Short- and long-term effects of a maternal low-protein diet on ventilation, O₂/CO₂ chemoreception and arterial blood pressure in male rat offspring

Multigenerational inheritance of breathing deficits following perinatal exposure to titanium dioxide nanoparticles in the offspring of mice

BACKGROUND

The utilization of titanium dioxide nanoparticles (TIO2NPs) has experienced a significant surge in recent decades, and these particles are now commonly found in various everyday consumer products. Due to their small size, TIO2NPs can penetrate biological barriers and elicit adverse interactions with biological tissues. Notably, exposure of pregnant females to TIO2NPs during the perinatal period has been shown to disrupt the growth of offspring. Furthermore, this exposure induces epigenetic modifications in the DNA of newborns, suggesting the possibility of multigenerational effects. Thus, perinatal exposure to TIO2NPs may induce immediate metabolic impairments in neonates, which could be transmitted to subsequent generations in the long term.

RESULTS

In this study, we utilized perinatal exposure of female mice to TIO2NPs through voluntary food intake and observed impaired metabolism in newborn male and female F1 offspring. The exposed newborn mice exhibited reduced body weight gain and a slower breathing rate compared to non-exposed animals. Additionally, a higher proportion of exposed F1 newborns experienced apneas. Similar observations were made when the exposure was limited to the postnatal period, highlighting lactation as a critical period for the adverse effects of TIO2NPs on postnatal metabolism. Importantly, the breathing deficits induced by TIO2NPs were transmitted from F1 females to the subsequent F2 generation. Moreover, re-exposure of adult F1 females to TIO2NPs exacerbated the breathing deficits in newborn F2 males.

CONCLUSIONS

Our findings demonstrate that perinatal exposure to TIO2NPs disrupts postnatal body weight gain and respiration in the offspring, and these deficits are transmissible to future generations.

Evolutionary adaptation to juvenile malnutrition impacts adult metabolism and impairs adult fitness in Drosophila

Juvenile undernutrition has lasting effects on adult metabolism of the affected individuals, but it is unclear how adult physiology is shaped over evolutionary time by natural selection driven by juvenile undernutrition. We combined RNAseq, targeted metabolomics, and genomics to study the consequences of evolution under juvenile undernutrition for metabolism of reproductively active adult females of Drosophila melanogaster. Compared to Control populations maintained on standard diet, Selected populations maintained for over 230 generations on a nutrient-poor larval diet evolved major changes in adult gene expression and metabolite abundance, in particular affecting amino acid and purine metabolism. The evolved differences in adult gene expression and metabolite abundance between Selected and Control populations were positively correlated with the corresponding differences previously reported for Selected versus Control larvae. This implies that genetic variants affect both stages similarly. Even when well fed, the metabolic profile of Selected flies resembled that of flies subject to starvation. Finally, Selected flies had lower reproductive output than Controls even when both were raised under the conditions under which the Selected populations evolved. These results imply that evolutionary adaptation to juvenile undernutrition has large pleiotropic consequences for adult metabolism, and that they are costly rather than adaptive for adult fitness. Thus, juvenile and adult metabolism do not appear to evolve independently from each other even in a holometabolous species where the two life stages are separated by a complete metamorphosis.

Evidence for Quercetin as a Dietary Supplement for the Treatment of Cardio-Metabolic Diseases in Pregnancy: A Review in Rodent Models

Quercetin supplementation during pregnancy and lactation has been linked to a lower risk of maternal cardio-metabolic disorders such as gestational diabetes mellitus (GDM), dyslipidemia, preeclampsia, attenuation of malnutrition-related conditions, and gestational obesity in animal studies. Pre-clinical studies have shown that maternal supplementation with quercetin reduces cardio-metabolic diseases in dams and rodents’ offspring, emphasizing its role in modifying phenotypic plasticity. In this sense, it could be inferred that quercetin administration during pregnancy and lactation is a viable strategy for changing cardio-metabolic parameters throughout life. Epigenetic mechanisms affecting the AMP-activated protein kinase (AMPK), nuclear factor-kappa B (NF-κB), and phosphoinositide 3-kinase (PI3 K) pathways could be associated with these changes. To highlight these discoveries, this review outlines the understanding from animal studies investigations about quercetin supplementation and its capacity to prevent or decrease maternal and offspring cardio-metabolic illnesses and associated comorbidities.

Cardiometabolic Effects of Postnatal High-Fat Diet Consumption in Offspring Exposed to Maternal Protein Restriction In Utero

In recent decades, the high incidence of infectious and parasitic diseases has been replaced by a high prevalence of chronic and degenerative diseases. Concomitantly, there have been profound changes in the behavior and eating habits of families around the world, characterizing a "nutritional transition" phenomenon, which refers to a shift in diet in response to modernization, urbanization, or economic development from undernutrition to the excessive consumption of hypercaloric and ultra-processed foods. Protein malnutrition that was a health problem in the first half of the 20th century has now been replaced by high-fat diets, especially diets high in saturated fat, predisposing consumers to overweight and obesity. This panorama points us to the alarming coexistence of both malnutrition and obesity in the same population. In this way, individuals whose mothers were undernourished early in pregnancy and then exposed to postnatal hyperlipidic nutrition have increased risk factors for developing metabolic dysfunction and cardiovascular diseases in adulthood. Thus, our major aim was to review the cardiometabolic effects resulting from postnatal hyperlipidic diets in protein-restricted subjects, as well as to examine the epigenetic repercussions occasioned by the nutritional transition.

Protein Restriction in the Peri-Pubertal Period Induces Autonomic Dysfunction and Cardiac and Vascular Structural Changes in Adult Rats

Perturbations to nutrition during critical periods are associated with changes in embryonic, fetal or postnatal developmental patterns that may render the offspring more likely to develop cardiovascular disease in later life. The aim of this study was to evaluate whether autonomic nervous system imbalance underpins in the long-term hypertension induced by dietary protein restriction during peri-pubertal period. Male Wistar rats were assigned to groups fed with a low protein (4% protein, LP) or control diet (20.5% protein; NP) during peri-puberty, from post-natal day (PN) 30 until PN60, and then all were returned to a normal protein diet until evaluation of cardiovascular and autonomic function at PN120. LP rats showed long-term increased mean arterial pressure (p = 0.002) and sympathetic arousal; increased power of the low frequency (LF) band of the arterial pressure spectral (p = 0.080) compared with NP animals. The depressor response to the ganglion blocker hexamethonium was increased in LP compared with control animals (p = 0.006). Pulse interval variability showed an increase in the LF band and LF/HF ratio (p = 0.062 and p = 0.048) in LP animals. The cardiac response to atenolol and/or methylatropine and the baroreflex sensitivity were similar between groups. LP animals showed ventricular hypertrophy (p = 0.044) and increased interstitial fibrosis (p = 0.028) compared with controls. Reduced protein carbonyls (PC) (p = 0.030) and catalase activity (p = 0.001) were observed in hearts from LP animals compared with control. In the brainstem, the levels of PC (p = 0.002) and the activity of superoxide dismutase and catalase (p = 0.044 and p = 0.012) were reduced in LP animals, while the levels of GSH and total glutathione were higher (p = 0.039 and p = 0.038) compared with NP animals. Protein restriction during peri-pubertal period leads to hypertension later in life accompanied by sustained sympathetic arousal, which may be associated with a disorganization of brain and cardiac redox state and structural cardiac alteration.

Potentially Probiotic Limosilactobacillus fermentum Fruit-Derived Strains Alleviate Cardiometabolic Disorders and Gut Microbiota Impairment in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption is a risk factor for dyslipidemias, insulin resistance, and arterial hypertension linked with gut dysbiosis. Probiotic administration has been suggested as a safe therapeutic strategy for gut microbiota modulation and treatment and/or prevention of cardiometabolic disorders. Here, we assessed the effects of a potentially probiotic formulation containing strains of the Limosilactobacillus (L.) fermentum 139, 263, and 296 on the cardiometabolic disorders and gut microbiota derangements provoked by the HFD consumption. Male Wistar rats were allocated into control diet (CTL, n = 6), HFD (n = 6), and HFD receiving L. fermentum formulation (HFD-LF, n = 6) groups for 4 weeks. L. fermentum formulation (10⁹ colony-forming unit (CFU)/ml of each strain) was daily administered by oral gavage. After 4-week follow-up, biochemical measurements, blood pressure (BP), heart rate (HR), sympathetic tone, and gut microbiota composition were evaluated. HFD consumption for 4 weeks increased lipid profile, insulin resistance, sympathetic tone, and blood pressure and impaired gut microbiota composition in male rats. Administration of L. fermentum formulation improved the gut microbiota composition, lipid profile, insulin resistance, autonomic dysfunction, and BP in rats fed with a HFD. Administration of a potentially fruit-derived probiotic formulation of L. fermentum strains improved gut microbiota composition and alleviated hyperlipidemia, insulin resistance, and sympathetic hyperactivity and increased BP in rats fed a HFD. Our findings may encourage the development of randomized controlled trials to assess the effects of L. fermentum treatment in subjects with cardiometabolic disorders.

