Effect of maternal low protein diet during pregnancy on the fetal liver of rats

Ultrastructural organization of the liver of rat pups in early postnatal ontogenesis when pregnant and lactating rats are kept on a low-protein diet

Protein deficiency in the diet during pregnancy and lactation has a serious impact on the offspring by programming a predisposition to such serious diseases as hypertension and type 2 diabetes mellitus. In our study, we examined liver ultrastructure of rat pups at ages 2, 21, and 40 days with maternal protein deficiency. Body weight of the pups progressively lagged behind the control throughout the experiment, and the timing of eye opening indicated a slowdown of development. In the liver of 2-day-old animals, the proportion of hematopoietic cells at early stages of differentiation was higher as compared to the control. At the ultrastructural level, no obvious pathological changes were revealed, but a decrease in the amount of organelles was observed simultaneously with accumulation of lipids and glycogen. In the course of the experiment, a progressive decrease in the amount of the rough endoplasmic reticulum and ribosomes and increasing accumulation of glycogen in the cytoplasm of hepatocytes were noted. The most pronounced difference in ultrastructure between periportal and pericentral hepatocytes of control rat pups was detected on the 40th day of development, whereas in the low-protein diet group, the difference was weakly pronounced throughout the experiment. Thus, we showed that with prenatal and early postnatal protein deficiency, the growth and development of rat pups slows down, and glycogen accumulates excessively in the liver concurrently with a decrease in the amount of organelles.

Impact of Ionizing Radiation Exposure on Placental Function and Implications for Fetal Programming

Accidental exposure to high-dose radiation while pregnant has shown significant negative effects on the developing fetus. One fetal organ which has been studied is the placenta. The placenta performs all essential functions for fetal development, including nutrition, respiration, waste excretion, endocrine communication, and immunological functions. Improper placental development can lead to complications during pregnancy, as well as the occurrence of intrauterine growth-restricted (IUGR) offspring. IUGR is one of the leading indicators of fetal programming, classified as an improper uterine environment leading to the predisposition of diseases within the offspring. With numerous studies examining fetal programming, there remains a significant gap in understanding the placenta's role in irradiation-induced fetal programming. This review aims to synthesize current knowledge on how irradiation affects placental function to guide future research directions. This review provides a comprehensive overview of placental biology, including its development, structure, and function, and summarizes the placenta's role in fetal programming, with a focus on the impact of radiation on placental biology. Taken together, this review demonstrates that fetal radiation exposure causes placental degradation and immune function dysregulation. Given the placenta's crucial role in fetal development, understanding its impact on irradiation-induced IUGR is essential.

Prenatal prednisone exposure impacts liver development and function in fetal mice and its characteristics

Prednisone, a widely used glucocorticoid drug in human and veterinary medicine, has been reported to cause developmental toxicity. However, systematic studies about the effect of prednisone on fetal liver development are still unclear. We investigated the potential effects of maternal exposure to clinically equivalent doses of prednisone during different gestational stages on cell proliferation and apoptosis, cell differentiation, glucose and lipid metabolism, and hematopoiesis in the liver of fetal mice, and explored the potential mechanisms. Results showed that prenatal prednisone exposure (PPE) could suppress cell proliferation, inhibit hepatocyte differentiation, and promote cholangiocyte differentiation in the fetal liver. Meanwhile, PPE could result in the enhancement of glyconeogenesis and bile acid synthesis and the inhibition of fatty acid β-oxidation and hematopoiesis in the fetal liver. Further analysis found that PPE-induced alterations in liver development had obvious stage and sex differences. Overall, the alteration in fetal liver development and function induced by PPE was most pronounced during the whole pregnancy (GD0-18), and the males were relatively more affected than the females. Additionally, fetal hepatic insulin-like growth factor 1 (IGF1) signaling pathway was inhibited by PPE. In conclusion, PPE could impact fetal liver development and multiple functions, and these alterations might be partially related to the inhibition of IGF1 signaling pathway.

