LP Dams Research Articles

Postnatal growth restriction alters myocardial mitochondrial energetics in mice.

Postnatal growth restriction (PGR) can increase the risk of cardiovascular disease (CVD) potentially due to impairments in oxidative phosphorylation (OxPhos) within cardiomyocyte mitochondria. The purpose of this investigation was to determine if PGR impairs cardiac metabolism, specifically OxPhos. FVB (Friend Virus B-type) mice were fed a normal-protein (NP: 20% protein), or low-protein (LP: 8% protein) isocaloric diet 2weeks before mating. LP dams produce ∼20% less milk, and pups nursed by LP dams experience reduced growth into adulthood as compared to pups nursed by NP dams. At birth (PN1), pups born to dams fed the NP diet were transferred to LP dams (PGR group) or a different NP dam (control group: CON). At weaning (PN21), all mice were fed the NP diet. At PN22 and PN80, mitochondria were isolated for respirometry (oxygen consumption rate, ) and fluorimetry (reactive oxygen species emission, ) analysis measured as baseline respiration (LEAK) and with saturating ADP (OxPhos). Western blotting at PN22 and PN80 determined protein abundance of uncoupling protein 3, peroxiredoxin-6, voltage-dependent anion channel and adenine nucleotide translocator 1 to provide further insight into mitochondrial function. ANOVAs with the main effects of diet, sex and age with α-level of 0.05 was set a priori. Overall, PGR (7.8±1.1) had significant (P=0.01) reductions in respiratory control in complex I when compared to CON (8.9±1.0). In general, our results show that PGR led to higher electron leakage in the form of free radical production and reactive oxygen species emission. No significant diet effects were found in protein abundance. The observed reduced respiratory control and increased ROS emission in PGR mice may increase risk for CVD in mice.

Multiple Early Life Stressors as Risk Factors for Neurodevelopmental Abnormalities in the F1 Wistar Rats.

Cumulative exposure to multiple early life stressors is expected to affect behavioral development, causing increased susceptibility to neuropsychiatric disorders. The present study was designed to mimic such conditions in a rat model to study behavioral impairments during adolescence and adulthood. Female Wistar rats (n = 32; 140-150 gm) were switched to a low protein (LP; 8% protein) or control (20% protein) diet 15 days prior to conception, and then the diet regime was maintained throughout the experimental period. Pups born to control and LP dams were intraperitoneally injected with deltamethrin (DLT-pyrethroid insecticide; 0.7 mg/kg body weight; PND 1 to 7), lipopolysaccharide (LPS-bacterial endotoxin; 0.3 mg/kg body weight; PND 3 and 5), or DLT+LPS, on designated days forming eight experimental groups (Control, LP, Control+LPS, LP+LPS, Control+DLT, LP+DLT, Control+DLT+LPS and LP+DLT+LPS). Neurobehavioral assessments were performed in F1 rats (1, 3, 6 months) by open field, elevated plus maze, light and dark box, and rotarod tests. LP rats were found to be highly susceptible to either singular or cumulative exposure as compared to their age-matched control counterparts, showing significantly severe behavioral abnormalities, such as hyperactivity, attention deficits and low anxiety, the hallmark symptoms of neuropsychiatric disorders like schizophrenia and ADHD, suggesting thereby that early life multi-hit exposure may predispose individuals to developmental disorders.