Prenatal exercise reprograms the development of hypertension progress and improves vascular health in SHR offspring

BACKGROUND

Upregulation of L-type voltage-gated Ca²⁺ (Ca_V1.2) channel in the arterial myocytes is a hallmark feature of hypertension. However, whether maternal exercise during pregnancy has a sustained beneficial effect on the offspring of spontaneously hypertensive rats (SHRs) through epigenetic regulation of Ca_V1.2 channel is largely unknown.

METHODS

Pregnant SHRs and Wistar-Kyoto rats were subjected to swimming and the vascular molecular and functional properties of male offspring were evaluated at embryonic (E) 20.5 day, 3 months (3 M), and 6 months (6 M).

RESULTS

Exercise during pregnancy significantly decreased the resting blood pressure at 3 M but not 6 M in the offspring of SHR. Prenatal exercise significantly reduced the cardiovascular reactivity, the contribution of Ca_V1.2 channel to the vascular tone, and the whole-cell current density of Ca_V1.2 channel in both 3 M and 6 M offspring of SHR. Moreover, maternal exercise triggered hypermethylation of the promoter region of the Ca_V1.2 α1C gene (CACNA1C), with a concomitant decrease in its protein and mRNA expressions in SHR offspring at E20.5, 3 M, and 6 M. Tissue culture experiments further confirmed that 5-Aza-2'-deoxycytidine increased the structure and functional expression of Ca_V1.2 channel by inhibiting the DNA methylation of CACNA1C. However, the improvement of prenatal exercise on the blood pressure, function, and expression of Ca_V1.2 channel was attenuated in the offspring of SHRs at 6 M compared to the 3 M readout.

CONCLUSIONS

These data suggest that prenatal exercise improves the vascular function by the hypermethylation of CACNA1C in the arterial myocytes and delays the development of hypertension in the offspring of SHRs. However, these effects fade out with age.

Effects of maternal low-protein diet and spontaneous physical activity on the transcription of neurotrophic factors in the placenta and the brains of mothers and offspring rats

Maternal protein restriction and physical activity can affect the interaction mother-placenta-fetus. This study quantified the gene expression of brain-derived neurotrophic factor (BDNF), neurothrophin 4, tyrosine kinase receptor B (TrkB/NTRK2), insulin-like growth factor (IGF-1), and insulin-like growth factor receptor (IGF-1r) in the different areas of mother's brain (hypothalamus, hippocampus, and cortex), placenta, and fetus' brain of rats. Female Wistar rats (n = 20) were housed in cages containing a running wheel for 4 weeks before gestation. According to the distance spontaneously traveled daily, rats were classified as inactive or active. During gestation, on continued access to the running wheel, active and inactive groups were randomized to receive normoprotein diet (18% protein) or a low-protein (LP) diet (8% protein). At day 20 of gestation, gene expression of neurotrophic factors was analyzed by quantitative polymerase chain reaction in different brain areas and the placenta. Dams submitted to a LP diet during gestation showed upregulation of IGF-1r and BDNF messenger RNA in the hypothalamus, IGF-1r and NTRK2 in the hippocampus, and BDNF, NTRK2, IGF-1 and IGF-1r in the cortex. In the placenta, there was a downregulation of IGF-1. In the brain of pups from mothers on LP diet, IGF-1r and NTRK2 were downregulated. Voluntary physical activity attenuated the effects of LP diet on IGF-1r in the hypothalamus, IGF-1r and NTRK2 in the hippocampus, IGF-1 in the placenta, and NTRK2 in the fetus' brain. In conclusion, both maternal protein restriction and spontaneous physical activity influence the gene expression of BDNF, NTRK2, IGF-1, and IGF-1r, with spontaneous physical activity being able to normalize in part the defects caused by protein restriction during pregnancy.

Effects of maternal protein restriction on central and peripheral renin-angiotensin systems in male rat offspring

AIMS

We investigated the involvement of the renin angiotensin system (RAS) on the cardiorespiratory control in rats from dams fed with a low-protein diet.

MAIN METHODS

Male offspring were obtained from dams fed a normoprotein diet (NP, 17% casein) and low-protein diet (LP, 8% casein) during pregnancy and lactation. Direct measurements of arterial pressure (AP), heart rate (HR) and respiratory frequency (RF) were recorded in awake 90-day-old at resting and after losartan potassium through either intracerebroventricular (ICV) microinjections or intravenous (IV) administration. Cardiovascular variability was evaluated by spectral analysis. Peripheral chemoreflex sensitivity was assessed through the potassium cyanide (KCN; 40 μg/0.1 ml/rat, IV). Gene expression was evaluated by qPCR, and MAPK (Mitogen Activated Protein Kinase) expression was evaluated by western blot.

KEY FINDINGS

The LP offspring had higher mean AP (MAP) and RF than NP offspring. In the spectral analysis, the LP rats also showed higher low frequency of systolic AP (NP: 2.7 ± 0.3 vs. LP: 5.0 ± 1.0 mmHg). After ICV losartan, MAP and RF in LP rats remained higher than those in NP rats, but without changes in HR. The peripheral chemoreflex was similar between the groups. LP group had lower gene expression of Rac1 (Ras-related C3 botulinum toxin substrate 1) (NP: 1.13 ± 0.06 vs. LP: 0.88 ± 0.08). Peripherally, LP rats had larger delta of MAP after IV losartan (NP: -9.8 ± 2 vs. LP: -23 ± 6 mmHg), without changes in HR and RF.

SIGNIFICANCE

In rats, the RAS participates peripherally, but not centrally, in the maintenance of arterial hypertension in male offspring induced by maternal protein restriction.

Maternal low protein diet induces persistent expression changes in metabolic genes in male rats

BACKGROUND

Perinatal exposure to a poor nutritional environment predisposes the progeny to the development of metabolic disease at the adult age, both in experimental models and humans. Numerous adaptive responses to maternal protein restriction have been reported in metabolic tissues. However, the expression of glucose/fatty acid metabolism-related genes in adipose tissue and liver needs to be described.

AIM

To evaluate the metabolic impact of perinatal malnutrition, we determined malnutrition-associated gene expression alterations in liver and adipose tissue.

METHODS

In the present study, we evaluated the alterations in gene expression of glycolytic/Krebs cycle genes (Pyruvate dehydrogenase kinase 4 and citrate synthase), adipogenic and lipolytic genes and leptin in the adipose tissue of offspring rats at 30 d and 90 d of age exposed to maternal isocaloric low protein (LP) diet throughout gestation and lactation. We also evaluated, in the livers of the same animals, the same set of genes as well as the gene expression of the transcription factors peroxisome proliferator-activated receptor gamma coactivator 1, forkhead box protein O1 and hepatocyte nuclear factor 4 and of gluconeogenic genes.

RESULTS

In the adipose tissue, we observed a transitory (i.e., at 30 d) downregulation of pyruvate dehydrogenase kinase 4, citrate synthase and carnitine palmitoyl transferase 1b gene expression. Such transcriptional changes did not persist in adult LP rats (90 d), but we observed a tendency towards a decreased gene expression of leptin (P = 0.052). The liver featured some gene expression alterations comparable to the adipose tissue, such as pyruvate dehydrogenase kinase 4 downregulation at 30 d and displayed other tissue-specific changes, including citrate synthase and fatty acid synthase upregulation, but pyruvate kinase downregulation at 30 d in the LP group and carnitine palmitoyl transferase 1b downregulation at 90 d. These gene alterations, together with previously described changes in gene expression in skeletal muscle, may account for the metabolic adaptations in response to maternal LP diet and highlight the occurrence of persistent transcriptional defects in key metabolic genes that may contribute to the development of metabolic alterations during the adult life as a consequence of perinatal malnutrition.

CONCLUSION

We conclude that perinatal malnutrition relays long-lasting transcriptional alterations in metabolically active organs, i.e., liver and adipose tissue.

