Hypothalamic peptide and nutrient sensors gene expression in the hypothalamus of neonatal rat.

In the neonate, the main mediator for satiety or hunger is the information of distention or gastric contraction. Food intake controls has two types of a short-term one, based on the level of hydration, and another long-term one, dependent on the gastric stretch. The aim of this study is to evaluate the gene expression of peptides and nutrient sensors in the hypothalamus at 10 and 18 days of postnatal life. Male rats divided into groups: Fasting, Water, Milk, and Gavage.Two age groups had analyzed into 10 and 18 days. Gene expression of hypothalamic peptides, Neuropeptide Y(NPY), Agouti-related peptide(AgRP), proopiomelanocortin(POMC), cocaine-and amphetamine-regulated transcript(CART), and energy sensors mechanistic target of rapamycin(mTOR) and AMP-activated protein kinase(AMPK) in the hypothalamus was seen. During the fasting period, there was an increase in expression of AMPK seen in 10 and 18 days, also mTOR reduction. Expression of NPY, AgRP, and POMC suffered the fasting effect only at 18 days. The effect of gastric distention and energy loads, there was increased expression of AMPK at 10 and 18 days, but expression of mTOR showed only at 18 days. There was increased NPY expression at 18 days, but not at 10 days, while AgRP increased its expression at both ages. At 10 days gene expression of CART increased and POMC as well as 10-18 days. Data demonstrated a simultaneous responsiveness to hypothalamic nutrient sensing also, controlling peptide food consumption even at an early age. The mature standard of control only observed at 18 days of life.

Effects of perinatal protein malnutrition and fenfluramine action on food intake and neuronal activation in the hypothalamus and raphe nuclei of neonate rats.

In neonatal rats, hunger and satiety responses occur particularly via dehydration and gastric distention, respectively. The control of food intake in newborns is yet to be fully consolidated, particularly with respect to the participation of the hypothalamic nuclei and their relationship with the serotonergic pathway. Moreover, it is unclear how the environmental stressors in early life, like undernutrition, interfere in these events. Therefore, this study examined the serotonin-system's impact on food intake in rat neonates at postnatal day (P) 10 and P18 and the manner in which protein undernutrition during pregnancy and lactation interferes in this behavior. To accomplish this, Wistar rats were used, nutritionally manipulated by a diet having two protein levels, (8% and 17%) during pregnancy and lactation, to form the Control (n=10) and Low protein groups (n=10). At 10 and 18 postnatal days pups received an acute dose of fenfluramine (3mg/kg) or saline (0.9% NaCl) and subjected to milk consumption testing and then perfused to obtain the brains for the analysis of cell activation of the immunoreactive c-Fos in the hypothalamic and raphe nuclei. At 10days a reduction in weight gain was observed in both groups. On comparison of the neuronal activation for the paraventricular nucleus, an increased activation in response to fenfluramine was observed. At 18days, the weight gain percentage differed between the groups according to the nutritional manipulation, in which the control animals had no significant change while the undernourished presented increased weight gain with the use of fenfluramine. The marking of c-Fos in response to fenfluramine in the hypothalamic and raphe nuclei revealed, an especially lower activation of the PVN, MnR and DR compared intra-group. However when evaluating the effect of undernutrition, marking activation was observed to increase in all the nuclei analyzed, in the hypothalamus and raphe. Data from this study indicate that the action of serotonin via food intake in the neonates may have been delayed by early protein undernutrition.

Early exposure of dams to a westernized diet has long-term consequences on food intake and physiometabolic homeostasis of the rat offspring.

This study evaluated the long-term effects of a westernized diet during pregnancy and lactation. Female Wistar rats (n = 12) were divided into two groups according to their food intake, namely, control (C) or westernized (W) diet, throughout pregnancy/lactation. On the 21st day, the male pups were weaned on a standard diet as follows: Control diet (CC) (n = 8) and westernized diet in perinatal life followed by control diet post weaning (WC) (n = 8). The levels of fasting (12 h) serum glucose, triglycerides (TG), and total cholesterol and fraction in the pups were determined. During weaning, the WC group showed 14% greater body weight (p < 0.001). In the adulthood, the offspring from dams fed on westernized diet showed hyperphagia, hyperinsulinism, hypertriglyceridemia, higher fat visceral weight, higher very-low-density-lipoprotein cholesterol level, decreased high-density-lipoprotein cholesterol level, and altered glucose tolerance test. In conclusion, maternal western-style diet in early life altered long-term food intake, visceral fat pad, insulin, glucose and lipid serum, and increased risk of metabolic disorders.

Effects of a westernized diet on the reflexes and physical maturation of male rat offspring during the perinatal period.

This study evaluates the effects of a westernized diet during the perinatal period on the maternal performance and growth and development of rat offspring. Female Wistar rats were fed with either a control (C) diet, with casein as the protein source or a westernized (W) diet, during pregnancy and lactation. The pups were divided, eight per group, into the same diet groups as their dams. During lactation, the body weight (day 1, W = 6.85 ± 0.62 g, C = 5.81 ± 0.49, p < 0.05; day 21, W = 55.42 ± 3.78, C = 47.75 ± 3.45, p < 0.001) and somatic growth (body length day 1, W = 53.24 ± 2.16, C = 50.641 ± 1.79, p < 0.05; day 21, W = 124.8, C = 119.903 ± 3.71, p < 0.001) in the male offspring showed significant differences among the groups. The physical appearance and reflex maturation showed differences between day 1 and day 3. With the westernized diet, during the perinatal period, no alterations in maternal weight gain, gestation or performance were observed; however, changes in the coefficients of feed efficiency and energy during lactation were noted. Besides, blood glucose was found to be elevated at the end of lactation (C = 3.67 ± 0.35 mmol/l, W = 5.2 0 ± 0.49 mmol/l). At 21 days, the male pups from the dams on the westernized diet were 15 % heavier, and the maturation of the neural reflexes and physical characteristics were found to occur earlier. Therefore, the consumption of a westernized diet during the perinatal period was independent of maternal energy intake, and influenced the growth and development of offspring.