Adult Male Rat Offspring Research Articles

Perinatal bisphenol A exposure has an age- and dose-dependent association with thyroid allostasis adaptive response, as well as anxiogenic-depressive-like and asocial behaviors in juvenile and adult male rats

Thyroid hormones are essential for brain development, and a shortage throughout the fetal and postnatal periods can result in mood disorders. Perinatal exposure to bisphenol A (BPA) affects thyroid activity and dependent processes indirectly during pregnancy or early postnatal life. This is particularly important because it may cause changes in tissue ontogeny, increasing the risk of developing disorders later in life. The study aimed to investigate the consequences of thyroid hormone deficiency on anxiety, social, and depressive behaviors, as well as disruption in thyroid peroxidase (TPO) gene expression, which influences the NF-κB/Nrf-2/HO-1/iNOS signaling pathway, leading to oxidative stress, inflammation, and DNA fragmentation in perinatal BPA exposure (PND18), and whether these effects can be observed in juvenile (PND60) and adult (PND95) male offspring rats. BPA increased anxiety-like behavior while decreasing sucrose preference and sociability on a choice task between novel conspecific male rats and enhanced immobility on the forced swim test. Perinatal exposure to BPA causes thyroid insult by overproducing ROS, increasing iNOS, and NF-κB levels—these effects, in turn, down-regulate Nrf-2/HO-1 signaling, resulting in DNA fragmentation within thyroid tissues. Furthermore, perinatal BPA exposure for 60 and 95 days resulted in a significant fold decrease in TPO mRNA levels in the thyroid tissues, with an insignificant fold rise in TPO expression levels in BPA 50–60. In conclusion, the present study found that perinatal BPA exposure induced thyroid allostasis-adaptive response by inhibiting the NF-κB/Nrf-2/HO-1/iNOS signaling pathway and altering the transcriptional expression of TPO, where TSH reinforced a possible association with TPO activity, disrupting thyroid hormone synthesis in juvenile rats and gradual deterioration reaching the adult stage.

Detrimental effect of prenatal progesterone exposure on anxiety and depressive-like responses in adult male and female rat offspring: role of plasma, hippocampal corticosterone and hippocampal progesterone receptors

In clinical practice, the use of exogenous progesterone (Pro) is often required in assisted reproduction programs due to reduced levels of the hormone and the risk of miscarriage. Exposure to the hormone reduces anxiety in rodents, but the long-term effects of prenatal exposure in adult offspring are unknown. Therefore, the present study was designed to investigate the effect of prenatal Pro treatment on anxiety- and depression-like behavior and the effect on plasma, hippocampal corticosterone (CORT) and hippocampal progesterone receptor (PR) in young adult male and female rat offspring. The behavioral responses of offspring of both sexes were tested in the open field, and the elevated plus maze tests, and for depressive-like behavior in the sucrose preference test, the forced swimming test and the splash test. CORT levels and PR expression were measured by ELISA. The results indicate that prenatal Pro exposure at low and high doses (10 and 50 mg/kg, s.c. during G0-G10) induces anxiogenic and depressive-like effects compared to vehicle-treated controls, which are associated with high plasma and hippocampal CORT levels and upregulated hippocampal PR in male and female adult offspring. Our results demonstrate that prenatal Pro exposure has detrimental effects on the emotional status of male and female adult offspring, which may be associated with long-term changes in hormonal homeostasis.

Maternal cafeteria diet programs fecal microbiota and modulates serum fatty acid and amino acid levels in adulthood rats