The probiotic Lactobacillus fermentum 296 attenuates cardiometabolic disorders in high fat diet-treated rats

BACKGROUND AND AIM

High-fat (HF) diet consumption has been associated with gut dysbiosis and increased risk of dyslipidemia, type 2 diabetes mellitus and hypertension. Probiotic administration has been suggested as a safe therapeutic strategy for the treatment of cardiometabolic disorders. This study was designed to assess the effects of probiotic Lactobacillus (L.) fermentum 296, a fruit-derived bacteria strain, against cardiometabolic disorders induced by HF diet.

METHODS AND RESULTS

Male Wistar rats were divided into control diet (CTL); HF diet; and HF diet treated with Lactobacillus fermentum 296 (HF + Lf 296). The L. fermentum 296 strain at 1 × 10⁹ colony forming units (CFU)/ml were daily administered by oral gavage for 4 weeks. The results showed that rats fed with HF diet displayed insulin resistance, reduced Lactobacillus spp. counts in feces, serum lipids, and oxidative profile. Rats fed on HF diet also demonstrated augmented blood pressure associated with sympathetic hyperactivity and impaired baroreflex control. The administration of L. fermentum 296 for 4 weeks recovered fecal Lactobacillus sp. counts and alleviated hyperlipidemia, sympathetic hyperactivity, and reduced systolic blood pressure in HF rats without affecting baroreflex sensibility.

CONCLUSION

Our results suggest the ability of L. fermentum 296 improve biochemical and cardiovascular parameters altered in cardiometabolic disorders.

Maternal physical activity prevents the overexpression of hypoxia-inducible factor 1-α and cardiorespiratory dysfunction in protein malnourished rats

Maternal physical activity attenuates cardiorespiratory dysfunctions and transcriptional alterations presented by the carotid body (CB) of rats. Rats performed physical activity and were classified as inactive/active. During gestation and lactation, mothers received either normoprotein (NP-17% protein) or low-protein diet (LP-8% protein). In offspring, biochemical serum levels, respiratory parameters, cardiovascular parameters and the mRNA expression of hypoxia-inducible factor 1-alpha (HIF-1α), tyrosine hydroxylase (TH) and purinergic receptors were evaluate. LP-inactive pups presented lower RF from 1^st to 14^th days old, and higher RF at 30 days than did NP-inactive and NP-active pups. LP-inactive pups presented with reduced serum protein, albumin, cholesterol and triglycerides levels and an increased fasting glucose level compared to those of NP-inactive and NP-active groups. LP and LP-inactive animals showed an increase in the cardiac variability at the Low-Frequency bands, suggesting a major influence of sympathetic nervous activity. In mRNA analyses, LP-inactive animals showed increased HIF-1α expression and similar expression of TH and purinergic receptors in the CB compared to those of NP groups. All these changes observed in LP-inactive pups were reversed in the pups of active mothers (LP-active). Maternal physical activity is able to attenuate the metabolic, cardiorespiratory and HIF-1α transcription changes induced by protein malnutrition.

Maternal dyslipidemia during pregnancy and lactation increases blood pressure and disrupts cardiorespiratory and glucose hemostasis in female rat offspring

Hypertension and metabolic disorders evidenced in adults who have been exposed to nutritional insults during early life may be sex-dependent. We evaluated if blood pressure (BP), cardiorespiratory control, and metabolic parameters are affected in female offspring (FO) from dams fed a dyslipidaemic diet during pregnancy and lactation. FO was obtained from dams who received control (CTL) or dyslipidaemic diets during pregnancy and lactation. The effects of a maternal dyslipidaemic diet on BP, cardiorespiratory control, and biochemical parameters were assessed at 30 and 90 days of age. The experimental protocol based on a dyslipidaemic diet intervention was effective in developing maternal dyslipidemia. At 30 days of age, the FO from dyslipidaemic dams displayed disordered respiratory pattern, enhanced ventilatory response to hypercapnia (P < 0.05), and increased serum levels of total cholesterol and triglycerides (P < 0.05) when compared with CTL female offspring. At 90 days of age, FO from dyslipidaemic dams had augmented BP (P < 0.05), exacerbated cardiorespiratory responses to hypercapnia (P < 0.05), enhanced pressor responses to peripheral chemoreflex activation (P < 0.05), impaired baroreflex (P < 0.05), and larger delta variations in arterial pressure after ganglionic blockade (P < 0.05). Furthermore, during oral glucose and insulin tolerance tests, FO from dyslipidaemic dams exhibited altered glucose tolerance and insulin sensitivity (P < 0.05) when compared with FO from CTL dams. Altered breathing linked to enhanced central and peripheral chemosensitivity, impaired baroreflex, and augmented sympathetic tone may be predisposing factors for increased BP and metabolic disorders in female offspring from dyslipidaemic dams.

Impact of diet on the persistence of early vascular remodeling and stiffening induced by intrauterine growth restriction and a maternal high-fat diet

Intrauterine growth restriction (IUGR) and maternal high-fat diet (HFD) independently predispose offspring to hypertension. In a rat model, IUGR more so than maternal HFD increases arterial stiffness with vascular remodeling as early as postnatal day (PND) 21. The trajectory of such early vascular changes remains unknown. We hypothesized that IUGR would increase blood pressure (BP), arterial stiffness, and markers of ongoing detrimental vascular remodeling in adult rats exposed to a maternal HFD regardless of weaning diet. Adult female rats were fed either a regular diet (RD) or an HFD before mating through lactation. IUGR was induced by uterine artery ligation. Offspring were weaned to either a RD or HFD through PND 60. For both control and IUGR rats, this design resulted in the following three diet groups: offspring from RD dams weaned to a RD and offspring from HFD dams weaned to a RD or to an HFD (IHH). In both males and females, only IHH increased systolic BP, but IUGR and HFD both alone and in combination increased arterial stiffness. Aortas contained fewer but thicker elastin bands in IHH rats and IUGR offspring from dams fed an HFD and weaned to a regular diet. IHH increased aortic lysl oxidase protein. In summary, the PND 21 rat mediators of vascular remodeling from IUGR and maternal HFD normalize by PND 60 while changes in elastin and arterial stiffness persist. We speculate that the longer-term risk of hypertension from dietary mediators is augmented by underlying IUGR-induced structural changes to the extracellular matrix.NEW & NOTEWORTHY We report that a combined insult of intrauterine growth restriction and maternal high-fat diet increases the risk of early cardiovascular pathology both independently and in conjunction with a continued high-fat diet in offspring.

Saturated Fatty Acid-Enriched Diet-Impaired Mitochondrial Bioenergetics in Liver From Undernourished Rats During Critical Periods of Development

The nutritional transition that the western population has undergone is increasingly associated with chronic metabolic diseases. In this work, we evaluated a diet rich in saturated fatty acids (hyperlipidic, HL) after weaning of the offspring rats submitted to maternal protein restriction on the hepatic mitochondrial bioenergetics. Wistar rats were mated and during gestation and lactation, mothers received control diets (NP, normal protein content 17%) or low protein (LP, 8% protein). After weaning, rats received either NL (normolipidic) or HL (+59% SFA) diets up to 90 days of life. It was verified that all respiratory states of hepatic mitochondria showed a reduction in the LP group submitted to the post-weaning HL diet. This group also presented greater mitochondrial swelling compared to controls, potentiated after Ca2+ addition and prevented in the presence of EGTA (calcium chelator) and cyclosporin A (mitochondrial permeability transition pore inhibitor). There was also an increase in liver protein oxidation and lipid peroxidation and reduction in catalase and glutathione peroxidase activities in the LP group fed HL diet after weaning. Our data suggest that adult rats subjected to maternal protein restriction were more susceptible to hepatic mitochondrial damage caused by a diet rich in saturated fatty acids post-weaning.