Prepartum protein supplementation in Angus cows

Cow calf operations in Argentina are managed under extensive grazing condition and the quality of forages is often poor during the second half of gestation. The present work investigated the effects of two levels of crude protein (CP) provided to mature dams during late gestation on their subsequent reproductive performance and milk yield, heifer’s (F1) postweaning growth, reproductive performance, milk production and grand offspring growth (F2). Sixty eight multiparous cows were randomly assigned to either low (LP, 6% CP) or high protein (HP, 12% CP) diets. Body weight (BW) and body condition score (BCS) of cows were determined, and milk production was measured until weaning. In the female, progeny time and BW at puberty, were determined. Reproductive and milk performance of female offspring until weaning, were recorded, as well as their offspring growth until weaning. The HP cows had greater BW gain during the prepartum period (P < 0,01) and tended to gain more BCS (P = 0,06) than LP cows. Pregnancy rates, milk production and composition were not influenced by dietary treatments. At puberty (P = 0,01) and pregnancy diagnosis (P = 0,05), HP heifers were heavier than LP heifers. No dam nutrition effects were found on offspring age at puberty (P = 0,98), final pregnancy rate (P = 0,28) or milk yield (P = 0,76), but heifers born from LP dams had greater milk protein percentage (P = 0,04) and tended to produce more milk fat percentage (P = 0,08) compared with HP heifers. The LP grand offspring grew faster from birth until weaning compared with HP grand offspring (P < 0,01). In conclusion, protein level of the diet during the prepartum period in multiparous beef cows affected the BW change at calving, without consequences on reproductive performance and milk quality and yield. Protein supplementation during late gestation did not affect reproductive performance of the offspring heifers but did impact their BW evolution, milk quality and grand offspring performance. The use of diet with low amount of protein during late gestation can affect progeny development and ability to nourish subsequent generations.

Postnatal Growth Restriction in Mice Alters Cardiac Protein Composition and Leads to Functional Impairment in Adulthood.

Postnatal growth restriction (PGR) increases the risk for cardiovascular disease (CVD) in adulthood, yet there is minimal mechanistic rationale for the observed pathology. The purpose of this study was to identify proteomic differences in hearts of growth-restricted and unrestricted mice, and propose mechanisms related to impairment in adulthood. Friend leukemia virus B (FVB) mouse dams were fed a control (CON: 20% protein), or low-protein (LP: 8% protein) isocaloric diet 2 weeks before mating. LP dams produce 20% less milk, inducing growth restriction. At birth (postnatal; PN1), pups born to dams fed the CON diet were switched to LP dams (PGR group) or a different CON dam. At PN21, a sub-cohort of CON (n = 3 males; n = 3 females) and PGR (n = 3 males; n = 3 females) were euthanized and their proteome analyzed by two-dimensional differential in-gel electrophoresis (2D DIGE) and mass spectroscopy. Western blotting and silver nitrate staining confirmed 2D DIGE results. Littermates (CON: n = 4 males and n = 4 females; PGR: n = 4 males and n = 4 females) were weaned to the CON diet. At PN77, echocardiography measured cardiac function. At PN80, hearts were removed for western blotting to determine if differences persisted into adulthood. 2D DIGE and western blot confirmation indicated PGR had reductions in p57kip2, Titin (Ttn), and Collagen (Col). At PN77, PGR had impaired cardiac function as measured by echocardiography. At PN80, western blots of p57kip2 showed protein abundance recovered from PN21. PN80 silver staining of large molecular weight proteins (Ttn and Col) was reduced in PGR. PGR reduces cell cycle activity at PN21, which is recovered in adulthood. However, collagen fiber networks are altered into adulthood.

Late-gestation protein restriction negatively impacts muscle growth and glucose regulation in steer progeny