Low Protein Programming Causes Increased Mitochondrial Fusion and Decreased Oxygen Consumption in the Hepatocytes of Female Rats

The liver is one of the major organs involved in the regulation of glucose and lipid homeostasis. The effectiveness of metabolic activity in hepatocytes is determined by the quality and quantity of its mitochondria. Mitochondrial function is complex, and they act via various dynamic networks, which rapidly adapt to changes in the cellular milieu. Our present study aims to investigate the effects of low protein programming on the structure and function of mitochondria in the hepatocytes of adult females. Pregnant rats were fed with a control or isocaloric low-protein diet from gestational day 4 until delivery. A normal laboratory chow was given to all dams after delivery and to pups after weaning. The rats were euthanized at 4 months of age and the livers were collected from female offspring for investigating the mitochondrial structure, mtDNA copy number, mRNA, and proteins expression of genes associated with mitochondrial function. Primary hepatocytes were isolated and used for the analysis of the mitochondrial bioenergetics profiles. The mitochondrial ultrastructure showed that the in utero low-protein diet exposure led to increased mitochondrial fusion. Accordingly, there was an increase in the mRNA and protein levels of the mitochondrial fusion gene Opa1 and mitochondrial biogenesis genes Pgc1a and Essra, but Fis1, a fission gene, was downregulated. Low protein programming also impaired the mitochondrial function of the hepatocytes with a decrease in basal respiration ATP-linked respiration and proton leak. In summary, the present study suggests that the hepatic mitochondrial dysfunction induced by an in utero low protein diet might be a potential mechanism linking glucose intolerance and insulin resistance in adult offspring.

Protein Requirements of Oncorhynchus mykiss Cultured in the Convection-Water Cages by Evaluating Growth, Body Composition and Liver Health

The diet formulation for trout has changed dramatically over the last decade due to changes in the ingredient markets and advances in feed processing technology. The protein requirements of Oncorhynchus mykiss were established at the end of the last century, and it is unclear whether these requirements are applicable to modern dietary formulations. Therefore, an eight-week feeding trial was performed to measure the protein requirements of O. mykiss by evaluating growth, body composition, antioxidation property, innate immune response and liver morphology. The five experimental diets were prepared to contain the same levels of crude lipid (120 g/kg) and graded levels of crude protein (356.3, 383.9, 411.5, 439.2 and 466.8 g/kg). The results suggested that the growth, feed utilization and whole-body crude protein levels were significantly increased when fish were fed diets containing 439.2 and 466.8 g/kg crude protein. Meanwhile, low dietary protein levels (356.3 and 383.9 g/kg) significantly down-regulated the mRNA levels of insulin-like growth factor I, catalase, glutathione peroxidase, superoxide dismutase, complement 3 and lysozyme, and also up-regulated the insulin-like growth factor binding protein 1 as well as proinflammatory cytokine expression in the liver, including interleukin 1β, interleukin 8 and tumor necrosis factor-α. Moreover, low dietary protein levels (356.3 and 383.9 g/kg) damaged liver structure, suppressed total antioxidative capacity and increased the malondialdehyde content in liver. In conclusion, high dietary protein (439.2 and 466.8 g/kg) promoted fish growth, while low dietary protein (356.3 and 383.9 g/kg) damaged liver structure, induced oxidative stress and inflammatory responses and weakened non-specific immunity. The protein requirement of O. mykiss reared in the convection-water cages is no less than 439.2 g/kg for optimal growth, antioxidant and immune properties.

