Hyperphagia and hyperleptinemia induced by low-protein, high-carbohydrate diet is reversed at a later stage of development in rats.

This study investigated whether increased food intake after 15 days of low-protein, high-carbohydrate (LPHC) and its normalization in the later period of development change the content of key proteins related to leptin or adiponectin signaling in the hypothalamus. Male rats were divided into five groups: Control groups received a control diet (17% protein, 63% carbohydrate) for 15 (C15) or 45 (C45) days; LPHC groups received an LPHC diet (6% protein, 74% carbohydrate) for 15 (LPHC15) or 45 (LPHC45) days; and Reverse group (R): received LPHC diet for 15 days followed by control diet for another 30 days. The LPHC15 group showed increased adiposity index, leptin level, and adiponectin level, as well as decreased the leptin receptor (ObRb) and pro-opiomelanocortin (POMC) content in the hypothalamus compared with the C15 group. LPHC diet for 45 days or diet reversion (R group) rescued these alterations, except the adiponectin level in LPHC45 rats, which was higher. In summary, LPHC diet reduced hypothalamic leptin action by diminishing ObRb and POMC levels, leading to hyperphagia and adiposity body. Medium-term administration of LPHC diet or reverting to control diet restored the levels of these proteins, thereby improving body lipid mass rearrangement in adulthood.

Protein malnutrition early in life increased apoptosis but did not alter the ß-cell mass during gestation.

We evaluated whether early-life protein restriction alters structural parameters that affect ß-cell mass on the 15th day and 20th day of gestation in control pregnant (CP), control non-pregnant (CNP), low-protein pregnant (LPP) and low-protein non-pregnant (LPNP) rats from the fetal to the adult life stage as well as in protein-restricted rats that recovered after weaning (recovered pregnant (RP) and recovered non-pregnant). On the 15th day of gestation, the CNP group had a higher proportion of smaller islets, whereas the CP group exhibited a higher proportion of islets larger than the median. The ß-cell mass was lower in the low-protein group than that in the recovered and control groups. Gestation increased the ß-cell mass, ß-cell proliferation frequency and neogenesis frequency independently of the nutritional status. The apoptosis frequency was increased in the recovered groups compared with that in the other groups. On the 20th day of gestation, a higher proportion of islets smaller than the median was observed in the non-pregnant groups, whereas a higher proportion of islets larger than the median was observed in the RP, LPP and CP groups. ß-Cell mass was lower in the low-protein group than that in the recovered and control groups, regardless of the physiological status. The ß-cell proliferation frequency was lower, whereas the apoptosis rate was higher in recovered rats compared with those in the low-protein and control rats. Thus, protein malnutrition early in life did not alter the mass of ß-cells, especially in the first two-thirds of gestation, despite the increase in apoptosis.

The Role of Fatty Acids in Ceramide Pathways and Their Influence on Hypothalamic Regulation of Energy Balance: A Systematic Review.

Obesity is a global health issue for which no major effective treatments have been well established. High-fat diet consumption is closely related to the development of obesity because it negatively modulates the hypothalamic control of food intake due to metaflammation and lipotoxicity. The use of animal models, such as rodents, in conjunction with in vitro models of hypothalamic cells, can enhance the understanding of hypothalamic functions related to the control of energy balance, thereby providing knowledge about the impact of diet on the hypothalamus, in addition to targets for the development of new drugs that can be used in humans to decrease body weight. Recently, sphingolipids were described as having a lipotoxic effect in peripheral tissues and the central nervous system. Specifically, lipid overload, mainly from long-chain saturated fatty acids, such as palmitate, leads to excessive ceramide levels that can be sensed by the hypothalamus, triggering the dysregulation of energy balance control. However, no systematic review has been undertaken regarding studies of sphingolipids, particularly ceramide and sphingosine-1-phosphate (S1P), the hypothalamus, and obesity. This review confirms that ceramides are associated with hypothalamic dysfunction in response to metaflammation, endoplasmic reticulum (ER) stress, and lipotoxicity, leading to insulin/leptin resistance. However, in contrast to ceramide, S1P appears to be a central satiety factor in the hypothalamus. Thus, our work describes current evidence related to sphingolipids and their role in hypothalamic energy balance control. Hypothetically, the manipulation of sphingolipid levels could be useful in enabling clinicians to treat obesity, particularly by decreasing ceramide levels and the inflammation/endoplasmic reticulum stress induced in response to overfeeding with saturated fatty acids.