Maternal Protein Restriction in Two Successive Generations Impairs Mitochondrial Electron Coupling in the Progeny's Brainstem of Wistar Rats From Both Sexes

Maternal protein deficiency during the critical development period of the progeny disturbs mitochondrial metabolism in the brainstem, which increases the risk of developing cardiovascular diseases in the first-generation (F1) offspring, but is unknown if this effect persists in the second-generation (F2) offspring. The study tested whether mitochondrial health and oxidative balance will be restored in F2 rats. Male and female rats were divided into six groups according to the diet fed to their mothers throughout gestation and lactation periods. These groups were: (1) normoprotein (NP) and (2) low-protein (LP) rats of the first filial generation (F1-NP and F1-LP, respectively) and (3) NP and (4) LP rats of the second filial generation (F2-NP and F2-LP, respectively). After weaning, all groups received commercial chow and a portion of each group was sacrificed on the 30th day of life for determination of mitochondrial and oxidative parameters. The remaining portion of the F1 group was mated at adulthood and fed an NP or LP diet during the periods of gestation and lactation, to produce progeny belonging to (5) F2R-NP and (6) F2R-LP group, respectively. Our results demonstrated that male F1-LP rats suffered mitochondrial impairment associated with an 89% higher production of reactive species (RS) and 137% higher oxidative stress biomarkers, but that the oxidative stress was blunted in female F1-LP animals despite the antioxidant impairment. In the second generation following F0 malnutrition, brainstem antioxidant defenses were restored in the F2-LP group of both sexes. However, F2R-LP offspring, exposed to LP in the diets of the two preceding generations displayed a RS overproduction with a concomitant decrease in mitochondrial bioenergetics. Our findings demonstrate that nutritional stress during the reproductive life of the mother can negatively affect mitochondrial metabolism and oxidative balance in the brainstem of F1 progeny, but that restoration of a normal diet during the reproductive life of those individuals leads toward a mitochondrial recovery in their own (F2) progeny. Otherwise, if protein deprivation is continued from the F0 generation and into the F1 generation, the F2 progeny will exhibit no recovery, but instead will remain vulnerable to further oxidative damage.

A maternal low-protein diet and neonatal overnutrition result in similar changes to glomerular morphology and renal cortical oxidative stress measures in male Wistar rats

There is a strong correlation between inadequate gestational and postpartum nutrition and the occurrence of cardiovascular diseases. The present study investigated the effects of a maternal low-protein diet and neonatal overfeeding on the oxidative balance and morphology of the renal cortex of male Wistar rats. Two independent protocols were used. First, pregnant Wistar rats received diets containing either 17% (normal protein) or 8% (low protein) casein throughout pregnancy and lactation. Second, the litter size was reduced by one-third on the third postnatal day to induce overnourishment in offspring. At 30 days, the oxidative balance and morphology of the renal cortex were analyzed. There was a small but significant increase in renal corpuscle area in the low protein (LP, 5%) and overnutrition (ON, 8%) groups. Glomerular tuft area also increased in LP (6%) and ON (9%), as did glomerular cellularity (LP, +11%; ON, +12%). In the oxidative stress analyses, both nutritional insults significantly elevated lipid peroxidation (LP, +18%; ON, +135%) and protein oxidation (LP, +40%; ON, +65%) while significantly reducing nonenzymatic antioxidant defenses, measured as reduced glutathione (LP, –32%; ON, –45%) and total thiol content (LP, –28%; ON, –24%). We also observed a decrease in superoxide dismutase (LP, –78%; ON, –51%), catalase (LP, –18%; ON, –61%), and glutathione S-transferase (only in ON, –44%) activities. Our results demonstrate that nutritional insults, even those of a very different nature, during perinatal development can result in similar changes in oxidative parameters and glomerular morphology in the renal cortex.

Composition of a maternal high fat diet rich in satured fats and omega 3 in gestation and lactation for studies with rodents

ABSTRACT Objective To prepare a high fat diet rich in satured fatty acids and supplemented with omega 3 for experimental studies in rodents. Methods Purified industrial ingredients and flaxseed oil as a source of omega 3 at a concentration of 3.5% (v/w) were used in the elaboration of the diets. Centesimal and nutritional compositions, fatty acids profile and dietary intake were evaluated. Serum levels of total protein, albumin, cholesterol and glucose in pregnant rats were verified. The offspring were assessed with regard to body mass and waist circumference. Statistical analysis was performed using the Kolmogorov-Smirnov, Anova One-Way test and Bonferroni post-test. Results High fat and high fat with omega 3 diets presented, respectively, 37% and 36% saturated fat, and the lipid amount was 80% higher than the American Institute of Nutrition 93G control diet. The omega 3 content was 50% higher in the high fat with omega 3 diet. There was no difference in consumption of diet types in weight (grams). The dams that received the High fat diet developed hypercholesterolemia and their High fat offspring exhibited higher body mass on the 1st day of life and increased abdominal circumference on the 30th day of life compared to the control and the high fat with omega 3 offspring. Conclusion The formulated diets with a higher amount of saturated fatty acids meet the nutritional requirements of the gestation and lactation period. The high fat diet with omega 3 was able to attenuate the changes observed in dams and their offspring.

Carotid body removal normalizes arterial blood pressure and respiratory frequency in offspring of protein-restricted mothers

The aim of this study is to evaluate the short-term and long-term effects elicited by carotid body removal (CBR) on ventilatory function and the development of hypertension in the offspring of malnourished rats. Wistar rats were fed a normo-protein (NP, 17% casein) or low-protein (LP, 8% casein) diet during pregnancy and lactation. At 29 days of age, the animals were submitted to CBR or a sham surgery, according to the following groups: NP-cbr, LP-cbr, NP-sham, or LP-sham. In the short-term, at 30 days of age, the respiratory frequency (RF) and immunoreactivity for Fos on the retrotrapezoid nucleus (RTN; brainstem site containing CO₂ sensitive neurons) after exposure to CO₂ were evaluated. In the long term, at 90 days of age, arterial pressure (AP), heart rate (HR), and cardiovascular variability were evaluated. In the short term, an increase in the baseline RF (~6%), response to CO₂ (~8%), and Fos in the RTN (~27%) occurred in the LP-sham group compared with the NP-sham group. Interestingly, the CBR in the LP group normalized the RF in response to CO₂ as well as RTN cell activation. In the long term, CBR reduced the mean AP by ~20 mmHg in malnourished rats. The normalization of the arterial pressure was associated with a decrease in the low-frequency (LF) oscillatory component of AP (~58%) and in the sympathetic tonus to the cardiovascular system (~29%). In conclusion, carotid body inputs in malnourished offspring may be responsible for the following: (i) enhanced respiratory frequency and CO₂ chemosensitivity in early life and (ii) the production of autonomic imbalance and the development of hypertension.

Near to One's Heart: The Intimate Relationship Between the Placenta and Fetal Heart

The development of the fetal heart is exquisitely controlled by a multitude of factors, ranging from humoral to mechanical forces. The gatekeeper regulating many of these factors is the placenta, an external fetal organ. As such, resistance within the placental vascular bed has a direct influence on the fetal circulation and therefore, the developing heart. In addition, the placenta serves as the interface between the mother and fetus, controlling substrate exchange and release of hormones into both circulations. The intricate relationship between the placenta and fetal heart is appreciated in instances of clinical placental pathology. Abnormal umbilical cord insertion is associated with congenital heart defects. Likewise, twin-to-twin transfusion syndrome, where monochorionic twins have unequal sharing of their placenta due to inter-twin vascular anastomoses, can result in cardiac remodeling and dysfunction in both fetuses. Moreover, epidemiological studies have suggested a link between placental phenotypic traits and increased risk of cardiovascular disease in adult life. To date, the mechanistic basis of the relationships between the placenta, fetal heart development and later risk of cardiac dysfunction have not been fully elucidated. However, studies using environmental exposures and gene manipulations in experimental animals are providing insights into the pathways involved. Likewise, surgical instrumentation of the maternal and fetal circulations in large animal species has enabled the manipulation of specific humoral and mechanical factors to investigate their roles in fetal cardiac development. This review will focus on such studies and what is known to date about the link between the placenta and heart development.

Low-protein diet does not alter reproductive, biochemical, and hematological parameters in pregnant Wistar rats

The aim of this study was to investigate the reproductive, biochemical, and hematological outcomes of pregnant rats exposed to protein restriction. Wistar rat dams were fed a control normal-protein (NP, 17% protein, n=8) or a low-protein (LP, 8% protein, n=14) diet from the 1st to the 20th day of pregnancy. On the 20th day, the clinical signs of toxicity were evaluated. The pregnant rats were then anesthetized and blood samples were collected for biochemical-hematological analyses, and laparotomy was performed to evaluate reproductive parameters. No sign of toxicity, or differences (P>0.05) in body weight gain and biochemical parameters (urea, creatinine, albumin, globulin, and total protein) between NP and LP pregnant dams were observed. Similarly, hematological data, including red blood cell count, white blood cell count, hemoglobin, hematocrit, red blood cell distribution width (coefficient of variation), mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, % lymphocytes, absolute lymphocyte count, platelet count, and mean platelet volume were similar (P>0.05) at the end of pregnancy. Reproductive parameters (the dam-offspring relationship, ovary mass, placenta mass, number of corpora lutea, implantation index, resorption index, and the pre- and post-implantation loss rates) were also not different (P>0.05) between NP and LP pregnant dams. The present data showed that a protein-restricted diet during pregnancy did not alter reproductive, biochemical, and hematological parameters and seems not to have any toxic effect on pregnant Wistar rats.