Effects of maternal branched-chain amino acid and alanine supplementation on growth and biomarkers of protein metabolism in dams fed a low-protein diet and their offspring

A considerable number of studies have reported that maternal protein restriction may disturb fetal growth and organ development due to a lower availability of amino acids. Leucine, one of branched-chain amino acid (BCAA) promotes protein synthesis through mechanistic target of rapamycin signaling. Here, we investigated the effects of BCAA supplementation in the dams fed a low-protein diet on serum and hepatic biochemical parameters of protein metabolism of dams and their offspring. Female ICR mice were fed a control (20% casein), a low-protein (10% casein), a low-protein with 2% BCAAs or a low-protein with 2% alanine diet for 2 weeks before mating and then throughout pregnancy and lactation. Alanine was used as an amino nitrogen control for the BCAA. Dams and their male offspring were sacrificed at postnatal day 21. There were no changes in body weight and fat mass in low-protein fed dams; however, BCAA supplementation significantly increased fat mass and serum leptin levels. Low-protein diet consumption reduced maternal protein synthesis based on biochemical analysis of serum albumin and hepatic protein levels and immunoblotting of S6 protein, which were increased by BCAA and alanine supplementation. Offspring from dams fed a low-protein diet exhibited lower body and organ weights. Body weight and hepatic protein levels of the offspring were increased by alanine supplementation. However, the decreased serum biochemical parameters, including glucose, triglyceride, total protein and albumin levels in the low-protein offspring group were not changed in response to BCAA or alanine supplementation. A reduced density of the hepatic vessel system in the offspring from dams fed a low-protein diet was restored in the offspring from dams fed either BCAA and alanine-supplemented diet. These results suggest that supplementation of amino nitrogen per se may be responsible for inducing hepatic protein synthesis in the dams fed a low-protein diet and alleviating the distorted growth and liver development of their offspring.

Maternal low protein diet and fetal programming of lean type 2 diabetes

Maternal nutrition is found to be the key factor that determines fetal health in utero and metabolic health during adulthood. Metabolic diseases have been primarily attributed to impaired maternal nutrition during pregnancy, and impaired nutrition has been an immense issue across the globe. In recent years, type 2 diabetes (T2D) has reached epidemic proportion and is a severe public health problem in many countries. Although plenty of research has already been conducted to tackle T2D which is associated with obesity, little is known regarding the etiology and pathophysiology of lean T2D, a variant of T2D. Recent studies have focused on the effects of epigenetic variation on the contribution of in utero origins of lean T2D, although other mechanisms might also contribute to the pathology. Observational studies in humans and experiments in animals strongly suggest an association between maternal low protein diet and lean T2D phenotype. In addition, clear sex-specific disease prevalence was observed in different studies. Consequently, more research is essential for the understanding of the etiology and pathophysiology of lean T2D, which might help to develop better disease prevention and treatment strategies. This review examines the role of protein insufficiency in the maternal diet as the central driver of the developmental programming of lean T2D.

Maternal Protein Restriction and Post-Weaning High-Fat Feeding Alter Plasma Amino Acid Profiles and Hepatic Gene Expression in Mice Offspring

Maternal undernutrition during pregnancy is closely associated with epigenetic changes in the child, and it affects the development of obesity throughout the child’s life. Here, we investigate the effect of fetal low protein exposure and post-weaning high-fat consumption on plasma amino acid profiles and hepatic gene expression. Mother C57BL/6J mice were fed a 20% (CN) or 9% (LP) casein diet during pregnancy. After birth, the male offspring of both these groups were fed a high-fat diet (HF) from 6 to 32 weeks. At 32 weeks, the final body weight between the two groups remained unchanged, but the LP-HF group showed markedly higher white fat weight and plasma leptin levels. The LP-HF group exhibited a significant increase in the concentrations of isoleucine, leucine, histidine, phenylalanine, serine, and tyrosine. However, no differences were observed in the lipid content in the liver. According to the hepatic gene expression analysis, the LP-HF group significantly upregulated genes involved in the chromatin modification/organization pathways. Thus, maternal low protein and a post-weaning high-fat environment contributed to severe obesity states and changes in gene expression related to hepatic chromatin modification in offspring. These findings provide novel insights for the prevention of lifestyle-related diseases at the early life stage.