Early weaning induces short- and long-term effects on pancreatic islets in Wistar rats of both sexes.

KEY POINTS: The World Health Organization recommends exclusive breastfeeding until 6 months of age as an important strategy to reduce child morbidity and mortality. Studies have associated early weaning with the development of obesity and type 2 diabetes in adulthood. In our model, we demonstrated that early weaning leads to increased insulin secretion in adolescent males and reduced insulin secretion in adult offspring. Early weaned males exhibit insulin resistance in skeletal muscle. Early weaning did not change insulin signalling in the muscle of female offspring. Taking into account that insulin resistance is one of the primary factors for the development of type 2 diabetes mellitus, this work demonstrates the importance of breastfeeding in the fight against this disease. ABSTRACT: Early weaning (EW) leads to short- and long-term obesity and diabetes. This phenotype is also observed in experimental models, in which early-weaned males exhibit abnormal insulinaemia in adulthood. However, studies regarding the effect of EW on pancreatic islets are rare. We investigated the mechanisms by which glycaemic homeostasis is altered in EW models through evaluations of insulin secretion and its signalling pathway in offspring. Lactating Wistar rats and their pups were divided into the following groups: non-pharmacological EW (NPEW): mothers were wrapped with an adhesive bandage on the last 3 days of lactation; pharmacological EW (PEW): mothers received bromocriptine to inhibit prolactin (1 mg/kg body mass/day) on the last 3 days of lactation; and control (C): pups underwent standard weaning at PN21. Offspring of both sexes were euthanized at PN45 and PN180. At PN45, EW males showed higher insulin secretion (vs. C). At PN170, PEW males exhibited hyperglycaemia in an oral glucose tolerance test (vs. C and NPEW). At PN180, EW male offspring were heavier; however, both sexes showed higher visceral fat. Insulin secretion was lower in EW offspring of both sexes. Males from both EW groups had lower glucokinase in islets, but unexpectedly, PEW males showed higher GLUT2, than did C. EW males exhibited lower insulin signalling in muscle. EW females exhibited no changes in these parameters compared with C. We demonstrated distinct alterations in the insulin secretion of EW rats at different ages. Despite the sex dimorphism in insulin secretion in adolescence, both sexes showed impaired insulin secretion in adulthood due to EW.

Body Adiposity and Endocrine Profile of Female Wistar Rats of Distinct Ages that were Early Weaned.

Early weaning (EW) is a risk factor for metabolic syndrome. Male rats that were precociously weaned present neonatal malnutrition and, in adulthood, developed overweight, accumulation of body fat, dyslipidemia, changes in glycemic homeostasis, hyperleptinemia, and increase of vitamin D. As metabolic profile of early-weaned females is not known, we investigated the endocrine-metabolic parameters in adolescence and adult female rats of 2 different EW models. Wistar lactating rats and pups from both sexes were separated into 3 groups: non-pharmacological EW (NPEW), dams were involved with a bandage interrupting suckling in the last 3 days of lactation; pharmacological EW (PEW), dams were bromocriptine-treated (0.5 mg/twice a day via intraperitoneal injection) for 3 days before weaning; and control, dams whose pups ate milk throughout lactation. At 21 days-old, NPEW and PEW females had lower body weight. At 180 days-old, NPEW and PEW females showed higher feed efficiency, weight gain, body fat percentage, and greater accumulation of gonadal and retroperitoneal fat depots associated with adipocyte hypertrophy. NPEW females also showed hyperphagia. Only NPEW females presented hyperleptinemia. Plasma thyroid hormones and vitamin D were unchanged among EW females. Regarding sex hormones, at 45 days-old, no change was found in EW females, while at 180 days-old, PEW females had hypoestrogenemia. EW increases the risk for obesity in female rats in adulthood, as already demonstrated for males, although through distinct mechanisms involving some hormones.

