Poster Topical Area: Diet and Cancer
Poster Board Number: 190
Objective: To determine the preventive effect of a nutritional intervention during pregnancy and lactation in obese female mice due to a high-fat diet (HFD).This effect was studied on glucose homeostasis alterations, to evaluate whether it was associated to overactivity of the endocannabinoid system (ECS) in adult offspring liver. This study was supported by previous reports that associates HFD-induced obesity with ECS hyperactivity in tissues involved in energy homeostasis.
Methods and animal treatment: The model considered three experimental groups, 45 days old female mice (C57/BL/6), separated according to diet: Group A: females with control diet before and during pregnancy and lactation; Group B: females with a HFD (fat: 60% Kcal) before and during pregnancy and lactation; Group C: females with a high-fat diet until mating and control diet (fat: 10% Kcal) in pregnancy and lactation. Males used for mating and respective offspring were fed a post-weaning control diet. Offspring (5 of each group) were subjected to a glucose tolerance (GTT) and insulin sensitivity (IST) tests after intraperitoneal injection of glucose and insulin respectively, at 2 and 4 months of life. Mice were sacrificed (120 days old), livers extracted, and immediately frozen in liquid nitrogen. Subsequently, livers were ground frozen and homogenized for determination of CB1 receptor mRNA by real time RT-PCR and protein abundance by Western blot analysis (WB).
Results: There are clear differences by sex in offspring regarding the change of diet in their mothers. In the GGT, male offspring tend to show higher fasting glycemia than females, and during test time (0-120 min), male offspring of the intervened group had fasting glycemia and area under the curve greater than those of the HFD group. Hepatic CB1R mRNA levels were 50% lower in the male offspring of the group of mothers intervened, in comparison with the group of offspring from mothers with HFD, however, these differences do not become statistically significant.
Conclusion: It is possible to observe a normalization effect on the levels of hepatic CB1 receptor mRNA in the male offspring of mothers who were intervened with a control diet. However, these differences are not observed in female offspring, just as it is not possible to observe a preventive effect in the alteration of glucose homeostasis.
INTA, Universidad de Chile
Santiago, Region Metropolitana, Chile