The objective of this study was to determine whether the amount of protein provided to cows during late gestation would affect postnatal growth and lead to changes in glucose and insulin concentrations. At 129 d of gestation, 10 mature multiparous Angus cows were stratified by body weight (BW) and body condition score (BCS) and allotted to either low protein level (LP, 6% crude protein [CP]) or high protein level (HP, 12% CP) groups. After calving, cows were managed together on improved pastures, which provided forage in excess of requirements until weaning. Male calves were maintained as a group after weaning on native range until 23 mo of age when individual steers were placed in single pens and fed a finishing diet for 84 d. The 12th rib fat thickness and longissimus muscle area were measured during finishing phase by ultrasound. Twenty days before the end of the finishing phase, steers were subjected to an intravenous glucose tolerance test. Steers were harvested and carcass characteristics collected. Cows' BW and BCS were similar at the initiation of treatment. During treatment HP dams gained 21 kg, whereas LP dams lost 7 kg (P = 0.04). Protein nutrition during late gestation did not influence calf birth weight, BW at weaning, adjusted 205 d BW, or average daily gain during lactation (P > 0.10). Longissimus muscle area measure by ultrasound was greater (P = 0.02) in HP steers at the beginning and end of finishing phase. Fat thickness of the 12th rib was not different (P > 0.10) between treatments. Glucose concentration after intravenous administration decreased (P = 0.002) in LP compared with HP steers. Peak of serum insulin concentration was greater (P = 0.04) and serum insulin concentration tended to decrease (P = 0.08) more rapidly in LP compared with HP steers after glucose infusion. At harvest, hot carcass weight was similar between treatments, but dressing percentage was increased (P = 0.05) in HP compared with LP steers. These data demonstrate that a lower protein nutrition level of dams during late gestation affect carcass characteristics and alter glucose regulation enhancing insulin secretion in steer progeny.

Maternal low-protein diet during lactation combined with early overfeeding impair male offspring's long-term glucose homeostasis.

The early-life nutritional environment affects long-term glucose homeostasis, we investigated the effects of maternal low-protein diet combined with postnatal early overfeeding on the male offspring's glucose homeostasis in adulthood. Only male rats were used, and their delivery was considered postnatal-day 0 (PN0). Wistar rats' dams were divided into control (NP) or low-protein diet (LP). LP dams remained on the diet until PN14, after which all animals were supplied with the control diet. At PN2, litters were adjusted to 9 (control-NL) or 3 (postnatal-overfeeding-PO) pups, resulting in four experimental groups: NP-NL, NP-PO, LP-NL, and LP-PO. Litters were weaned on PN21. At PN80, a batch of animals from all experimental groups underwent surgery for cannula implantation, followed by intravenous glucose tolerance test (ivGTT), but the insulinogenic index (ISI) was calculated. At PN81, animals were euthanized and tissues were collected. LP-diet and early postnatal-overfeeding were effective in promoting the expected biometric outcomes at PN21 and PN81, but the LP-PO animals present a biometric profile similar to the control (NP-NL) group. Postnatal-overfeeding increased fasting glycemia in LP-PO animals (p < 0.01). In the ivGTT, postnatal-overfeeding elevated the glycemia (p < 0.0001), exacerbated in LP-PO animals (p < 0.0001). Insulinemia was reduced by both, maternal LP-diet and postnatal-overfeeding, with a higher degree of reduction in LP-PO animals (p < 0.0001). Maternal LP-diet and postnatal-overfeeding reduced the ISI (p < 0.0001). Factors interaction lead the LP-PO to a lower ISI compared to all other groups (p < 0.0001). The combination of low-protein diet in breastfeeding dams with postnatal overfeeding disturbed the offspring's glucose metabolism in adulthood.

Effect of protein restriction of bovine dams during late gestation on offspring postnatal growth, glucose-insulin metabolism and IGF-1 concentration

The objective of this study was determine whether the amount of protein provided to cows during late gestation would affect postnatal growth and lead to changes on glucose, insulin and insulin-like growth factor concentrations. At 134 d prepartum, 68 multiparous Angus cows were blocked by BW and expected calving date and randomly assigned to low protein level (LP, 6% CP) or high protein level (HP, 12% CP) and were allotted in 12 pens per treatment. At calving, cows were managed together on improved pastures until weaning. Calves were weighed and body measurements were recorded at birth. Blood samples were taken at birth and each 30 d until weaning at 180 d of age. Body weight at birth on HP progeny tended to be great than LP progeny (P = 0.06). At birth, calves from LP dams had greater head circumference (P 〈 0.01), heart girth (P = 0.01) and cannon bone circumference (P = 0.02). However, head circumference /birth BW ratio (P = 0.04), heart girth /birth BW ratio (P = 0.01), body length /birth BW ratio (P = 0.05) and height /birth BW ratio (P = 0.01) was greater on LP calves. Body mass index was greater in HP calves (P = 0.04). No differences were found on BW of calves at weaning, adjusted 205d BW and ADG during lactation (P 〉 0.10). Glucose concentrations were greater on LP calves than HP calves from birth to weaning (81.0 ± 1.5 vs. 76.4 ± 1.2 mg/dl; P 〈 0.001) without any change in insulin concentrations during preweaning growth (LP = 1.61 ± 0.04 ng/ml; HP = 1.61 ± 0.04 ng/ml; P 〉 0.10). Insulin-like growth factor concentrations was less on LP calves at birth (P 〈 0.05) and similar to HP calves during postnatal growth (P 〉 0.10). These data demonstrate that low protein during late gestation in bovine dams may affect fetal growth with proportional increasing of head circumference and low body mass index. Level of protein compromised glucose regulation in early life and affected the IGF-I concentration of newborn calves.