Senescence and the Impact on Biodistribution of Different Nanosystems: the Discrepancy on Tissue Deposition of Graphene Quantum Dots, Polycaprolactone Nanoparticle and Magnetic Mesoporous Silica Nanoparticles in Young and Elder Animals.

PURPOSES: Senescence is an inevitable and irreversible process, which may lead to loss in muscle and bone density, decline in brain volume and loss in renal clearance. Although aging is a well-known process, few studies on the consumption of nanodrugs by elderly people were performed. METHODS: We evaluated three different nanosystems: i) carbon based nanosystem (Graphene Quantum Dots, GQD), ii) polymeric nanoparticles and mesoporous silica (magnetic core mesoporous silica, MMSN). In previous studies, our group has already characterized GQD and MMSN nanoparticles by dynamic light scattering analysis, atomic force microscopy, transmission electron microscopy, X-ray diffraction, Raman analysis, fluorescence and absorbance. The polymeric nanoparticle has been characterized by AFM and DLS. All the nanosystems were radiolabeled with 99 m-Tc by. The in vivo biodistribution/tissue deposition analysis evaluation was done using elder (PN270) and young (PN90) mice injected with radioactive nanosystems. RESULTS: The nanosystems used in this study were well-formed as the radiolabeling processes were stable. Biodistribution analysis showed that there is a decrease in the uptake of the nanoparticles in elder mice when compared to young mice, showing that is necessary to increase the initial dose in elder people to achieve the same concentration when compared to young animals. CONCLUSION: The discrepancy on tissue distribution of nanosystems between young and elder individuals must be monitored, as the therapeutic effect will be different in the groups. Noteworthy, this data is an alarm that some specific conditions must be evaluated before commercialization of nano-drugs. Graphical Abstract Changes between younger and elderly individuals are undoubtedly, especially in drug tissue deposition, biodistribution and pharmacokinetics. The same thought should be applied to nanoparticles. A comprehensive analysis on how age discrepancy change the biological behavior of nanoparticles has been performed.

Maternal soy protein isolate diet during lactation programmes to higher metabolic risk in adult male offspring.

Soy consumption and its components, including its protein, are related to the beneficial effects of the lipid profile, decreased insulin resistance and glycaemia. However, the safety of the consumption of products containing phytoestrogens in critical stages of development has been questioned, since they may be associated with endocrine-metabolic dysfunctions in adult life. The purpose is to evaluate the effects of maternal dietary soy protein isolate (SPI) during lactation on the breast milk composition, body composition, lipid and glycaemic profiles, and thyroid hormones of dams and offspring at weaning (21 days) and in adulthood (150 days). Lactating rats were divided into casein control (C) and SPI diet groups. At 150 days, the SPI offspring presented lower body protein mass and total mineral content, higher serum FT4, insulin, TC and TG. Maternal consumption of SPI during lactation programmes the progeny to higher metabolic risk profile.

A low-protein, high carbohydrate diet induces increase in serum adiponectin and preserves glucose homeostasis in rats.

The aim of this study was investigate the effects of a low-protein, high-carbohydrate (LPHC) diet introduced to rats soon after weaning. The animals were distributed in the following groups: LPHC45: fed an LPHC diet (6%-protein, 74%-carbohydrate) for 45 days; C45: fed a control (C) diet (17%-protein, 63%-carbohydrate) for 45 days; R (Reverse): fed with LPHC for 15 days followed by C diet for 30 days. The LPHC45 group showed alterations in the energetic balance with an increase in brown adipose tissue, and in glucose tolerance, and lower final body weight, muscle mass and total protein in blood when compared with C45 group. The HOMA-IR index was similar between LPHC45 and C45 groups, but this parameter was lower in LPHC45 compared with R groups. Serum adiponectin was higher in LPHC45 group than C45 and R groups. The R group presented higher fed insulin than C45 and LPHC45 and higher T4 compared with C45 group. Total cholesterol in R group was higher when compared with LPHC45 group. Thus, the data show that the change of the diet LPHC for a balanced diet led to different metabolic evolution and suggest that the different response can be due to different levels of adiponectin.