Maternal food environment can program fecal microbiota in offspring mediated by the imprint of intrauterine conditions. Gut bacteria play a role in host fatty acid and amino acid metabolism. This study aimed to determine the effects of maternal diet on fecal microbiota, and the impact on fatty acid and amino acid metabolism in male offspring rats. Ten male pups from dams fed standard diet (C-C, n = 5) and cafeteria diet (Caf-C, n = 5) were fed standard chow diet for twenty-three weeks. Fresh fecal samples were collected at three and twenty-six weeks of age for fecal microbiota analysis by metagenomic sequencing of the V3-V4 region of the 16S rRNA gene. At the end of the study, serum samples were collected to analyse fatty acids from phospholipid and cholesterol ester fractions by gas chromatography and free amino acids by liquid chromatography. The bacterial abundance from the Actinobacteria and Proteobacteria phyla significantly decreased over time for both groups. Additionally, significant differences were found between C-C and Caf-C groups in these bacterial phyla. In the Caf-C group, Firmicutes and Elusimicrobia phyla increased, while Bacteroidetes decreases in adulthood samples. At the genus level, the abundance of Bacteroides decreased, while Elusimicrobium, Lactobacillus, Turicibacter, Blautia, and Veillonella increased in the Caf-C group. Several metabolites including PL-MCFAs (caprylic acid and capric acid), CE-MUFAs (palmitoleic acid and heptadecenoic acid), and free amino acids aspartate, glutamic acid, and cysteine were significantly higher in Caf-C group. This study underscores the putative programming of offspring fecal microbiota by maternal diet impact. These changes led to alterations fatty acids and amino acids metabolism in adult male offspring rats.

The effects of moderate prenatal alcohol exposure on performance in hippocampal-sensitive spatial memory and anxiety tasks by adult male and female rat offspring

Moderate prenatal alcohol exposure (mPAE) results in structural alterations to the hippocampus. Previous studies have reported impairments in hippocampal-sensitive tasks, but have not compared performance between male and female animals. In the present study, performance in hippocampal-sensitive spatial memory and anxiety behavior tests were compared across adult male and female saccharin (SACC) control mPAE Long-Evans rat offspring. Two tests of spatial memory were conducted that were aimed at assessing memory for recently acquired spatial information: A delayed spatial alternation task using an M-shaped maze and a delayed match-to-place task in the Morris water task. In both tasks, rats in SACC and mPAE groups showed similar learning and retention of a spatial location even after a 2-h interval between encoding and retention. A separate group of adult male and female SACC and mPAE rat offspring were tested for anxiety-like behaviors in the elevated plus-maze paradigm. In this test, both male and female mPAE rats exhibited a significantly greater amount of time and a greater number of head dips in the open arms, while locomotion and open arm entries did not differ between groups. The results suggest that mPAE produces a reduction in anxiety-like behaviors in both male and female rats in the elevated plus-maze.

Lactoferrin Supplementation during Pregnancy and Lactation Protects Adult Male Rat Offspring from Hypertension Induced by Maternal Adenine Diet.

Lactoferrin, a glycoprotein derived from breastmilk, is recognized for its health benefits in infants and children; however, its protective effects when administered during gestation and lactation against offspring hypertension remain unclear. This study aimed to investigate whether maternal lactoferrin supplementation could prevent hypertension in offspring born to mothers with chronic kidney disease (CKD), with a focus on nitric oxide (NO), renin-angiotensin system (RAS) regulation, and alterations in gut microbiota and short-chain fatty acids (SCFAs). Prior to pregnancy, female rats were subjected to a 0.5% adenine diet for 3 weeks to induce CKD. During pregnancy and lactation, pregnant rats received one of four diets: normal chow, 0.5% adenine diet, 10% lactoferrin diet, or adenine diet supplemented with lactoferrin. Male offspring were euthanized at 12 weeks of age (n = 8 per group). Supplementation with lactoferrin during gestation and lactation prevented hypertension in adult offspring induced by a maternal adenine diet. The maternal adenine diet caused a decrease in the index of NO availability, which was restored by 67% with maternal LF supplementation. Additionally, LF was related to the regulation of the RAS, as evidenced by a reduced renal expression of renin and the angiotensin II type 1 receptor. Combined maternal adenine and LF diets altered beta diversity, shifted the offspring's gut microbiota, decreased propionate levels, and reduced the renal expression of SCFA receptors. The beneficial effects of lactoferrin are likely mediated through enhanced NO availability, rebalancing the RAS, and alterations in gut microbiota composition and SCFAs. Our findings suggest that maternal lactoferrin supplementation improves hypertension in offspring in a model of adenine-induced CKD, bringing us closer to potentially translating lactoferrin supplementation clinically for children born to mothers with CKD.

Gestationally administered RAS modulators reprogram endotoxic cardiovascular and inflammatory profiles in adult male offspring of preeclamptic rats.