Maternal voluntary physical activity attenuates delayed neurodevelopment in malnourished rats.

What is the central question of this study? In the present study, a reproducible model of maternal voluntary physical activity was developed to evaluate the adaptive response of physical activity by attenuating the effects of maternal undernutrition on physical features, reflex ontogeny and growth trajectory of offspring during development. What is the main finding and its importance? Maternal physical activity may induce neuronal maturation of sensorimotor connections impacting on the patterns of locomotor activity in malnourished offspring. Thus, physical activity should be considered as a therapeutic means of countering the effects of maternal undernutrition, by providing a useful strategy for enhancing the neuronal activity of children born to mothers who experience a restricted diet during pregnancy. This study evaluated the effects of maternal voluntary physical activity during pregnancy and lactation on somatic growth (SG), reflex ontogeny (RO) and locomotor activity (LA) of rats whose mothers were protein restricted. Virgin female Wistar rats were divided into the following six groups: control, normal protein (C-NP, n=4); control, low protein (C-LP, n=4); inactive, normal protein (I-NP, n=8); inactive, low protein (I-LP, n=7); very active, normal protein (VA-NP, n=8); and very active, low protein (VA-LP, n=6). Voluntary physical activity was recorded daily in dams. The LP groups were fed an 8% casein diet, whereas control groups were fed a 17% casein diet during pregnancy and lactation. Offspring were evaluated in terms of SG (body weight and length, latero-lateral skull axis and anteroposterior head axis) and RO (palmar grasp, righting, free-fall righting, negative geotaxis, cliff avoidance, auditory startle response and vibrissa placing). The LA was evaluated at 23, 45 and 60days old in the open field. Voluntary physical activity was reduced during pregnancy and lactation independent of the maternal diet. Pups from LP dams showed delayed SG, reflex maturation and patterns of LA when compared with control pups. The C-LP and I-LP pups showed a delayed SG, RO and LA. Pups from VA-LP mothers showed no delay in SG and RO and presented a faster development of patterns of LA. Maternal voluntary physical activity attenuated the effects of LP diet on indicators of neurodevelopment and patterns of LA of offspring.

L-Citrulline Supplementation Enhances Fetal Growth and Protein Synthesis in Rats with Intrauterine Growth Restriction