Short-Term and Long-Term Effects of Bisphenol A (BPA) Exposure During Breastfeeding on the Biochemical and Endocrine Profiles in Rats.

Neonates can be exposed to bisphenol A (BPA) through placenta and milk, and BPA is associated with disorders such as precocious puberty and obesity. We evaluated the effects of BPA exposure during breastfeeding on the biochemical and endocrine profiles in young and adult rat progeny. From postnatal day (PND) 3 to 15 dams were divided into low-dose BPA treatment [50 µg/kg/day s.c. (BPA-LD)], high-dose BPA treatment [5 mg/kg/day s.c. (BPA-HD)], and Control (vehicle) groups. Milk was collected at PND15 and 21, which represents the end of exposure and 6 days after withdrawal, respectively. Dams were euthanized at weaning. Offspring of both genders were euthanized at PND15, 21, and 180. Milk estradiol levels were lower in the BPA-HD group than in the control group at PND 15; however, they were higher at PND21. Female rats whose mothers were BPA-exposed showed more significant differences from those in the control group, including better glycemic control and lipid profiles and higher food intake without higher adiposity, in adulthood than in the weaning period, when they presented with higher adiposity and hyperestrogenism. Conversely, male rats showed more abnormalities after BPA exposure compared to control rats, including insulin, leptin, testosterone, and thyroid hormone changes, when young but exhibited fewer alterations in adulthood, with increase only in LDLc in the BPA-HD rats. Taken together, the present findings suggest that exposure to BPA exclusively through milk affects adiposity, metabolism, and/or hormones of offspring in the short and long term, possibly compromising normal development in both sexes.

Cranberry (Vaccinium macrocarpon) extract treatment improves triglyceridemia, liver cholesterol, liver steatosis, oxidative damage and corticosteronemia in rats rendered obese by high fat diet.

PURPOSE: Obese individuals have higher production of reactive oxygen species, which leads to oxidative damage. We hypothesize that cranberry extract (CE) can improve this dysfunction in HFD-induced obesity in rats since it has an important antioxidant activity. Here, we evaluated the effects of CE in food intake, adiposity, biochemical and hormonal parameters, lipogenic and adipogenic factors, hepatic morphology and oxidative balance in a HFD model. METHODS: At postnatal day 120 (PN120), male Wistar rats were assigned into two groups: (1) SD (n = 36) fed with a standard diet and (2) HFD (n = 36), fed with a diet containing 44.5% (35.2% from lard) energy from fat. At PN150, 12 animals from SD and HFD groups were killed while the others were subdivided into four groups (n = 12/group): animals that received 200 mg/kg cranberry extract (SD CE, HFD CE) gavage/daily/30 days or water (SD, HFD). At PN180, animals were killed. RESULTS: HFD group showed higher body mass and visceral fat, hypercorticosteronemia, higher liver glucocorticoid sensitivity, cholesterol and triglyceride contents and microsteatosis. Also, HFD group had higher lipid peroxidation (plasma and tissues) and higher protein carbonylation (liver and adipose tissue) compared to SD group. HFD CE group showed lower body mass gain, hypotrygliceridemia, hypocorticosteronemia, and lower hepatic cholesterol and fatty acid synthase contents. HFD CE group displayed lower lipid peroxidation, protein carbonylation (liver and adipose tissue) and accumulation of liver fat compared to HFD group. CONCLUSION: Although adiposity was not completely reversed, cranberry extract improved the metabolic profile and reduced oxidative damage and steatosis in HFD-fed rats, which suggests that it can help manage obesity-related disorders.

Leptin blocks the inhibitory effect of vitamin D on adipogenesis and cell proliferation in 3T3-L1 adipocytes.