Previous studies showed that preeclampsia (PE) amplifies cardiovascular dysfunction induced by endotoxemia in adult male, but not female, offspring. Here, we asked if such aggravated endotoxic insult could be nullified by modulators of the renin-angiotensin system (RAS). PE was induced by gestational administration of Nω-nitro-L-arginine methyl ester(L-NAME, a nitric oxide synthase inhibitor). Adult male offspring of PE mothers treated gestationally with angiotensin 1-7 (Ang1-7, angiotensin II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (peroxisome proliferator-activated receptor gamma, PPARγ, agonist), or combined losartan/pioglitazone were instrumented with femoral indwelling catheters and challenged intravenously with a 5-mg/kg dose of lipopolysaccharides (LPS, 5mg/kg). LPS caused significant decreases in blood pressure (BP) and spectral index of overall heart rate variability and increases in heart rate and left ventricular contractility (dP/dtmax). These effects were mostly reduced to similar magnitudes by individual drug therapies. In offspring born to Ang1-7-treated dams, the spectral index of cardiac sympathovagal balance showed elevated sympathetic dominance in response to LPS. Immunohistochemistry revealed that Ang1-7, but not losartan/pioglitazone, abolished the exaggerated increases in toll-like receptor 4 (TLR-4) expression caused by PE/LPS in heart tissues and neuronal circuits of brainstem rostral ventrolateral medulla (RVLM). By contrast, the losartan/pioglitazone regimen, but not Ang1-7, decreased and increased angiotensin converting enzyme (ACE) and ACE2 expression, respectively. Together, gestational fetal reprogramming of Ang II (depression) and Ang1-7 (activation) arms of RAS effectively counterbalance worsened endotoxic cardiovascular and inflammatory profiles in adult male offspring of PE rats.

Effects of Prenatal Dexamethasone Treatment and Post-Weaning Moderate Fructose Intake on Synaptic Plasticity and Behavior in Adult Male Wistar Rat Offspring.

Early-life glucocorticoid overexposure induces diverse neurodevelopmental outcomes regarding stress reactivity and cognition. Increased fructose consumption has also been associated with alterations in cognitive capacity and behavior. The present study investigated the effects of prenatal dexamethasone exposure on synaptic plasticity, locomotion, anxiety, and recognition memory in adult male Wistar rat offspring, and whether these effects are potentiated by postnatal fructose consumption. Pregnant female rats were treated with dexamethasone during late gestation and male offspring were supplemented with a moderate dose of fructose. Recognition memory, locomotion, and anxiety-like behavior were assessed using a novel object recognition test, open-field test, and elevated plus maze, respectively. Hippocampal synaptic plasticity was estimated by the levels of growth-associated protein 43 (GAP-43), synaptophysin, postsynaptic density protein 95, calcium/calmodulin-dependent kinase IIα, and their activating phosphorylations. Additionally, protein levels of the glucocorticoid receptor (GR) and its transcriptionally active phosphorylated form were evaluated. Prenatal dexamethasone treatment induced an anxiolytic-like effect, stimulation of exploratory behavior, and novelty preference associated with an increase in GR and GAP-43 protein levels in the hippocampus. Fructose overconsumption after weaning did not modify the effects of prenatal glucocorticoid exposure. Applied prenatal dexamethasone treatment may induce changes in reactions to novel situations in male Wistar rats.

Maternal protein restriction combined with postnatal sugar consumption alters liver proteomic profile and metabolic pathways in adult male offspring rats

This study investigated the impact of maternal protein restriction (MPR) and early postnatal sugar consumption (SUG) on the liver health of adult male descendant rats. Male offspring of mothers fed a normal protein diet (NPD) or a low protein diet (LPD) were divided into four groups: Control (CTR), Sugar Control (CTR + SUG), LPD during gestation and lactation (GLLP), and LPD with sugar (GLLP + SUG). Sugar consumption (10% glucose diluted in water) began after weaning on day 21 (PND 21), and at 90 days (PND 90), rats were sacrificed for analysis. Sugar intake reduced food intake and increased water consumption in CTR + SUG and GLLP + SUG compared to CTR and GLLP. GLLP and GLLP + SUG groups showed lower body weight and total and retroperitoneal fat compared to CTR and CTR + SUG. CTR + SUG and GLLP + SUG groups exhibited hepatocyte vacuolization associated with increased hepatic glycogen content compared to CTR and GLLP. Hepatic catalase activity increased in GLLP compared to CTR. Proteomic analysis identified 223 differentially expressed proteins (DEPs) among experimental groups. While in the GLLP group, the DEPs enriched molecular pathways related to cellular stress, glycogen metabolic pathways were enriched in the GLLP + SUG and CTR + SUG groups. The association of sugar consumption amplifies the effects of MPR, deregulating molecular mechanisms related to metabolism and the antioxidant system.