Background: Intrauterine growth restriction (IUGR) results from either maternal undernutrition or impaired placental blood flow, exposing offspring to increased perinatal mortality and a higher risk of metabolic syndrome and cardiovascular disease during adulthood. L-Citrulline is a precursor of L-arginine and nitric oxide (NO), which regulates placental blood flow. Moreover, L-citrulline stimulates protein synthesis in other models of undernutrition.Objective: The aim of the study was to determine whether L-citrulline supplementation would enhance fetal growth in a model of IUGR induced by maternal dietary protein restriction.Methods: Pregnant rats were fed either a control (20% protein) or a low-protein (LP; 4% protein) diet. LP dams were randomly allocated to drink tap water either as such or supplemented with L-citrulline (2 g · kg−1 · d−1), an isonitrogenous amount of L-arginine, or nonessential L-amino acids (NEAAs). On day 21 of gestation, dams received a 2-h infusion of L-[1-13C]-valine until fetuses were extracted by cesarean delivery. Isotope enrichments were measured in free amino acids and fetal muscle, liver, and placenta protein by GC–mass spectrometry.Results: Fetal weight was ∼29% lower in the LP group (3.82 ± 0.06 g) than in the control group (5.41 ± 0.10 g) (P < 0.001). Regardless of supplementation, fetal weight remained below that of control fetuses. Yet, compared with the LP group, L-citrulline and L-arginine equally increased fetal weight to 4.15 ± 0.08 g (P < 0.05) and 4.13 ± 0.1 g (P < 0.05 compared with LP), respectively, whereas NEAA did not (4.05 ± 0.05 g; P = 0.07). Fetal muscle protein fractional synthesis rate was 35% lower in the LP fetuses (41% ± 11%/d) than in the control (61% ± 13%/d) fetuses (P < 0.001) and was normalized by L-citrulline (56% ± 4%/d; P < 0.05 compared with LP, NS compared with control) and not by other supplements. Urinary nitrite and nitrate excretion was lower in the LP group (6.4 ± 0.8 μmol/d) than in the control group (17.9 ± 1.1 μmol/d; P < 0.001) and increased in response to L-citrulline or L-arginine (12.1 ± 2.2 and 10.6 ± 0.9 μmol/d; P < 0.05), whereas they did not in the LP + NEAA group.Conclusion: L-Citrulline increases fetal growth in a model of IUGR, and the effect may be mediated by enhanced fetal muscle protein synthesis and/or increased NO production.

Gestational protein restriction alters cell proliferation in rat placenta.

We recently showed that gestational protein restriction (GPR) alters the structure of the rat placenta on day 19 of gestation (dG). The aim of the study was to investigate the spatial and temporal immunolocalization of proliferating cell antigen Ki67 in normal and GPR placental development. Pregnant Wistar rats were divided into two groups: normal (NP, 17 % casein) or low-protein diet (LP, 6 % casein). Placentas and fetus were collected and weighed at 15, 17, 19 and 21 dG. Morphological, morphometric and ultrastructural analyses were performed. Immunoperoxidase was used to identify nuclear antigen Ki67 in placental sections. We observed a significant reduction in the number of trophoblast giant cells and glycogen cells in the LP group. Placental weight was significantly reduced only at 17 dG in the LP group, in parallel to a decrease in glycogen cells. From 15 to 21 dG, the thickness of the junctional zone (JZ) decreased in NP and LP animals, while that of the labyrinth zone (LZ) increased in parallel to a reduction in the number of proliferating cells in this LZ zone. GPR significantly inhibits cell proliferation in the JZ, especially at 15 and 17 dG. The ultrastructural appearance of the cytoplasm of giant and cytotrophoblastic cells indicates degeneration from 15 to 21 dG and this effect is enhanced in LP animals suggesting early aging. Offspring of NP dams were significantly heavier than offspring of LP dams at 21 dG. GPR causes modifications in specific regions of the placenta, cell proliferation inhibition and fetal growth restriction.

Induction of autophagy through the activating transcription factor 4 (ATF4)-dependent amino acid response pathway in maternal skeletal muscle may function as the molecular memory in response to gestational protein restriction to alert offspring to maternal nutrition.