The First United Arab Emirates National Representative Birth Cohort Study: Study Protocol

BACKGROUND

In recent years, the prevalence of non-communicable diseases (NCDs) has escalated. Evidence suggests that there are strong associations between nutrition in early life and the risk of disease in adulthood. This manuscript describes the study protocol of the First United Arab Emirates National Representative Birth Cohort Study (UAE-BCS), with the objective of investigating nutrition and lifestyle factors in the first 1,000 days of life. The main aims of the study are (1) to address critical issues relating to mother and child nutrition and their effect on growth and development, (2) to profile maternal nutrition, child growth, health, and development outcomes in early life, and (3) to study the associations between these factors among the Emirati population in the UAE.

METHODS/DESIGN

In this study, a multidisciplinary team of researchers was established including credible researchers from the UAE, Lebanon, Australia, and the United Kingdom to launch the First United Arab Emirates 3-year birth cohort study. We aim to recruit 260 pregnant Emirati women within their first trimester, which is defined by the study as from 8 to 12 weeks pregnant, from obstetrics and gynecology clinics in the UAE. Participants will be recruited via face-to-face interviews and will receive a total of 11 visits with 1 visit in each trimester of pregnancy and 8 visits after delivery. Maternal data collection includes, socio-demographic and lifestyle factors, dietary intake, anthropometric measurements, physical activity, maternal psychological state, and blood samples for biochemical analysis. Post-partum, visits will take place when the child is 0.5, 4, 6, 9, 12, 18, and 24 months old, with data collection including infant anthropometric measurements, young child feeding practices, dietary intake, supplement use and the eating environment at home, as well as all maternal data collection described above, apart from blood samples. Additional data collection for the child includes early child developmental assessments taking place at three timepoints: (1) within 2 weeks of birth, (2) at 10-14 months and (3) at 22-26 months of age. Early child developmental assessments for the infant include vision, hearing, cognition, motor skills, social-emotional reactivity, neurodevelopmental, and sleep assessments.

DISCUSSION

The United Arab Emirates Birth Cohort study protocol provides a standardized model of data collection methods for collaboration among the multisectoral teams within the United Arab Emirates to enrich the quality and research efficiency in early nutrition, thereby enhancing the health of mothers, infants, and children.

Protein restriction during puberty alters nutritional parameters and affects ovarian and uterine histomorphometry in adulthood in rats

In a large part of the population inefficient ingestion of proteins, whether for cultural, aesthetic or economic reasons, is a global concern. Low-protein diets can cause severe functional complications, mainly during the development and maturation of organs and systems, including the female reproductive system. The present study investigated the effect of nutritional protein restriction during puberty on the oestrous cycle and expression of sex steroid receptors (AR, ERα e ERβ) in ovarian and uterine tissues of adult rats. Protein restriction promoted lower body weight gain, feed efficiency and higher caloric intake. There was an increase in the oestrus phase arrest without changing the total length of the oestrous cycle. The consumption of low-protein diet also reduced the thickness of the uterine endometrium (uterine epithelium and endometrial stroma) in addition to increasing the number of primary and atretic follicles in the ovaries. Furthermore, the low-protein diet reduced the levels of androgen receptor (AR) and increased the oestrogen receptor β (ERβ) in the ovary, while no significant changes were observed in the uterus. Our study reinforces the importance of adequate protein intake during puberty, since physiological changes in this developmental period interfere with the histomorphometry of the ovaries and uteri, possibly resulting in impaired folliculogenesis and fertility in the reproductive period.

