con group was higher than that in NF + Con group (t =-3.274,P =0.031),also higher in OF + HF group than that in OF + Con group (t =3.028,P =0.014).There were no significant differences in serum ghrelin and the area of ghrelin immuno-positive cells in the gastric tissue among groups.The above indicators in OF + ω-3 group were not different from those of NF + Con group.Conclusions Over-feeding during the lactation period may lead to high susceptibility to obesity and disordered glucose and lipid metabolism.It can also increase serum leptin and ghrelin mRNA expression in gastric tissue,aggravate leptin resistance and feeding control disorders.Dietary ω-3 PUFAs offered protection against excessive accumulation of adipose tissue,glucose intolerance,leptin resistance,and maintained normal levels of leptin and ghrelin.