Fish oil supplementation during pregnancy decreases liver endocannabinoid system and lipogenic markers in newborn rats exposed to maternal high-fat diet.

Maternal high-fat diet (HF) programs obesity, metabolic dysfunction-associated steatotic liver disease (MASLD), hypertriglyceridemia, and hyperglycemia associated with increased endocannabinoid system (ECS) in the liver of adult male rat offspring. We hypothesized that maternal HF would induce sex specific ECS changes in the liver of newborn rats, prior to obesity onset, and maternal fish oil (FO) supplementation would reprogram the ECS and lipid metabolism markers preventing liver triglycerides (TG) accumulation. Female rats received a control (CT) (10.9% fat) or HF (28.7% fat) diet 8weeks prior to mating and during pregnancy. A subgroup of HF dams received 3% FO supplementation in the HF diet (35.4% fat) during pregnancy (HFFO). Serum hormones and liver TG, ECS, lipid metabolism, oxidative stress and autophagy markers were assessed in male and female newborn offspring. Maternal HF diet increased liver cannabinoid receptor 1 (CB1) in males and decreased CB2 in females, with no effect on liver TG. Maternal FO supplementation reduced liver CB1 regardless of the offspring sex, but reduced TG liver content only in females. FO reduced the liver content of the endocannabinoid anandamide in males, and the content of 2-arachidonoylglycerol in both sexes. Maternal HF increased lipogenic and decreased lipid oxidation markers, and FO induced the opposite regulation in the liver of offspring. Prenatal HF and FO differentially modulate liver ECS in the offspring before obesity and MASLD development. These results suggest that maternal nutrition at critical stages of development can modulate the offspring's ECS, predisposing or preventing the onset of metabolic diseases.

Consumption of sucrose in maternal and postnatal stages leads to kidney affectation in adult male rats

High sugar-sweetened beverage intake has been related to human kidney disease and metabolic alterations. We determine the impact of high sucrose intake from pregnancy until early postnatal days and post-weaning on kidneys from adult male offspring rats. Wistar female rats were mated and assigned into two groups: one control drinking tap water (CM) and another drinking 5 % sucrose diluted in water (SM). Two offspring per mother were randomly allocated into two experimental groups at weaning. One had free access to simple water (CO) and the other to 5 % sucrose (SO) for 14 weeks. After treatment, levels of relative aquaporin-2 (AQP2), glomerulosclerosis index (GI), collecting tube area, perirenal fat, blood creatinine, and blood ureic nitrogen concentration (BUN) were determined. Two-way ANOVA followed by Bonferroni post-hoc test was used, considering P ≤ 0.05 as a significant statistical difference. Sucrose consumption during gestation/lactation and interaction increased AQP2 expression in the renal cortex and BUN concentration. In contrast, gestation/lactation consumption increased collecting tube area, post-weaning consumption favored perirenal fat, and finally, gestation/lactation, post-weaning, and the interaction caused glomerulosclerosis. Our results suggest that the consumption of sucrose water during gestation/lactation or post-weaning or combination triggers pathological changes in the kidneys of adult rats.

Maternal Vitamin D Deficiency Impairs the Development of β Cells in Offspring Rats in a Sex-Dependent Manner.