The aim of the present study was to investigate the mechanistic basis of protein deficiency during pregnancy in mother that is transduced to offspring. To this end, timed-pregnant Sprague-Dawley rats were fed either a control (20 % of energy from protein) or low-protein (LP, 8 % of energy from protein) diet during gestation. Tissues were collected after delivery from rat dams, and skeletal muscle was collected at postnatal day 38 from the offspring. Quantitative RT-PCR and Western blot analyses were performed to determine mRNA and protein levels. Histological analysis was performed to evaluate myofibre size. LP dams gained significantly less weight during pregnancy, developed muscle atrophy, and had significantly lower circulating threonine and histidine levels than control dams. The mRNA expression of the well-known amino acid response (AAR) pathway-related target genes was increased only in the skeletal muscle of LP dams, as well as the protein expression levels of activating transcription factor 4 (ATF4) and phosphorylated eukaryotic translation initiation factor 2α (p-eIF2α). The mRNA expression of autophagy-related genes was significantly increased in the skeletal muscle of LP dams. Moreover, the mRNA expression of genes involved in both AAR and autophagy pathways remained elevated and was memorised in the muscle of LP offspring that consumed a post-weaning control diet. Additionally, the LP diet increased an autophagy marker, microtubule-associated proteins 1A/1B light chain 3B (LC3B) protein expression in the skeletal muscle of rat dams, consistent with the initiation of autophagy. The LP diet further increased ATF4 binding at the predicted regions of AAR and autophagy pathway-related genes. Increased binding of ATF4 unveils the crucial role of ATF4 in the activation of autophagy in response to protein restriction. Our data suggest that molecular changes in maternal muscle are memorised in the offspring long after gestational protein restriction, reinforcing the role of maternal signalling in programming offspring health.

Low protein diet during gestation and lactation induces autophagy‐related gene LC3 in the liver of rat dams (737.5)

Autophagy is essential for the maintenance of cellular homeostasis and is activated in mouse liver cells by amino acid deprivation. A low protein diet during gestation and lactation has been associated with poor fetal development but consequence in mother has not been fully investigated. This study aims to investigate the effects of a low protein diet during gestation and lactation on liver physiology of dams and characterize the associated hepatic autophagy. Timed‐pregnant Sprague‐Dawley rats were fed a control (control, 20 kcal% protein) or a low protein (LP, 8 kcal% protein) diet during gestation and lactation. Dam liver was collected for analysis at weaning. LP dams had significantly lower circulating threonine than control dams, which is accompanied with the hepatic activation of Amino Acid Response pathway. Expression of an autophagy‐related gene, microtubule‐associated protein 1 light chain 3 beta (lc3) was up‐regulated by the LP diet which coincided with increased ATF4 binding at the predicted promoter region of lc3 gene. Also, we observed increased LC3 protein localization outside nucleus by the LP diet. Knocking down of ATF4 by siRNA decreased mRNA and protein expressions of LC3 in a rat hepatoma cell line. In conclusion, our data demonstrate that ATF4 is potentially involved in the autophagy process through regulation of LC3 by a low protein diet during gestation and lactation in the liver of rat dam.

Effects of pre‐ and postnatal diets on body compositions of diet‐induced obesity prone Sprague‐Dawley rats

Increasing numbers of studies have shown that growth retardation due to malnutrition during the fetal growth period followed by postnatal catch‐up growth results in obesity. To determine whether a prenatal low‐protein diet followed by postnatal high‐fat diet increase offspring's propensity to obesity, we fed obese‐prone Sprague‐Dawley females a diet containing 10% fat and either 8% (LP) or 20% (NP) protein for 3 wk prior to breeding and through pregnancy and lactation. At weaning, male offspring were placed on a 20% protein diet containing either 10% (NF) or 45% (HF) fat, thus, giving 4 groups (LP‐NF, NP‐NF, LP‐HF, NP‐HF). Results indicated that birth weights of offspring born of LP or NP fed dams were not different. However, at weaning, body weights of offspring born of NP diet fed dams were 2‐fold greater than that of LP fed dams. After 12 weeks of postnatal NF or HF diet, offspring of LP dams compared to that of NP dams had greater rates of body weight increase (fold‐increase, 11.0 vs. 6.3). Similarly, the rate increases in adipose tissue (23.4 vs. 12.6) and lean body (12.9 vs. 7.7) mass were greater in the offspring of LP dams compared to offspring of NP dams. In both LP and NP groups, postnatal NF and HF diets had no effects on body weight, adipose tissue and lean mass. These data suggest that low protein intake during pregnancy and lactation predisposes offspring to greater rates for body weight, adipose tissue and lean mass increase.

