Role of Methyl Group Vitamins in Hypothalamic Development of Food Intake Regulation in Wistar Rats

High multivitamin diets (HV, 10-fold AIN-93G) fed during pregnancy to Wistar rats produce offspring with increased food intake, obesity and characteristics of metabolic syndrome. The hypothesis that methyl group vitamins in HV gestational and pup diets modify expression of the obesogenic phenotypes in the offspring through their effects on hypothalamic feeding pathways regulating food intake was tested by four studies. In studies 1 and 2, dams were fed the AIN-93G diet with recommended vitamin (RV), HV, high methyl vitamins (10-fold folate, vitamin B12 and vitamin B6) (HMethyl) or HV with normal folate (HVNF) and male offspring were weaned to a high fat diet for 8 weeks. In studies 3 and 4, dams were fed RV, HV or high 10-fold folate (HFol), and male offspring were weaned to RV, HV or HFol diets for 29 weeks. The results are as follows: 1. HV and HMethyl diets increased obesogenic phenotypes and altered hypothalamic regulation of food intake and metabolism concurrent with epigenetic effects on gene expression. 2. Removing folate additions to the HV diet showed that folate contributes to the obesogenic phenotype in the offspring and epigenetic alterations in the hypothalamus that favor increased food intake. 3. Matching pup diet vitamin content with that of the HV and HFol diet fed dams prevented their increased food intake, body weight and insulin resistance when weaned to the RV diet. 4. Both HFol gestational and pup diets altered hypothalamic feeding pathways through DNA methylation showing that epigenetic effects of these vitamins occur not only in utero but also postnatally. In conclusion, methyl group vitamins in HV gestational and pup diets modify expression of the obesogenic phenotypes and hypothalamic food intake regulatory systems in the offspring.

Department dc:contributor.department

Nutritional Sciences

Year dc:date.issued

2014

Author dc:creator

• Cho, Clara Euna

Advisor dc:contributor.advisor

• Anderson, Gerald Harvey

• vitamins
• hypothalamus
• obesity
• DNA methylation
• gestation
• post-weaning

Language dc:language.iso

en_ca

Handle dc:identifier.uri

http://hdl.handle.net/1807/72639

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/72639