Recently, we demonstrated high serum leptin and 25(OH)D (calcidiol) in obese animals, with high C/EBPß and PPARγ expression in adipose tissue. Since the role of vitamin D in adipogenesis remains controversial and hyperleptinemia is found in obesity, we asked if leptin could interfere in vitamin D action on adipocytes. Here, we studied the direct effect of these two hormones upon 3T3L1 preadipocytes incubated with or without 1,25(OH)2D (100 nM, 24 h) and with leptin (10-7 M, 4 h later). RT-PCR (VDR and Cyp27b1/1α-hydroxylase), western blotting (VDR, Cyp27b1/1α-hydroxylase, ObR-b, C/EBPß, PPARγ and Bax content), a cell proliferation assay and an Annexin V-FITC binding assay were performed. Incubation with 1,25(OH)2D decreased Cyp27b1/1α-hydroxylase and VDR. Co-incubation of 1,25(OH)2D and leptin did not change Cyp27b1/1α-hydroxylase and had no additive effect upon the decreased VDR mRNA. Incubation with 1,25(OH)2D decreased C/EBPß and PPARγ. In the cell proliferation assay, 1,25(OH)2D decreased the number of 3T3L1 cells. No changes in OBR-b or apoptotic parameters (Bax and annexin-V) were observed. The 1,25(OH)2D decreased pro-adipogenic factors and proliferation of adipocytes. However, since it inhibits the conversion of 25(OH)D to 1,25(OH)2D and VDR mRNA long-term, it could decrease the vitamin D response in adipocytes, leading to greater adipogenesis. The co-incubation of both hormones, simulating what occurs in obesity, even neutralizing the effect on Cyp27b1/1α-hydroxylase, did not change the vitamin D sensitivity but decreased SOCS-3 and pSTAT-3. Thus, an excess of vitamin D and hyperleptinemia could decrease vitamin D sensitivity in adipocytes, contributing to increased adipogenesis.

Cigarette Smoke During Breastfeeding in Rats Changes Glucocorticoid and Vitamin D Status in Obese Adult Offspring.

Maternal smoking increases obesogenesis in the progeny. Obesity is associated with several hormonal dysfunctions. In a rat model of postnatal tobacco smoke exposure, we previously reported increased central fat depot and disruption of some hormonal systems in the adult offspring. As both glucocorticoids and vitamin D alter lipogenesis and adipogenesis, here we evaluated the metabolism of these two hormones in visceral adipose tissue (VAT) and liver by Western blotting, and possible associations with lipogenesis biomarkers in adult rats that were exposed to tobacco smoke during their suckling period. At postnatal day (PN) 3, dams and offspring of both sexes were exposed (S group) or not (C group) to tobacco smoke, 4 × 1 h/day. At PN180, corticosteronemia was lower in S male and higher in S female offspring, without alterations in peripheral glucocorticoid metabolism and receptor. Adrenal ACTH receptor (MC2R) was higher in both sexes of S group. Despite unchanged serum vitamin D, liver 25-hydroxylase was higher in both sexes of S group. Male S offspring had higher 1α-hydroxylase, acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) in VAT. Both sexes showed increased ACC protein content and reduced sirtuin mRNA in liver. Male S offspring had lower liver peroxisome proliferator-activated receptor-α. Tobacco exposure during lactation induced abdominal obesity in both sexes via distinct mechanisms. Males and females seem to develop HPA-axis dysfunction instead of changes in glucocorticoid metabolism and action. Lipogenesis in VAT and liver, as well as vitamin D status, are more influenced by postnatal smoke exposure in male than in female adult rat offspring.

Bromocriptine treatment at the end of lactation prevents hyperphagia, higher visceral fat and liver triglycerides in early-weaned rats at adulthood.

Non-pharmacological early weaning (NPEW) leads offspring to obesity, higher liver oxidative stress and microsteatosis in adulthood. Pharmacological EW (PEW) by maternal treatment with bromocriptine (BRO) causes obesity in the adult progeny but precludes hepatic injury. To test the hypothesis that BRO prevents the deleterious changes of NPEW, we injected BRO into the pups from the NPEW model in late lactation. Lactating rats were divided into two groups: dams with an adhesive bandage around the body to prevent breastfeeding on the last 3 days of lactation and dams whose pups had free suckling (C). Offspring from both groups were subdivided into two groups: pups treated with BRO (intraperitoneal (i.p.) 4 mg/kg per day) on the last 3 days of lactation (NPEW/BRO and C/BRO) or pups treated with the vehicle (NPEW and C). At PN120, offspring were challenged with a high fat diet (HFD), and food intake was recorded after 30 minutes and 12 hours. Rats were killed at PN120 and PN200. At PN120, adipocyte size was greater in the NPEW group but was normal in the NPEW/BRO group. At PN200, the NPEW group presented hyperphagia, higher adiposity, adipocyte hypertrophy, hyperleptinaemia, glucose intolerance and increased hepatic triglycerides. These parameters were normalized in the NPEW/BRO group. In the feeding test, BRO groups showed lower HFD intake at 30 minutes than did their controls; however, at 12 hours, the NPEW group ate more HFD. The treatment with BRO can preclude some deleterious effects of the NPEW model, which prevented the development of overweight and its comorbidities.