Recent studies have shown that maternal vitamin D deficiency (VDD) causes long-term metabolic changes in offspring. However, little is known about the impact of maternal VDD on offspring endocrine pancreas development and insulin secretion in the adult life of male and female animals. Female rats (Wistar Hannover) were fed either control (1000 IU Vitamin D3/kg), VDD (0 IU Vitamin D3/kg), or a Ca2+-enriched VDD diet (0 IU Vitamin D3/kg + Ca2+ and P/kg) for 6 weeks and during gestation and lactation. At weaning, VDD status was confirmed based on low serum calcidiol levels in dams and pups. Next, male and female offspring were randomly separated and fed a standard diet for up to 90 days. At this age, serum calcidiol levels were restored to normal levels in all groups, but serum insulin levels were decreased in VDD males without affecting glucagon levels, glycemia, or glucose tolerance. Islets isolated from VDD males showed lower insulin secretion in response to different glucose concentrations, but this effect was not observed in VDD females. Furthermore, VDD males, but not females, showed a smaller total pancreatic islet area and lower β cell mass, an effect that was accompanied by reduced gene expression of Ins1, Ins2, Pdx1, and SLC2A2. The decrease in Pdx1 expression was not related to the methylation profile of the promoter region of this gene. Most of these effects were observed in the male VDD+Ca2+ group, indicating that the effects were not due to alterations in Ca2+ metabolism. These data show that maternal VDD selectively impairs the morphology and function of β cells in adult male offspring rats and that female offspring are fully protected from these deleterious effects.

Sucrose consumption modifies the urethrogenital reflex and histological organization of the bulbospongiosus muscle in the male rat

Disorders of the bulbospongiosus muscle (Bsm) are associated with male sexual dysfunction, such as premature ejaculation. We determined the effect of sucrose-water consumption during pregnancy-lactation and postnatal on reflex responses and morphology of Bsm fibers in adult male Wistar rat offspring. Female rats were mated and grouped into consumed tap water mothers and sucrose-water (5 %) mothers during pregnancy-lactation to obtain experimental groups. Male pups were weaned and assigned into four groups (n = 12; each group). Those from control mothers who continued drinking tap water (CM–CO group) or sucrose water (CM–SO group), and those from sucrose mothers who drank tap water (SM–CO group) or continued drinking sucrose water (SM–SO group) until adult life. In male rat offspring (n = 6 per group) was recorded the electrical activity of Bsm was recorded during penile stimulation and urethrogenital reflex (UGR). Other male rat offspring were designated for histological analysis (n = 6 per group). Sucrose consumption during prenatal stages increased the frequency of the Bsm during UGR, while pre and postnatal consumption modified muscle fiber cross-sectional area and increased the collagen content, suggesting that a combination of a diet with pre- and postnatal sucrose changes the Bsm morphophysiology possibly causing male sexual dysfunctions.

Abstract P202: Changes In Cerebral Mitochondrial Function In Intrauterine Growth-Restricted Offspring Before The Development Of Hypertension And Cerebrovascular Dysfunction

Background: Preeclampsia (PE), new-onset gestational hypertension (HTN) affects 3-8% of all births in the USA. PE is the leading cause for intrauterine growth restriction (IUGR). IUGR children have increased risks of HTN and cerebrovascular disease (CVD) later in life. Prior studies in our lab show adult male IUGR rat offspring (OS) to develop HTN, CVD, and cerebral mitochondrial dysfunction (mtDys) at 17 weeks while female IUGR OS exhibit CVD. The role of mtDys in HTN is unknown and is the focus of our study. We hypothesize that IUGR OS will have mtDys prior to HTN. Methods: Our surgical PE animal model utilized the reduced-uterine-perfusion pressure (RUPP) surgery at GD 14. OS from NP served as controls (CON) while OS from RUPP mothers were IUGR. At 12 weeks, OS BP was measured alongside cerebral mtDys through mitochondrial fusion and fission, electron-transport chain (ETC) proteins, and respiration. Results: BP did not change between sexes or among IUGR and CON offspring. Male IUGR OS showed elevated mtRes (State 2: 199 ± 1.08 v. 76 ± 1.13 pmol/mg, p < .05; State 3: 555 ± 3.02 v. 245 ± 1.77 pmol/mg, p < .05; State 4: 346 ± 1.66 v. 85 ± 1.12 pmol/mg, p < .05). Female IUGR and CON OS had no changes in BP or mtRes. Male IUGR OS had increased mito-fusion proteins MFN-1 (176 ± 1.68 v. 100 ± .57 IU/protein/CON %, p < .05), MFN-2 (155 ± 1.36 v. 100 ± .74 IU/protein/CON %, p < .05) and OPA-1 (166 ± 1.99 v. 100 ± .73 IU/protein/CON %, p < .05). DRP-1 had no changes in males; females had no changes in fusion or fission. Male IUGR OS had changes in ETC proteins (CI: 8 ± 9.34 v. 100 ± .82 IU/protein/CON %, p < .05; CII: 23 ± .53 v. 100 ± .52 IU/protein/CON %, p < .05; CIII: 26 ± .23 v. 100 ± .41 IU/protein/CON %, p < .05), as did female IUGR OS (CI: 12 ± .24 v. 100 ± .86 IU/protein/CON %, p < .05; CII: 29 ± .39 v. 100 ± .61 IU/protein/CON %, p < .05; CIII: 39 ± .56 v. 100 ± .62 IU/protein/CON %, p < .05; CIV: 76 ± .74 v. 100 ± .73 IU/protein/CON %, p < .05) vs. CON OS. Summary: Male IUGR OS have elevated mtRes, changed ETC proteins, and fusion proteins that may lead to mtDys and HTN development. This study is clinically relevant because specific cerebral therapy for mtDys for IUGR OS may prevent HTN and CVD development. Future studies will examine changes in mtDys causing male HTN and protection from HTN in females.

