The effect of characteristics of proteins fed during gestation and lactation on development of metabolic syndrome in dams and male offspring of Wistar rats.

OBJECTIVE: The objective of the study is to examine the role of characteristics of proteins in maternal and weaning diets on risk of metabolic syndrome in male offspring. METHODS: Pregnant Wistar rats were allocated to two groups (n = 12) and were fed the AIN-93G diets based on either intact protein-based diet (IPD) or mixed amino acid-based diet (AAD) from day 3 of gestation throughout gestation and lactation. Male offspring were weaned to either an IPD or AAD diet for 18 weeks. RESULTS: In dams, AAD group had lower body weight in post-partum period and higher pulse rate compared with IPD group. In pups born to AAD dams, birth weight and body weight were significantly lower, and systolic blood pressure and fasting blood glucose were significantly higher compared with those born to IPD dams. Fat/weight ratio, insulin and homeostasis model assessment of insulin resistance were not influenced by either maternal or weaning diet. CONCLUSIONS: These results indicate that the physico-chemical structure of proteins fed to dams is important in altering risk factors of metabolic syndrome in the offspring, while weaning diets do not seem to play a role. IPD had more favourable effect than AAD. These results may also indicate that dietary recommendations during development must be updated based on physiological properties of dietary proteins that are beyond their nutritional role.

The effect of high multivitamin diet during pregnancy on food intake and glucose metabolism in Wistar rat offspring fed low-vitamin diets post weaning.

Rat offspring born to dams fed a high multivitamin diet (HV) are shown to have increased risks of obesity and metabolic syndrome. We hypothesized that a low-vitamin postweaning diet would enhance these characteristics in offspring born to HV dams. During pregnancy, Wistar rats were fed the AIN-93G diet with or without a 10-fold increase in vitamin content. In Experiment 1, at weaning, males were fed the recommended diet (RV) or a diet with 1/3 the vitamin content (1/3 RV) for 12 weeks. In Experiment 2, males and females were fed the RV diet or 1/6 RV diet for 35 weeks. Body weight was measured on a weekly basis, food intake on a daily basis, and for 1 h after an overnight fast following glucose gavage at 6, 12 and 24 weeks. Blood glucose and insulin responses to an oral glucose load were measured at 30 weeks. Males from HV dams, compared with those from RV dams, gained more weight in Experiment 1 (+7%, P < 0.05) and Experiment 2 (+11%, P < 0.0001), along with higher glucose response (+33%, P < 0.05). The 1/6 RV pup diet led to lower weight gain in males (-16%, P < 0.0001) and females (-13%, P < 0.0005), and lower food intake in males (-9%, P < 0.01) independent of the gestational diet. Females on the 1/6 RV diet and from HV dams had higher 1 h food intake (+36%, P < 0.05) and lower insulin response (-25%, P < 0.05) compared with those from RV dams. Exposure of the offspring to low-vitamin diets did not amplify the expression of the metabolic syndrome observed in those born to dams fed an HV diet.

Multivitamin supplementation during pregnancy alters body weight and macronutrient selection in Wistar rat offspring.

The hypothesis that vitamin content of the diet during gestation alters macronutrient choice, food intake and the expression of serotonin receptors and proopiomelanocortin (POMC) in the hypothalamus of the offspring was investigated. Pregnant Wistar rats (n = 10/group) were fed the AIN-93G diet containing a multivitamin mix at the recommended (RV) content or10-fold higher (high vitamin, HV) content. Male offspring were weaned to a choice of 10% and 60% casein diets. Intake regulation by the serotonergic system was determined by measuring food choice daily for 7 weeks, and following tryptophan (TRP) or mCPP (a serotonin receptor agonist) injections at 4 and 6 weeks post-weaning. mRNA expressions of hypothalamic serotonin receptor and POMC were measured at birth, weaning and sacrifice (7 weeks post-weaning). No differences were found in body weight at birth or weaning. HV offspring had lower food intake for the duration of the study (P < 0.001), and 11% lower body weight (P < 0.05) and 23% lower fat pad mass (P < 0.05) at 7 weeks post-weaning. They selected less protein following 12 h of food deprivation (P < 0.05) and were less responsive to TRP (P = 0.05) and mCPP (P < 0.05) injections at 6 weeks post-weaning. Expressions of mRNA for serotonin receptors 5-HT1A/2A/2C at weaning (P < 0.01) and of POMC at weaning and 7 weeks post-weaning (P < 0.05) were lower. In conclusion, intake of multivitamins above the requirements during pregnancy affected macronutrient choice, food intake and the expression of serotonin receptors and POMC in the hypothalamus.