Protein-energy malnutrition at mid-adulthood does not imprint long-term metabolic consequences in male rats.

PURPOSE: The long-term effects of the development of chronic metabolic diseases such as type 2 diabetes and obesity have been associated with nutritional insults in critical life stages. In this study, we evaluated the effect of a low-protein diet on metabolism in mid-adulthood male rats. METHODS: At 90 days of age, Wistar male rats were fed a low-protein diet (4.0 %, LP group) for 30 days, whereas control rats were fed a normal-protein diet (20.5 %, NP group) throughout their lifetimes. To allow for dietary rehabilitation, from 120 to 180 days of age, the LP rats were fed a normal-protein diet. Then, we measured body composition, fat stores, glucose-insulin homeostasis and pancreatic islet function. RESULTS: At 120 days of age, just after low-protein diet treatment, the LP rats displayed a strong lean phenotype, hypoinsulinemia, as assessed under fasting and glucose tolerance test conditions, as well as weak pancreatic islet insulinotropic response to glucose and acetylcholine (p < 0.01). At 180 days of age, after poor-protein diet rehabilitation, the LP rats displayed a slight lean phenotype (p < 0.05), which was associated with a high body weight gain (p < 0.001). Additionally, fat pad accumulation, glycemia and insulinemia, as well as the pancreatic islet insulinotropic response, were not significantly different between the LP and NP rats (p > 0.05). CONCLUSIONS: Taken together, the present data suggest that the effects of dietary restriction as a stressor in adulthood are reversible with dietary rehabilitation, indicating that adulthood is not a sensitive or critical time window for metabolic programming.

Maternal flaxseed diet during lactation changes adrenal function in adult male rat offspring.

Flaxseed (Linum usitatissimum L.) has been a focus of interest in the field of functional foods because of its potential health benefits. However, we hypothesised that maternal flaxseed intake during lactation could induce several metabolic dysfunctions in adult offspring. In the present study, we aimed to characterise the adrenal function of adult offspring whose dams were supplemented with whole flaxseed during lactation. At birth, lactating Wistar rats were divided into two groups: rats from dams fed the flaxseed diet (FLAX) with 25% of flaxseed and controls dams. Pups received standard diet after weaning and male offspring were killed at age 180 days old to collect blood and tissues. We evaluated body weight and food intake during development, corticosteronaemia, adrenal catecholamine content, hepatic cholesterol, TAG and glycogen contents, and the protein expression of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), 11-ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) and adrenaline ß2 receptor at postnatal day 180 (PN180). After weaning, pups from the FLAX group had a higher body weight (+10 %) and food intake (+10%). At PN180, the FLAX offspring exhibited higher serum corticosterone (+48%) and lower adrenal catecholamine ( - 23%) contents, lower glycogen ( - 30%), higher cholesterol (4-fold increase) and TAG (3-fold-increase) contents in the liver, and higher 11ß-HSD1 (+62%) protein expression. Although the protein expression of hypothalamic CRH was unaffected, the FLAX offspring had lower protein expression of pituitary ACTH ( - 34%). Therefore, induction of hypercorticosteronaemia by dietary flaxseed during lactation may be due to an increased hepatic activation of 11ß-HSD1 and suppression of ACTH. The changes in the liver fat content of the FLAX group are suggestive of steatosis, in which hypercorticosteronaemia may play an important role. Thus, it is recommended that lactating women restrict the intake of flaxseed during lactation.