Prenatal dexamethasone exposure caused fetal rats liver dysplasia by inhibiting autophagy-mediated cell proliferation

As a synthetic glucocorticoid, dexamethasone has been widely used in the clinical treatment of premature birth and related pregnant diseases, but its clinical use is still controversial due to developmental toxicity. This study aimed to confirm the proliferation inhibitory effect of pregnant dexamethasone exposure (PDE) on fetal liver development and elucidate its molecular mechanism. In vitro studies, we found that dexamethasone inhibited hepatocyte proliferation through autophagy activated by glucocorticoid receptor (GR)-forkhead protein O1 (FOXO1) pathway. Subsequently, in vivo, we confirmed in a PDE rat model that male fetal liver proliferation was inhibited, and the expression of the GR-FOXO1 pathway and autophagy were increased. Taken together, PDE induces autophagy by activating the GR-FOXO1 pathway, which leads to fetal liver proliferation inhibition and dysplasia in offspring rats. This study confirmed that dexamethasone activates cell autophagy in utero through the GR-FOXO1 pathway, thereby inhibiting hepatocyte proliferation and liver development, which provides theoretical basis for understanding the developmental toxicity of dexamethasone and guiding the rational clinical use.

Defective liver glycogen autophagy related to hyperinsulinemia in intrauterine growth-restricted newborn wistar rats

Maternal malnutrition plays a critical role in the developmental programming of later metabolic diseases susceptibility in the offspring, such as obesity and type 2 diabetes. Because the liver is the major organ that produces and supplies blood glucose, we aimed at defining the potential role of liver glycogen autophagy in the programming of glucose metabolism disturbances. To this end, newborns were obtained from pregnant Wistar rats fed ad libitum with a standard diet or 65% food-restricted during the last week of gestation. We found that newborns from undernourished mothers showed markedly high basal insulin levels whereas those of glucagon were decreased. This unbalance led to activation of the mTORC1 pathway and inhibition of hepatic autophagy compromising the adequate handling of glycogen in the very early hours of extrauterine life. Restoration of autophagy with rapamycin but not with glucagon, indicated no defect in autophagy machinery per se, but in signals triggered by glucagon. Taken together, these results support the notion that hyperinsulinemia is an important mechanism by which mobilization of liver glycogen by autophagy is defective in food-restricted animals. This early alteration in the hormonal control of liver glycogen autophagy may influence the risk of developing metabolic diseases later in life.

Hyperphosphorylation of fetal liver IGFBP-1 precedes slowing of fetal growth in nutrient-restricted baboons and may be a mechanism underlying IUGR

In cultured fetal liver cells, insulin-like growth factor (IGF) binding protein (IGFBP)-1 hyperphosphorylation in response to hypoxia and amino acid deprivation is mediated by inhibition of mechanistic target of rapamycin (mTOR) and activation of amino acid response (AAR) signaling and casein kinase (CK)2. We hypothesized that fetal liver mTOR inhibition, activation of AAR and CK2, and IGFBP-1 hyperphosphorylation occur before development of intrauterine growth restriction (IUGR). Pregnant baboons were fed a control (C) or a maternal nutrient restriction (MNR; 70% calories of control) diet starting at gestational day (GD) 30 (term GD 185). Umbilical blood and fetal liver tissue were obtained at GD 120 (C, n = 7; MNR, n = 10) and 165 (C, n = 7; MNR, n = 8). Fetal weights were unchanged at GD 120 but decreased at GD 165 in the MNR group (-13%, P = 0.03). IGFBP-1 phosphorylation, as determined by parallel reaction monitoring mass spectrometry (PRM-MS), immunohistochemistry, and/or Western blot, was enhanced in MNR fetal liver and umbilical plasma at GD 120 and 165. IGF-I receptor autophosphorylation^Tyr1135 (-64%, P = 0.05) was reduced in MNR fetal liver at GD 120. Furthermore, fetal liver CK2 (α/α'/β) expression, CK2β colocalization, proximity with IGFBP-1, and CK2 autophosphorylation^Tyr182 were greater at GD 120 and 165 in MNR vs. C. Additionally, mTOR complex (mTORC)1 (p-P70S6K^Thr389, -52%, P = 0.05) and mTORC2 (p-Akt^Ser473, -56%, P < 0.001) activity were decreased and AAR was activated (p-GCN2^Thr898, +117%, P = 0.02; p-eIF2α^Ser51, +294%, P = 0.002; p-ERK^Thr202, +111%, P = 0.03) in MNR liver at GD 120. Our data suggest that fetal liver IGFBP-1 hyperphosphorylation, mediated by mTOR inhibition and both AAR and CK2 activation, is a key link between restricted nutrient and oxygen availability and the development of IUGR.