Mitochondrial dysfunction: maternal protein restriction as a trigger of reactive species overproduction and brainstem energy failure in male offspring brainstem

Mitochondria are important organelles in eukaryotic organisms, wherein their capacity to produce energy vary among the tissues depending upon the amounts of oxygen consumed. Part of the oxygen consumed during ATP generation produces reactive oxygen species, which if not efficiently removed can trigger a systemic damage to molecular compounds characterized as oxidative stress. Several studies have demonstrated that mitochondrial dysfunction and oxidative stress in the central nervous system (CNS) are related to a plethora of neural disorders. Herein, we hypothesize that a late autonomic imbalance-induced hypertension might be related to long-lasting effects of protein restriction during the critical period of the CNS development on the mitochondrial function and oxidative stress in the brainstem of adult (i.e. 150 days of age) male Wistar rats. Maternal protein restriction was induced by offering a diet based on 8% of casein from first day of pregnancy until weaning, when the male pups started to receive laboratory chow up to 150 days of life. The protein restriction induced an extended detrimental modulation in mitochondria function, decreasing the phosphorylation capacity with concomitant decrease in the mitochondrial membrane potential, wherein the reactive species overproduction triggered a disruption in proton conductance, which may gradually compromise mitochondria energy conservation. Interestingly, the elevated activity of glutathione-S-transferase and the augmented expression of uncoupling protein 2 are likely protective mechanisms induced by lipid peroxidation products, being feasible molecular changes attempting to deal with oxidative stress-induced ageing.

Maternal protein malnutrition induced-hypertension: New evidence about the autonomic and respiratory dysfunctions and epigenetic mechanisms

Maternal protein malnutrition during the critical stages of development (pregnancy, lactation and first infancy) can lead to adult hypertension. Studies have shown that renal and cardiovascular dysfunctions can be associated to the development of hypertension in humans and rats exposed to maternal protein malnutrition. The etiology of hypertension, however, includes a complex network involved in central and peripheral blood pressure control. Recently, the hyperactivity of the sympathetic nervous system in protein-restricted rats has been reported. Studies have shown that protein malnutrition during pregnancy and/or lactation alters blood pressure control through mechanisms that include central sympathetic-respiratory dysfunctions and epigenetic modifications, which may contribute to adult hypertension. Thus, this review will discuss the historical context, new evidences of neurogenic disruption in respiratory-sympathetic activities and possible epigenetic mechanisms involved in maternal protein malnutrition induced- hypertension.

Protective effects of estrogen against cardiovascular disease mediated via oxidative stress in the brain

During their reproductive years women produce significant levels of estrogens, predominantly in the form of estradiol, that are thought to play an important role in cardioprotection. Mechanisms underlying this action include both estrogen-mediated changes in gene expression, and post-transcriptional activation of protein signaling cascades in the heart and in neural centers controlling cardiovascular function, in particular, in the brainstem. There, specific neurons, especially those of the bulbar region play an important role in the neuronal control of the cardiovascular system because they control the outflow of sympathetic activity and parasympathetic activity as well as the reception of chemical and mechanical signals. In the present review, we discuss how estrogens exert their cardioprotective effect in part by modulating the actions of internally generated products of cellular oxidation such as reactive oxygen species (ROS) in brain stem neurons. The significance of this review is in integrating the literature of oxidative damage in the brain with the literature of neuroprotection by estrogen in order to better understand both the benefits and limitations of using this hormone to prevent cardiovascular disease.

Effect of maternal dyslipidaemia on the cardiorespiratory physiology and biochemical parameters in male rat offspring

The present study evaluated the effects of maternal dyslipidaemia on blood pressure (BP), cardiorespiratory physiology and biochemical parameters in male offspring. Wistar rat dams were fed either a control (CTL) or a dyslipidaemic (DLP) diet during pregnancy and lactation. After weaning, both CTL and DLP offspring received standard diet. On the 30th and 90th day of life, blood samples were collected for metabolic analyses. Direct measurements of BP, respiratory frequency (RF), tidal volume (VT) and ventilation (VE) under baseline condition, as well as during hypercapnia (7 % CO2) and hypoxia (KCN, 0·04 %), were recorded from awake 90-d-old male offspring. DLP dams exhibited raised serum levels of total cholesterol (TC) (4·0-fold), TAG (2·0-fold), VLDL+LDL (7·7-fold) and reduced HDL-cholesterol (2·4-fold), insulin resistance and hepatic steatosis at the end of lactation. At 30 d of age, the DLP offspring showed an increase in the serum levels of TC (P<0·05) and VLDL+LDL (P<0·05) in comparison with CTL offspring. At 90 d of age, DLP offspring exhibited higher mean arterial pressure (MAP, approximately 34 %). In the spectral analysis, the DLP group showed augmented low-frequency (LF) power and LF:high-frequency (HF) ratio when compared with CTL offspring. In addition, the DLP animals showed a larger delta variation in arterial pressure after administration of the ganglionic blocker (P=0·0003). We also found that cardiorespiratory response to hypercapnia and hypoxia was augmented in DLP offspring. In conclusion, the present data show that maternal dyslipidaemia alters cardiorespiratory physiology and may be a predisposing factor for hypertension at adulthood.

Maternal protein restriction induced-hypertension is associated to oxidative disruption at transcriptional and functional levels in the medulla oblongata

Maternal protein restriction during pregnancy and lactation predisposes the adult offspring to sympathetic overactivity and arterial hypertension. Although the underlying mechanisms are poorly understood, dysregulation of the oxidative balance has been proposed as a putative trigger of neural-induced hypertension. The aim of the study was to evaluate the association between the oxidative status at transcriptional and functional levels in the medulla oblongata and maternal protein restriction induced-hypertension. Wistar rat dams were fed a control (normal protein; 17% protein) or a low protein ((Lp); 8% protein) diet during pregnancy and lactation, and male offspring was studied at 90 days of age. Direct measurements of baseline arterial blood pressure (ABP) and heart rate (HR) were recorded in awakened offspring. In addition, quantitative RT-PCR was used to assess the mRNA expression of superoxide dismutase 1 (SOD1) and 2 (SOD2), catalase (CAT), glutathione peroxidase (GPx), Glutamatergic receptors (Grin1, Gria1 and Grm1) and GABA(A)-receptor-associated protein like 1 (Gabarapl1). Malondialdehyde (MDA) levels, CAT and SOD activities were examined in ventral and dorsal medulla. Lp rats exhibited higher ABP. The mRNA expression levels of SOD2, GPx and Gabarapl1 were down regulated in medullary tissue of Lp rats (P<.05, t test). In addition, we observed that higher MDA levels were associated to decreased SOD (approximately 45%) and CAT (approximately 50%) activities in ventral medulla. Taken together, our data suggest that maternal protein restriction induced-hypertension is associated with medullary oxidative dysfunction at transcriptional level and with impaired antioxidant capacity in the ventral medulla.

Oxidative injuries induced by maternal low-protein diet in female brainstem

Many studies have shown that a maternal low-protein diet increases the susceptibility of offspring to cardiovascular disease in later-life. Moreover, a lower incidence of cardiovascular disease in females than in males is understood to be largely due to the protective effect of high levels of estrogens throughout a woman's reproductive life. However, to our knowledge, the role of estradiol in moderating the later-life susceptibility of offspring of nutrient-deprived mothers to cardiovascular disease is not fully understood. The present study is aimed at investigating whether oxidative stress in the brainstem caused by a maternal low-protein diet administered during a critical period of fetal/neonatal brain development (i.e during gestation and lactation) is affected by estradiol levels. Female Wistar rat offspring were divided into four groups according to their mothers' diets and to the serum estradiol levels of the offspring at the time of testing: (1) 22 days of age/control diet: (2) 22 days of age/low-protein diet; (3) 122 days of age/control diet: (4) 122 days of age/low-protein diet. Undernutrition in the context of low serum estradiol compared to undernutrition in a higher estradiol context resulted in increased levels of oxidative stress biomarkers and a reduction in enzymatic and non-enzymatic antioxidant defenses. Total global oxy-score showed oxidative damage in 22-day-old rats whose mothers had received a low-protein diet. In the 122-day-old group, we observed a decrease in oxidative stress biomarkers, increased enzymatic antioxidant activity, and a positive oxy-score when compared to control. We conclude from these results that following a protein deficiency in the maternal diet during early development of the offspring, estrogens present at high levels at reproductive age may confer resistance to the oxidative damage in the brainstem that is very apparent in pre-pubertal rats.