Effects of protein restriction in utero on the metabolism of mink dams (&amp;lt;i&amp;gt;Neovison vison&amp;lt;/i&amp;gt;) and on mink kit survival as well as on postnatal growth

Protein restriction in utero may give rise to restricted growth as well as induce metabolically related diseases. In order to determine the suitability of mink as an animal model for metabolism studies, the effects of protein restriction during gestation on dam and kit performance must first be determined. Mink dams were fed an adequate protein (AP; crude protein:fat:carbohydrate ratio of 31:55:14% of metabolizable energy, ME) or a low protein diet (LP; 19%:49%: 32% of ME) during the last 21.2 ± 3.3 days of gestation, followed by an adequate diet during lactation. Respiration and balance experiments were performed during late gestation and twice during lactation. The dietary treatment only affected energy metabolism traits significantly during the treatment period in late gestation, such that LP dams oxidized less protein (12% vs 23% of heat production, HE, P = 0.001) but more carbohydrate (37% vs 26% of HE, P -0.75.day-1, P < 0.05) than AP dams. Reproductive performance and kit organ growth were not affected by diet. Kit losses up to weaning were higher in LP than AP dams (2.0 vs 1.4, P < 0.05). LP fetuses weighed less (8.3 vs 11.6 g, P < 0.001) and were shorter (6.2 vs 7.6 cm, P < 0.001) than AP fetuses, however, differences might have been due to different implantation times. LP kits weighed 8.5% less than AP kits at birth, and remained lighter until 21 days of age. The LP diet caused growth restriction and increased kit mortality indicating that the dietary protein supply during late gestation was suboptimal to re-quirements. The long-term consequences of protein restriction in utero in terms of permanent metabolic changes in adulthood now need to be investigated.

Maternal fructose consumption programs gene expression pattern in intestine of male offspring

Metabolic programming of insulin‐sensitive processes by maternal diet has been demonstrated for liver, pancreas, and muscle of offspring, but has not been evaluated for small intestine. To determine the effects of maternal (MAT) and postweaning diet (PWT) on intestinal programming, male offspring of Sprague Dawley females fed either a 60% starch diet (CON), 60% fructose diet (FRU) or protein restricted diet (LP) throughout pregnancy and lactation were weaned to either a CON, FRU or a 30% fat diet (FAT). Intestinal mRNA expression was evaluated at 18 weeks for all nine MAT×PWT groups. Glucose 6 phosphatase (G6Pase) was elevated in FRUFAT compared with FRUCON offspring (3.98 ± 0.70 vs. 1.16 ± 0.53, P &lt; 0.05) with a similar tendency for PEP carboxykinase (PCK1) (2.95 ± 0.62 vs. 1.53 ± 0.47, P=0.07). G6Pase and PCK1 mRNA levels in offspring from CON and LP dams were not affected by the FAT diet (G6Pase: CONFAT vs. CONCON, 0.46 ± 0.50 vs. 1.17 ± 0.64, LPFAT vs. LPCON, 0.84 ± 0.56 vs. 1.92 ± 0.56, PCK1: CONFAT vs. CONCON, 0.57 ± 0.44 vs. 1.33 ± 0.53, LPFAT vs. LPCON, 0.95 ± 0.53 vs. 0.82 ± 0.53). Collectively, offspring from FRU dams had more (P &lt; 0.05) PCG‐1α mRNA compared with offspring of CON or LP dams (1.31 ± 0.14 vs. 0.89 ± 0.13 or 0.85 ± 0.14, respectively). These data indicate a persistent adaptive response for intestinal gene expression in offspring that is sensitive to maternal fructose consumption and amplified with postweaning fat intake.Grant Funding Source: NIH DK077581

Dietary protein concentration correlates in a complex way with glucose metabolism and growth performance in pregnant rats