Effect of low- and high-protein maternal diets during gestation on reproductive outcomes in the rat: a systematic review and meta-analysis

Studies with animal models have consistently demonstrated adverse health outcomes in offspring born following nutritional manipulation during gestation. However, the effects of gestational dietary protein modification on reproductive outcomes at birth are less clear. We, therefore, conducted a systematic review and meta-analysis of controlled trials to determine whether high- or low-protein diets are associated with altered reproductive outcomes in a commonly studied species, the rat. Included studies were identified through a systematic search using electronic databases and manual literature review to identify randomized studies published between June 1972 and March 2019. Thirty-two studies were identified and used to analyze the effects of low- and high-protein gestational diets on litter size, litter weight, gestational weight gain, and gestational feed intake. The results indicate that low-protein diets significantly reduced litter weight (P < 0.00001) and gestational weight gain (P < 0.0006), but did not influence litter size (P = 0.62) or gestational feed intake (P = 0.25). In contrast, high-protein diets were found to reduce gestational feed intake (P = 0.004) but did not influence litter size (P = 0.56), litter weight (P = 0.22), or gestational weight gain (P = 0.35). The results suggest that low but not high-protein gestational diets alter reproductive outcomes at birth in rats.

Hitting a triple in the non-alcoholic fatty liver disease field: sucrose intake in adulthood increases fat content in the female but not in the male rat offspring of dams fed a gestational low-protein diet

The excessive consumption of carbohydrates is related to non-alcoholic fatty liver disease (NAFLD) in infants and adults. The effect of combining maternal malnutrition and a high carbohydrate intake on the development of NAFLD in adulthood remains unknown. We therefore hypothesized that consumption of 5% sucrose by the offspring of dams fed a low-protein diet during pregnancy promotes liver fat accumulation and oxidative damage differently in females and males. To test this, 12-month-old female and male offspring of mothers fed a Control (C) or low-protein diet (Restricted, R) were provided with either tap water or 5% sucrose for a period of 10 weeks. Livers were excised to measure the fat content and 3-nitrotyrosine (3-NTyr) immunostaining; serum samples were also obtained to measure the concentration of malondialdehyde (MDA). Data were analyzed using a non-repeated measures three-way analysis of variance to determine significant differences (P<0.05) regarding to the interaction among maternal diet, sucrose consumption and sex. Results showed that the liver fat content of females from R mothers was higher than that of their male counterpart. Hepatic 3-NTyr immunostaining and serum MDA concentrations were not affected by the interaction involving maternal diet, sucrose consumption and sex. Otherwise, liver fat content was correlated with the hepatic 3-NTyr immunostaining and serum MDA concentrations only in females. Thus, sucrose intake in adulthood increases fat content in the female but not in the male rat offspring of dams fed with a low-protein diet during pregnancy. This research emphasizes the importance of a balanced diet during pregnancy and the influence of the diet on the adult offspring.