Effects of high-fat diet on somatic growth, metabolic parameters and function of peritoneal macrophages of young rats submitted to a maternal low-protein diet

This study evaluated the effects of a post-weaning high-fat (HF) diet on somatic growth, food consumption, metabolic parameters, phagocytic rate and nitric oxide (NO) production of peritoneal macrophages in young rats submitted to a maternal low-protein (LP) diet. Male Wistar rats (aged 60 d) were divided in two groups (n 22/each) according to their maternal diet during gestation and lactation: control (C, dams fed 17 % casein) and LP (dams fed 8 % casein). At weaning, half of the groups were fed HF diet and two more groups were formed (HF and low protein-high fat (LP-HF)). Somatic growth, food and energy intake, fat depots, serum glucose, cholesterol and leptin concentrations were evaluated. Phagocytic rate and NO production were analysed in peritoneal macrophages under stimulation of zymosan and lipopolysaccharide (LPS)+interferon γ (IFN-γ), respectively. The maternal LP diet altered the somatic parameters of growth and development of pups. LP and LP-HF pups showed a higher body weight gain and food intake than C pups. HF and LP-HF pups showed increased retroperitoneal and epididymal fat depots, serum level of TAG and total cholesterol compared with C and LP pups. After LPS+IFN-γ stimulation, LP and LP-HF pups showed reduced NO production when compared with their pairs. Increased phagocytic activity and NO production were seen in LP but not LP-HF peritoneal macrophages. However, peritoneal macrophages of LP pups were hyporesponsive to LPS+IFN-γ induced NO release, even after a post-weaning HF diet. Our data demonstrated that there was an immunomodulation related to dietary fatty acids after the maternal LP diet-induced metabolic programming.

Maternal low-protein diet in female rat heart: possible protective effect of estradiol

Several studies have shown that maternal low-protein (LP) diet induces detrimental effects in cardiovascular system and oxidative stress in male animals. Additional studies suggested that female has lower incidence of cardiovascular disease. However until present data, the possible effects of estradiol on the undernutrition during gestational and lactation periods are not discussed. The present study was conducted to evaluate the effects of a maternal LP diet during gestational and lactation period on oxidative balance in the female rat hearts ventricles at two ages. Dams were fed with normal protein (NP) or a LP diet during the gestational and lactation period, and their female offspring were divided into age groups (22 or 122 days, corresponding to a low or high estrogen level) composing four experimental groups. Evaluating the nutritional effect showed an increase in oxidative stress biomarkers and decrease in enzymatic defense in LP-22D compared with NP-22D. In contrast, no changes were observed in malondialdehyde and carbonyls, but an increase in glutathione-S-transferase (GST) activity in the LP-122D compared with NP-122D. The global oxy-score in the LP-22D group indicated a predominance of oxidative damage when compared with NP-22D, while in LP-122D group the global oxy-score was restored to NP-122D levels. Evaluating the estradiol effect, our data show a significant decrease in oxidative stress with increase in CAT and GST activity, associated with increase in intracellular thiols. Our data suggest that in situation with low levels of estradiol, hypoproteic diet during gestation and lactation period has detrimental effects on heart, however when estradiol levels raise, the detrimental effects induced are mitigated.

Deficits in anthropometric indices of nutritional status and motor performance among low birth weight children from Maputo City, Mozambique

OBJECTIVE

To evaluate associations between low birth weight (LBW) and anthropometry, body composition, physical fitness, and gross motor coordination among schoolchildren from Maputo, Mozambique.

METHODS

A total of 353 children aged 7 to 10 years old from both genders born in Maputo (Mozambique) were sampled. The sample was divided into two groups: LBW (n = 155) and normal birth weight (NBW, n = 198). Body composition measurements and indices weight-for-age, height-for-age, and weight-for-height were assessed. Physical fitness was assessed by handgrip strength, flexibility, agility, long jump, and running speed. Gross motor coordination was evaluated by using the Korper Koordination Test fur Kinder (KTK) battery.

RESULTS

LBW children were lighter and smaller than NBW children with reduced indices for weight-for-age and height-for-age. They also showed a reduced performance in handgrip strength and sideways movement tests. These differences remained significant even after adjustment for age, gender, body size, and fatness skinfold thickness.

CONCLUSION

LBW seems to be the major factor that influences anthropometry, and is a predictor of low muscle strength and low performance on sideways movement tests. This result suggests that growth faltering in LBW children is associated with adverse health consequences, even after controlling for gender, age, fatness, and body size.

Changes in cardiovascular responses to chemoreflex activation of rats recovered from protein restriction are not related to AT1 receptors

NEW FINDINGS

What is the central question of this study? In this study, we sought to investigate whether cardiovascular responses to peripheral chemoreflex activation of rats recovered from protein restriction are related to activation of AT₁ receptors. What is the main finding and its importance? This study highlights the fact that angiotensinergic mechanisms activated by AT₁ receptors do not support increased responses to peripheral chemoreflex activation by KCN in rats recovered from protein restriction. Also, we found that protein restriction led to increased resting ventilation in adult rats, even after recovery. The effects of a low-protein diet followed by recovery on cardiorespiratory responses to peripheral chemoreflex activation were tested before and after systemic angiotensin II type 1 (AT₁ ) receptor antagonism. Male Fischer rats were divided into control and recovered (R-PR) groups after weaning. The R-PR rats were fed a low-protein (8%) diet for 35 days and recovered with a normal protein (20%) diet for 70 days. Control rats received a normal protein diet for 105 days (CG₁₀₅ ). After cannulation surgery, mean arterial pressure, heart rate, respiratory frequency, tidal volume and minute ventilation were acquired using a digital recording system in freely moving rats. The role of angintensin II was evaluated by systemic antagonism of AT₁ receptors with losartan (20 mg kg^-1 i.v.). The peripheral chemoreflex was elicited by increasing doses of KCN (20-160 μg kg min^-1 , i.v.). At baseline, R-PR rats presented increased heart rate and minute ventilation (372 ± 34 beats min^-1 and 1.274 ± 377 ml kg^-1  min^-1 ) compared with CG₁₀₅ animals (332 ± 22 beats min^-1 and 856 ± 112 ml kg^-1  min^-1 ). Mean arterial pressure was not different between the groups. Pressor and bradycardic responses evoked by KCN (60 μg kg^-1 ) were increased in R-PR (+45 ± 13 mmHg and -77 ± 47 beats min^-1 ) compared with CG₁₀₅ rats (+25 ± 17 mmHg and -27 ± 28 beats min^-1 ), but no difference was found in the tachypnoeic response. These differences were preserved after losartan. The data suggest that angiotensin II acting on AT₁ receptors may not be associated with the increased heart rate, increased minute ventilation and acute cardiovascular responses to peripheral chemoreflex activation in rats that underwent postweaning protein restriction followed by recovery.

Western diet in the perinatal period promotes dysautonomia in the offspring of adult rats

The present study investigated the impact of a western diet during gestation and lactation on the anthropometry, serum biochemical, blood pressure and cardiovascular autonomic control on the offspring. Male Wistar rats were divided into two groups according to their mother's diet received: control group (C: 18% calories of lipids) and westernized group (W: 32% calories of lipids). After weaning both groups received standard diet. On the 60th day of life, blood samples were collected for the analysis of fasting glucose and lipidogram. Cardiovascular parameters were measured on the same period. Autonomic nervous system modulation was evaluated by spectrum analysis of heart rate (HR) and systolic arterial pressure (SAP). The W increased glycemia (123±2 v. 155±2 mg/dl), low-density lipoprotein (15±1 v. 31±2 mg/dl), triglycerides (49±1 v. 85±2 mg/dl), total cholesterol (75±2 v. 86±2 mg/dl), and decreased high-density lipoprotein (50±4 v. 38±3 mg/dl), as well as increased body mass (209±4 v. 229±6 g) than C. Furthermore, the W showed higher SAP (130±4 v. 157±2 mmHg), HR (357±10 v. 428±14 bpm), sympathetic modulation to vessels (2.3±0.56 v. 6±0.84 mmHg2) and LF/HF ratio (0.15±0.01 v. 0.7±0.2) than C. These findings suggest that a western diet during pregnancy and lactation leads to overweight associated with autonomic misbalance and hypertension in adulthood.