We studied the influence of dietary protein concentration (PC) on the adaptation mechanism of maternal glucose metabolism to gestation, and on maternal body weight (BW) gain using pregnant rats fed 4% (low protein, LP), 10% (medium protein, MP) or 20% (high protein, HP) dietary protein concentration. Feed (FI), energy (EI) and protein (PI) intakes were recorded. Plasma glucose, insulin and GH were determined, and insulin:glucose (insulin resistance) and insulin:GH ratios computed. Correlation and regression analyses were used to determine the physiological relationships between metabolic and ponderal variables. MP dams with greater FI and EI (12%), and lower PI (44%) than HP dams showed similar maternal and fetal growth performance because of the maintained energy efficiency (EE). LP dams, with similar FI and EI, and lower PI (81%) than HP dams, failed to catch up due to the low EE. PC exerted a non-linear influence on BW gain, insulin and GH, through EI and EE modifications. The EI linearly influenced hormone concentrations with the maximum and minimum hormone response in MP and LP dams, respectively. Insulin resistance increased as PC decreased, whereas the GH lipolytic effect appeared to predominate over insulin action. Circulating hormones and metabolites affected nutrient partitioning between dam and fetus, with the result that the competing demands for materno-fetal growth of HP and MP dams, but not the LP dams, were satisfied. A deeper knowledge of the nature of the materno-fetal energy relationships will enhance the manipulation of the growth performance of the fetus in several animal species.

Differential effects of protein malnutrition in pregnant rats on the expression of placental prolactin-like proteins

Summary This study evaluated the effect of chronic protein deficiency during pregnancy on the synthesis of placental lactogen (PL) and prolactin-like proteins (PLPs). Pregnant rats were pair-fed isocaloric diets containing 20% (C) or 5% casein (low protein, LP). In LP animals, maternal weight gain was significantly decreased by 82%, fetal body weight by 20% and placental weight by 30%. These data confirm that this low protein adequate calorie diet results in significant feto-placental growth retardation. Maternal plasma levels of growth hormone (GH), insulin-like growth factor 1 (IGF-1) and thyroid stimulating hormone (TSH) did not significantly differ between C and LP dams, whereas IGF-1 in maternal kidney tissue was significantly higher in LP than in C animals. Placental tissue explants cultured in the presence of [ 35 S]-labeled methionine showed that total secretion of de novo synthesized protein did not differ between C and LP explants. Analysis of secreted proteins by polyacrylamide gel electrophoresis and Western immunoblot procedures revealed that the level of PLP-B immunoreactive protein was significantly decreased by 45% in media from LP placentae, whereas no significant alterations were seen in PLP-C, PL-II or GHRP-1 levels. Northern blot analysis showed a 48% decrease in placental PLP-B steady state mRNA levels in LP animals. Thus, data indicate that a low protein, adequate calorie diet during pregnancy is associated with a selective decrease in PLP-B expression relative to other major secreted placental proteins during late gestation. Evidence further suggests a distinct role for PLP-B in feto-placental growth in this model for intrauterine growth retardation.

Effects of malnutrition on cell genesis and migration in developing brain in rats

Rats were fed a diet containing either 5% (LP) or 25% (HP) casein throughout gestation. The animals, delivered by a cesarean section on the 21st day of gestation, were given a pulse of [ 3H]thymidine and killed 2 h later. No differences were observed in the mitotic index, but the labeling index of the ventricular zone cells of the lateral ventricle was higher in the case of litters of the LP dams. This we atribute to a disproportionate increase of the S phase in relation to the cell cycle in malnutrition. To study the effects of malnutrition on the programming of cell genesis, the dams were given [ 3H]thymidine on the 20th day of gestation, and the litters were killed on the 21st postnatal day. The labeled neurons reached the second layer of the cerebral cortex in both groups, indicating that the programming was not affected by gestational malnutrition. Postnatal undernutrition was induced by doubling the litter size. The cell generation cycle was prolonged in the undernourished animals. Not all phases, however, were evenly affected: S was prolonged, G 2 was not affected, but G 1 was shortened. The external granular layer maintained its proliferative activity in the undernourished animals beyond the stage it had ceased in the controls. The migration of the cerebellar granule neurons was slow. It is proposed that tardiness in the migration of the neurons may interfere with synaptogenesis.