Study protocol: Mother and Infant Nutritional Assessment (MINA) cohort study in Qatar and Lebanon

Background

The Middle East and North Africa region harbors significant proportions of stunting and wasting coupled with surging rates of non-communicable diseases (NCDs). Recent evidence identified nutrition during the first 1000 days of life as a common denominator not only for optimal growth but also for curbing the risk of NCDs later in life. The main objective of this manuscript is to describe the protocol of the first cohort in the region to investigate the association of nutrition imbalances early in life with birth outcomes, growth patterns, as well as early determinants of non-communicable diseases. More specifically the cohort aims to1) examine the effects of maternal and early child nutrition and lifestyle characteristics on birth outcomes and growth patterns and 2) develop evidence-based nutrition and lifestyle guidelines for pregnant women and young children.

Methods/design

A multidisciplinary team of researchers was established from governmental and private academic and health sectors in Lebanon and Qatar to launch the Mother and Infant Nutritional Assessment 3-year cohort study. Pregnant women (n = 250 from Beirut, n = 250 from Doha) in their first trimester are recruited from healthcare centers in Beirut, Lebanon and Doha, Qatar. Participants are interviewed three times during pregnancy (once every trimester) and seven times at and after delivery (when the child is 4, 6, 9, 12, 18, and 24 months old). Delivery and birth data is obtained from hospital records. Data collection includes maternal socio-demographic and lifestyle characteristics, dietary intake, anthropometric measurements, and household food security data. For biochemical assessment of various indicators of nutritional status, a blood sample is obtained from women during their first trimester. Breastfeeding and complementary feeding practices, dietary intake, as well as anthropometric measurements of children are also examined. The Delphi technique will be used for the development of the nutrition and lifestyle guidelines.

Discussion

The Mother and Infant Nutritional Assessment study protocol provides a model for collaborations between countries of different socio-economic levels within the same region to improve research efficiency in the field of early nutrition thus potentially leading to healthier pregnancies, mothers, infants, and children.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0864-5) contains supplementary material, which is available to authorized users.

Effect of maternal protein restriction on liver metabolism in rat offspring

Consequences of gestational protein restriction (GPR) on liver metabolism in rat offspring were investigated. Pregnant dams were divided into groups: normal (NP, 17% casein) or low-protein diet (LP, 6% casein). Livers were collected from 30-day-old offspring (d30) for analysis or isolation of mitochondria. At d30, hepatic and muscle glycogen was increased in LP group. Mitochondrial swelling and oxygen uptake (recorded with a Clark-type electrode) were significantly reduced in NP female and LP pups. Thiobarbituric acid reactive substances production was lower in females (NP or LP), suggesting significant inhibition of lipid peroxidation. Measurement of mitochondrial respiration (states 3 and 4 stimulated by succinate) showed a higher ADP/O ratio in LP pups, particularly females, suggesting higher phosphorylation efficiency. In the 1st month of life, under our experimental conditions, GPR protects liver mitochondria against oxidative stress and females seem to be more resistant or more suitable for survival.

Effect of maternal chronic intermittent hypoxia during gestation on offspring growth in the rat

OBJECTIVE

Obstructive sleep apnea, a breathing disorder caused by the repetitive collapse of the upper airway during sleep, results in a state of chronic intermittent hypoxia (CIH). Although the etiology and consequences of CIH are extensively investigated in the adult, the developmental ramifications of this disease process are unknown.

DESIGN

This study was done to investigate the effect of CIH during gestation on offspring development. Pregnant female Spraque-Dawley rats were exposed to daily CIH throughout the gestational period.

RESULTS

Postnatal day-1 offspring from CIH mothers were asymmetrically growth restricted, with decreased body weights and elevated brain-weight:liver-weight ratios. Furthermore, CIH newborns had elevated heart- and brain-weight:body weight ratios, and decreased liver-weight:body weight ratios. By adulthood, body weights of growth restricted offspring were significantly greater, as were the liver-weight:body weight ratios. CIH offspring also had greater body fat deposition, were hyperglycemic and had elevated plasma levels of insulin during development into adults.

CONCLUSION

These data suggest that alteration of the maternal intrauterine environment by gestational CIH effects the long-term development of the offspring and increases the risk of the offspring to metabolic diseases in adulthood.