Developmental Origins of Cardiometabolic Diseases: Role of the Maternal Diet

Developmental origins of cardiometabolic diseases have been related to maternal nutritional conditions. In this context, the rising incidence of arterial hypertension, diabetes type II, and dyslipidemia has been attributed to genetic programming. Besides, environmental conditions during perinatal development such as maternal undernutrition or overnutrition can program changes in the integration among physiological systems leading to cardiometabolic diseases. This phenomenon can be understood in the context of the phenotypic plasticity and refers to the adjustment of a phenotype in response to environmental input without genetic change, following a novel, or unusual input during development. Experimental studies indicate that fetal exposure to an adverse maternal environment may alter the morphology and physiology that contribute to the development of cardiometabolic diseases. It has been shown that both maternal protein restriction and overnutrition alter the central and peripheral control of arterial pressure and metabolism. This review will address the new concepts on the maternal diet induced-cardiometabolic diseases that include the potential role of the perinatal malnutrition.

Serum protein concentration in low-dose total body irradiation of normal and malnourished rats

Among the radiotherapeutics' modalities, total body irradiation (TBI) is used as treatment for certain hematological, oncological and immunological diseases. The aim of this study was to evaluate the long-term effects of low-dose TBI on plasma concentration of total protein and albumin using prematurely and undernourished rats as animal model. For this, four groups with 9 animals each were formed: Normal nourished (N); Malnourished (M); Irradiated Normal nourished (IN); Irradiated Malnourished (IM). At the age of 28 days, rats of the IN and IM groups underwent total body gamma irradiation with a source of cobalt-60. Total protein and Albumin in the blood serum was quantified by colorimetry. This research indicates that procedures involving low-dose total body irradiation in children have repercussions in the reduction in body-mass as well as in the plasma levels of total protein and albumin. Our findings reinforce the periodic monitoring of total serum protein and albumin levels as an important tool in long-term follow-up of pediatric patients in treatments associated to total body irradiation.

Mitochondrial bioenergetics and oxidative status disruption in brainstem of weaned rats: Immediate response to maternal protein restriction

Mitochondrial bioenergetics dysfunction has been postulated as an important mechanism associated to a number of cardiovascular diseases in adulthood. One of the hypotheses is that this is caused by the metabolic challenge generated by the mismatch between prenatal predicted and postnatal reality. Perinatal low-protein diet produces several effects that are manifested in the adult animal, including altered sympathetic tone, increased arterial blood pressure and oxidative stress in the brainstem. The majority of the studies related to nutritional programming postulates that the increased risk levels for non-communicable diseases are associated with the incompatibility between prenatal and postnatal environment. However, little is known about the immediate effects of maternal protein restriction on the offspring's brainstem. The present study aimed to test the hypothesis that a maternal low-protein diet causes tissue damage immediately after exposure to the nutritional insult that can be assessed in the brainstem of weaned offspring. In this regard, a series of assays was conducted to measure the mitochondrial bioenergetics and oxidative stress biomarkers in the brainstem, which is the brain structure responsible for the autonomic cardiovascular control. Pregnant Wistar rats were fed ad libitum with normoprotein (NP; 17% casein) or low-protein (LP; 8% casein) diet throughout pregnancy and lactation periods. At weaning, the male offsprings were euthanized and the brainstem was quickly removed to assess the mitochondria function, reactive oxygen species (ROS) production, mitochondrial membrane electric potential (ΔΨm), oxidative biomarkers, antioxidant defense and redox status. Our data demonstrated that perinatal LP diet induces an immediate mitochondrial dysfunction. Furthermore, the protein restriction induced a marked increase in ROS production, with a decrease in antioxidant defense and redox status. Altogether, our findings suggest that LP-fed animals may be at a higher risk for oxidative metabolism impairment throughout life than NP-fed rats, due to the immediate disruption of the mitochondrial bioenergetics and oxidative status caused by the LP diet.

Neonatal SSRI exposure improves mitochondrial function and antioxidant defense in rat heart

Protein restriction during prenatal, postnatal, or in both periods has a close relationship with subsequent development of cardiovascular disease in adulthood. Elevated brain levels of serotonin and its metabolites have been found in malnourished states. The aim in the present study was to investigate whether treatment with fluoxetine (Fx), a selective serotonin reuptake inhibitor, mimics the detrimental effect of low-protein diet during the perinatal period on the male rat heart. Our hypothesis is that increased circulating serotonin as a result of pharmacologic treatment with Fx leads to cardiac dysfunction similar to that observed in protein-restricted rats. Male Wistar rat pups received daily subcutaneous injection of Fx or vehicle from postnatal day 1 to postnatal day 21. Male rats were euthanized at 60 days of age and the following parameters were evaluated in the cardiac tissue: mitochondrial respiratory capacity, respiratory control ratio, reactive oxygen species (ROS) production, mitochondrial membrane potential, and biomarkers of oxidative stress and antioxidant defense. We found that Fx treatment increased mitochondrial respiratory capacity (123%) and membrane potential (212%) and decreased ROS production (55%). In addition we observed an increase in the antioxidant capacity (elevation in catalase activity (5-fold) and glutathione peroxidase (4.6-fold)). Taken together, our results suggest that Fx treatment in the developmental period positively affects the mitochondrial bioenergetics and antioxidant defense in the cardiac tissue.

New Insights on the Maternal Diet Induced-Hypertension: Potential Role of the Phenotypic Plasticity and Sympathetic-Respiratory Overactivity

Systemic arterial hypertension (SAH) is an important risk factor for cardiovascular disease and affects worldwide population. Current environment including life style coupled with genetic programming have been attributed to the rising incidence of hypertension. Besides, environmental conditions during perinatal development such as maternal malnutrition can program changes in the integration among renal, neural, and endocrine system leading to hypertension. This phenomenon is termed phenotypic plasticity and refers to the adjustment of a phenotype in response to environmental stimuli without genetic change, following a novel or unusual input during development. Human and animal studies indicate that fetal exposure to an adverse maternal environment may alter the renal morphology and physiology that contribute to the development of hypertension. Recently, it has been shown that the maternal protein restriction alter the central control of SAH by a mechanism that include respiratory dysfunction and enhanced sympathetic-respiratory coupling at early life, which may contribute to adult hypertension. This review will address the new insights on the maternal diet induced-hypertension that include the potential role of the phenotypic plasticity, specifically the perinatal protein malnutrition, and sympathetic-respiratory overactivity.

The Role of Maternal Dietary Proteins in Development of Metabolic Syndrome in Offspring

The prevalence of metabolic syndrome and obesity has been increasing. Pre-natal environment has been suggested as a factor influencing the risk of metabolic syndrome in adulthood. Both observational and experimental studies showed that maternal diet is a major modifier of the development of regulatory systems in the offspring in utero and post-natally. Both protein content and source in maternal diet influence pre- and early post-natal development. High and low protein dams’ diets have detrimental effect on body weight, blood pressure191 and metabolic and intake regulatory systems in the offspring. Moreover, the role of the source of protein in a nutritionally adequate maternal diet in programming of food intake regulatory system, body weight, glucose metabolism and blood pressure in offspring is studied. However, underlying mechanisms are still elusive. The purpose of this review is to examine the current literature related to the role of proteins in maternal diets in development of characteristics of the metabolic syndrome in offspring.

Perinatal low-protein diet alters brainstem antioxidant metabolism in adult offspring

BACKGROUND AND OBJECTIVES

Studies in humans and animal models have established a close relationship between early environment insult and subsequent risk of development of non-communicable diseases, including the cardiovascular. Whereas experimental evidences highlight the early undernutrition and the late cardiovascular disease relation, the central mechanisms linking the two remain unknown. Owing to the oxidative balance influence in several pathologies, the aim of the present study was to evaluate the effects of maternal undernutrition (i.e. a low-protein (LP) diet) on oxidative balance in the brainstem.

METHODS AND RESULTS

Male rats from mothers fed with an LP diet (8% casein) throughout the perinatal period (i.e. gestation and lactation) showed 10× higher lipid peroxidation levels than animals treated with normoprotein (17% casein) at 100 days of age. In addition, we observed the following reductions in enzymatic activities: superoxide dismutase, 16%; catalase, 30%; glutathione peroxidase, 34%; glutathione-S-transferase, 51%; glutathione reductase, 23%; glucose-6-phosphate dehydrogenase, 31%; and in non-enzymatic glutathione system, 46%.

DISCUSSION

This study is the first to focus on the role of maternal LP nutrition in oxidative balance in a central nervous system structure responsible for cardiovascular control in adult rats. Our data observed changes in oxidative balance in the offspring, therefore, bring a new concept related to early undernutrition and can help in the development of a new clinical strategy to combat the effects of nutritional insult. Wherein the central oxidative imbalance is a feasible mechanism underlying the hypertension risk in adulthood triggered by maternal LP diet.