Early weaning by maternal prolactin inhibition leads to higher neuropeptide Y and astrogliosis in the hypothalamus of the adult rat offspring.

The suppression of prolactin production with bromocriptine (BRO) in the last 3 d of lactation reduces milk yield (early weaning) and increases the transfer of leptin through the milk, causing hyperleptinaemia in pups. In adulthood, several changes occur in the offspring as a result of metabolic programming, including overweight, higher visceral fat mass, hypothyroidism, hyperglycaemia, insulin resistance, hyperleptinaemia and central leptin resistance. In the present study, we investigated whether overweight rats programmed by early weaning with maternal BRO treatment have hypothalamic alterations in adulthood. We analysed the expression of neuropeptide Y (NPY), cocaine- and amphetamine-regulated transcript (CART), pro-opiomelanocortin (POMC) and α-melanocyte-stimulating hormone (α-MSH) by immunohistochemistry in the following hypothalamic nuclei: medial and lateral arcuate nucleus (ARC); paraventricular nucleus (PVN); lateral hypothalamus (LH). Additionally, we sought to determine whether these programmed rats exhibited hypothalamic inflammation as indicated by astrogliosis. NPY immunostaining showed a denser NPY-positive fibre network in the ARC and PVN (+82% in both nuclei) of BRO offspring. Regarding the anorexigenic neuropeptides, no difference was found for CART, POMC and α-MSH. The number of astrocytes was higher in all the nuclei of BRO rats. The fibre density of glial fibrillary acidic protein was also increased in both medial and lateral ARC (6·06-fold increase and 9·13-fold increase, respectively), PVN (5·75-fold increase) and LH (2·68-fold increase) of BRO rats. We suggest that early weaning has a long-term effect on the expression of NPY as a consequence of developmental plasticity, and the presence of astrogliosis indicates hypothalamic inflammation that is closely related to overweight and hyperleptinaemia observed in our model.

Ilex paraguariensis (yerba mate) improves endocrine and metabolic disorders in obese rats primed by early weaning.

PURPOSE: We showed that early weaned rats developed obesity, hyperleptinemia, leptin and insulin resistance at adulthood. Here, we studied the potential beneficial effects of Ilex paraguariensis aqueous solution upon body composition, glycemia, lipid and hormonal profiles, leptin signaling and NPY content. METHODS: To induce early weaning, lactating rats' teats were blocked with a bandage to interrupt lactation during the last 3 days (EW group), while control offspring had free access to milk throughout lactation (C group). In postnatal day (PN) 150, EW offspring were subdivided into: EW and EW+ mate groups treated, respectively, with water or yerba mate aqueous solution (1 g/kg BW/day, gavage) during 30 days. C offspring received water for gavage. In PN180, offspring were killed. RESULTS: EW+ mate group presented lower body weight (-10 %), adipose mass (retroperitoneal:-40 % and epididymal:-44 %), total body fat (-43 %), subcutaneous fat (-46 %), visceral adipocyte area (-21 %), triglyceridemia (-31 %) and hypothalamic NPY content (-37 %) compared to EW group. However, hyperglycemia and lower HDL-c levels observed in EW group were not reverted with mate treatment. Although the hyperleptinemia, lower hypothalamic JAK2 and pSTAT3 content of EW group were not corrected by mate treatment, the hyperphagia and higher hypothalamic SOCS-3 content were normalized in EW+ mate group, indicating that the central leptin resistance could be restored. CONCLUSION: Thus, the therapy with yerba mate solution was capable to reverse abdominal obesity, leptin resistance and hypertriglyceridemia, suggesting an important role of this bioactive component in the management of obesity in this programming model.

Butter naturally enriched in cis-9, trans-11 CLA prevents hyperinsulinemia and increases both serum HDL cholesterol and triacylglycerol levels in rats.