Birthweight, body composition, and motor performance in 7- to 10-year-old children

AIM

The aim of this study was to analyse the influence of birthweight on motor performance and body composition in children. Further, we investigated whether associations between birthweight and motor performance changed after adjustment for current height, body mass index (BMI), fat-free mass (FFM), and % body fat.

METHOD

A total of 483 children (251 males and 232 females) aged 7 to 10 years (mean 8.78, SD 1.0y) born in Vitória Santo Antão (northeast Brazil) were sampled. Motor performance was operationalized using different physical fitness components and gross motor coordination. Physical fitness was measured by handgrip strength, muscle endurance, explosive power, flexibility, agility, running speed, and maximal oxygen consumption (VO2max). Gross motor coordination was evaluated by means of the Körper Koordination Test für Kinder (KTK).

RESULTS

Positive correlations between birthweight and height, BMI, and FFM were found. Birthweight was positively correlated with handgrip strength and negatively correlated with 20-meter sprint time, even after controlling for age, height, BMI, FFM, and % body fat. Birthweight was negatively associated with relative VO2max (mL/kg/min); however, the association was no longer significant after inclusion of BMI or FFM in the model.

INTERPRETATION

Birthweight significantly predicted height, BMI, FFM, and performance in strength and velocity tests, but did not influence gross motor coordination.

Maternal protein restriction increases respiratory and sympathetic activities and sensitizes peripheral chemoreflex in male rat offspring

BACKGROUND

Maternal protein restriction in rats increases the risk of adult offspring arterial hypertension through unknown mechanisms.

OBJECTIVES

The aims of the study were to evaluate the effects of a low-protein (LP) diet during pregnancy and lactation on baseline sympathetic and respiratory activities and peripheral chemoreflex sensitivity in the rat offspring.

METHODS

Wistar rat dams were fed a control [normal-protein (NP); 17% protein] or an LP (8% protein) diet during pregnancy and lactation, and their male offspring were studied at 30 d of age. Direct measurements of baseline arterial blood pressure (ABP), heart rate (HR), and respiratory frequency (Rf) as well as peripheral chemoreflex activation (potassium cyanide: 0.04%) were recorded in pups while they were awake. In addition, recordings of the phrenic nerve (PN) and thoracic sympathetic nerve (tSN) activities were obtained from the in situ preparations. Hypoxia-inducible factor 1α (HIF-1α) expression was also evaluated in carotid bifurcation through a Western blotting assay.

RESULTS

At 30 d of age, unanesthetized LP rats exhibited enhanced resting Rf (P = 0.001) and similar ABP and HR compared with the NP rats. Despite their similar baseline ABP values, LP rats exhibited augmented low-frequency variability (∼91%; P = 0.01). In addition, the unanesthetized LP rats showed enhanced pressor (P = 0.01) and tachypnoeic (P = 0.03) responses to peripheral chemoreflex activation. The LP rats displayed elevated baseline tSN activity (∼86%; P = 0.02) and PN burst frequency (45%; P = 0.01) and amplitude (53%; P = 0.001) as well as augmented sympathetic (P = 0.01) and phrenic (P = 0.04) excitatory responses to peripheral chemoreflex activation compared with the NP group. Furthermore, LP rats showed an increase of ∼100% in HIF-1α protein density in carotid bifurcation compared with NP rats.

CONCLUSION

Sympathetic-respiratory overactivity and amplified peripheral chemoreceptor responses, potentially through HIF-1α-dependent mechanisms, precede the onset of hypertension in juvenile rats exposed to protein undernutrition during gestation and lactation.

A Short-Term Fasting in Neonates Induces Breathing Instability and Epigenetic Modification in the Carotid Body

The respiratory control system is not fully developed in newborn, and data suggest that adequate nutrition is important for the development of the respiratory control system. Infants need to be fed every 2-4 h to maintain appropriate energy levels, but a skip of feeding can occur due to social economical reasons or mild sickness of infants. Here, we asked questions if a short-term fasting (1) alters carotid body (CB) chemoreceptor activity and integrated function of the respiratory control system; (2) causes epigenetic modification within the respiratory control system. Mouse pups ( Collapse

Key Words

• carotid body
• epigenetics
• fasting
• hypoxia
• mouse
• respiratory control

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MESH Headings

• Animals
• Animals, Newborn
• Carotid Body/physiology
• Epigenesis, Genetic
• Fasting/physiology
• Mice
• Respiration

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Grants

• ES016817 NIEHS NIH HHS
• HL081345 NHLBI NIH HHS
• R00 ES016817 NIEHS NIH HHS
• R01 HL081345 NHLBI NIH HHS
• K99 ES016817 NIEHS NIH HHS

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Affiliation(s)

Machiko Shirahata Department of Environmental Health Sciences, Johns Hopkins University, Baltimore, MD, USA
Wan-Yee Tang Department of Environmental Health Sciences, Johns Hopkins University, Baltimore, MD, USA
Eric W. Kostuk Department of Environmental Health Sciences, Johns Hopkins University, Baltimore, MD, USA

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Collaborators Collapse

Maternal low-protein diet induces changes in the cardiovascular autonomic modulation in male rat offspring

BACKGROUND AND AIMS

Maternal undernutrition induces development of the arterial hypertension. We investigated the effects of a maternal low-protein diet on cardiovascular autonomic control in the offspring.

METHODS AND RESULTS

Male Wistar rats were divided into two groups according to the diets of their mothers during gestation and lactation: the control (normal protein, NP, 17% casein; n = 14) and low-protein (LP, 8% casein; n = 14) groups. Direct measurements of arterial pressure (AP) were recorded from wakeful 90-day-old male offspring. The LP offspring presented higher mean AP than did the NP rats (NP: 93 ± 4 vs. LP: 113 ± 2 mmHg; p < 0.05), whereas the heart rate (HR) was similar in the two groups. In the spectral analysis, the LP group showed higher power at low (NP: 1.98 ± 0.25 vs. LP: 3.7 ± 0.3 mmHg²; p < 0.05) and high (NP: 1.28 ± 0.18 vs. LP: 2.13 ± 0.42 mmHg²; p < 0.05) frequencies of systolic arterial pressure (SAP). In the pulse interval, the LP group presented an increase in the LF/HF ratio (NP: 0.32 vs. LP: 0.56; p < 0.05). After propranolol (4 mg/kg, intravenous (iv)), the bradycardia was higher in the LP group (NP: -36 ± 8 vs. LP: -94 ± 12 bpm; p < 0.05), after methylatropine (2 mg/kg, iv), the tachycardia was similar to NP group. After administration of the ganglionic blocker (hexamethonium; 25 mg/kg, iv), the LP animals showed larger delta variation in the AP (NP: -33.7 ± 5 vs. LP: -53.6 ± 4 mmHg; p < 0.05).

CONCLUSION

The rats subjected to protein malnutrition presented an increase in the cardiovascular sympathetic tone, which contributed to the elevated AP observed in these animals.

The effect of maternal low-protein diet on the heart of adult offspring: role of mitochondria and oxidative stress

Protein restriction during perinatal and early postnatal development is associated with a greater incidence of disease in the adult, such arterial hypertension. The aim in the present study was to investigate the effect of maternal low-protein diet on mitochondrial oxidative phosphorylation capacity, mitochondrial reactive oxygen species (ROS) formation, antioxidant levels (enzymatic and nonenzymatic), and oxidative stress levels on the heart of the adult offspring. Pregnant Wistar rats received either 17% casein (normal protein, NP) or 8% casein (low protein, LP) throughout pregnancy and lactation. After weaning male progeny of these NP or LP fed rats, females were maintained on commercial chow (Labina-Purina). At 100 days post-birth, the male rats were sacrificed and heart tissue was harvested and stored at −80 °C. Our results show that restricting protein consumption in pregnant females induced decreased mitochondrial oxidative phosphorylation capacity (51% reduction in ADP-stimulated oxygen consumption and 49.5% reduction in respiratory control ratio) in their progeny when compared with NP group. In addition, maternal low-protein diet induced a significant decrease in enzymatic antioxidant capacity (37.8% decrease in superoxide dismutase activity; 42% decrease in catalase activity; 44.8% decrease in glutathione-S-transferase activity; 47.9% decrease in glutathione reductase; 25.7% decrease in glucose-6 phosphate dehydrogenase) and glutathione level (34.8% decrease) when compared with control. From these findings, we hypothesize that an increased production of ROS and decrease in antioxidant activity levels induced by protein restriction during development could potentiate the progression of metabolic and cardiac diseases in adulthood.