BACKGROUND: Evidence from in vitro and animal studies indicates that conjugated linoleic acid (CLA) possesses anti-diabetic properties, which appear to be attributed to cis-9, trans-11 CLA, the major CLA isomer in ruminant fat. However, there is a shortage of studies addressing CLA from natural source. The present study aimed to evaluate the effects of butter naturally enriched in cis-9, trans-11 CLA on parameters related to glucose tolerance, insulin sensitivity and dyslipidemia in rats. METHODS: Forty male Wistar rats were randomly assigned to the following dietary treatments (n=10/group), for 60 days: 1) Normal fat-Soybean oil (NF-So): diet containing 4.0% soybean oil (SO); 2) High Fat-Control Butter (HF-Cb): diet containing 21.7% control butter and 2.3% SO; 3) High Fat-CLA enriched Butter (HF-CLAb): diet containing 21.7% cis-9, trans-11 CLA-enriched butter and 2.3% SO; and 4) High fat-Soybean oil (HF-So): diet containing 24.0% SO. HF-Cb and HF-CLAb diets contained 0.075% and 0.235% of cis-9, trans-11 CLA, respectively. RESULTS: HF-CLAb-fed rats had lower serum insulin levels at fasting than those fed with the HF-Cb diet, while the PPARγ protein levels in adipose tissue was increased in HF-CLAb-fed rats compared to HF-Cb-fed rats. Furthermore, R-QUICK was lower in HF-Cb than in NF-So group, while no differences in R-QUICK were observed among NF-So, HF-CLAb and HF-So groups. Serum HDL cholesterol levels were higher in HF-CLAb-fed rats than in those fed NF-So, HF-Cb and HF-So diets, as well as higher in NF-So-fed rats than in HF-Cb and HF-So-fed rats. HF-CLAb, HF-Cb and HF-So diets reduced serum LDL cholesterol levels when compared to NF-So, whereas serum triacylglycerol levels were increased in HF-CLAb. CONCLUSION: Feeding rats on a high-fat diet containing butter naturally enriched in cis-9, trans-11 CLA prevented hyperinsulinemia and increased HDL cholesterol, which could be associated with higher levels of cis-9, trans-11 CLA, vaccenic acid, oleic acid and lower levels of short and medium-chain saturated fatty acids from butter naturally modified compared to control butter. On the other hand CLA-enriched butter also increased serum triacylglycerol levels, which could be associated with concomitant increases in the content of trans-9 and trans-10 C18:1 isomers in the CLA-enriched butter.

Can mothers consume caffeine? The issue of early life exposure and metabolic changes in offspring.

Caffeine is a substance with central and metabolic effects. Although it is recommended that its use be limited during pregnancy, many women continue to consume caffeine. Direct and indirect actions of caffeine in fetuses and newborns promote adaptive changes, according to the Developmental Origins of Health and Diseases (DOHaD) concept. In fact, epidemiological and experimental evidence reveals the impact of early caffeine exposure. Here, we reviewed these findings with an emphasis on experimental models with rodents. The similarity of human and rodent caffeine metabolism allows the comprehension of molecular mechanisms affected by prenatal caffeine exposure. Maternal caffeine intake affects the body weight and endocrine system of offspring at birth and has long-term effects on the endocrine system, liver function, glucose and lipid metabolism, the cardiac system, the reproductive system, and behavior. Interestingly, some of these effects are sex dependent. Thus, the dose of caffeine considered safe for pregnant women may not be adequate for the prenatal period.

Revisiting pancreatic islet isolation in murine models: A practical and effective technical protocol.

The endocrine pancreas is composed of clusters of cell groups called pancreatic islets. These cells are responsible for the synthesis and secretion of hormones crucial for glycemic homeostasis, such as insulin and glucagon. Therefore, these cells were the targets of many studies. One method to study and/or understand endocrine pancreatic physiology is the isolation of these islets and stimulation of hormone production using different concentrations of glucose, agonists, and/or antagonists of specific secretagogues and mimicking the stimulation of hormonal synthesis and secretion. Many researchers studied pancreatic physiology in murine models due to their ease of maintenance and rapid development. However, the isolation of pancreatic islets involves meticulous processes that may vary between rodent species. The present study describes a simple and effective technical protocol for isolating intact islets from mice and rats for use as a practical guide for researchers. The method involves digestion of the acinar parenchyma by intraductal collagenase. Isolated islets are suitable for in vitro endocrine secretion analyses, microscopy techniques, and biochemical analyses.