Islet hypoplasia of adult offspring rats caused by intrauterine chronic hypoxia is compensated by up-regulation of INS and PDX-1

ABSTRACT Background: Intrauterine chronic hypoxia (ICH) can lead to pancreatic dysmetabolism in offspring. This study aimed to determine the changes in islet function of offspring through a rat ICH model and detect the factors affecting islet function. Methods: Twenty couples of healthy Sprague – Dawley adult rats were randomly mated, and the pregnant rats were randomly allocated to ICH and normal control (NC) groups. Pregnant rats in the ICH group were placed in a hypoxic chamber with 13% oxygen concentration for hypoxia treatment twice a day for 4 h until delivery at 21 days. NC group is inlet with normal air from beginning to end. After delivery, blood was taken from the heart of pregnant rats for blood gas analysis. The weight of the offspring rats was measured at 12 h after birth and 16 weeks after birth. At 16 weeks, the immunohistochemical results of β-cell total, islet area, insulin (INS), and glucose transporter 2 (GLUT2) proteins were obtained from the islets. The mRNA data of INS and pancreatic and duodenal homeobox 1 (PDX-1) genes were obtained from pancreas. Results: We found the β-cell total, islet area, and the positive cell area of INS and GLUT2 of offspring rats in ICH group were lower than those of NC group, while the levels of INS and PDX-1 genes were higher in ICH group than in NC group. Conclusions: ICH can lead to islet hypoplasia in adult male offspring rats. However, this is within the compensatory range.

Comparisons of stress-related neuronal activation induced by restraint in adult male rat offspring with prenatal exposure to buprenorphine, methadone, or morphine.

Prenatal opioid exposure may impede the development of adaptive responses to environmental stimuli by altering the stress-sensitive brain circuitry located at the paraventricular nucleus of the hypothalamus (PVH) and locus coeruleus (LC). Corticotropin-releasing factor (CRF) released from neurons in the PVH has emerged as a key molecule to initiate and integrate the stress response. Methadone (Meth) and buprenorphine (Bu) are two major types of synthetic opioid agonists for first-line medication-assisted treatment of opioid (e.g., morphine, Mor) use disorder in pregnant women. No studies have compared the detrimental effects of prenatal exposure to Meth versus Bu on the stress response of their offspring upon reaching adulthood. In this study, we aimed to compare stress-related neuronal activation in the PVH and LC induced by restraint (RST) stress in adult male rat offspring with prenatal exposure to the vehicle (Veh), Bu, Meth, or Mor. CFos-immunoreactive cells were used as an indicator for neuronal activation. We found that RST induced less neuronal activation in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. RST-induced neuronal activation was completely prevented by central administration of a CRF receptor antagonist (α-helical CRF9-41, 10 μg/3 μL) in all exposure groups, suggesting the crucial role of CRF in this stress response. In offspring without RST, central administration of CRF (0.5 μg/3 μL)-induced neuronal activation in the PVH and LC. CRF-induced neuronal activation was lessened in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. Moreover, RST- or CRF-induced neuronal activation in the Meth exposure group was comparable with that in the Mor exposure group. Further immunohistochemical analysis revealed that the Meth and Mor exposure groups displayed less CRF neurons in the PVH of offspring with or without RST compared with the Bu or Veh groups. Thus, stress-induced neuronal activation in the PVH and LC was well preserved in adult male rat offspring with prenatal exposure to Bu, but it was substantially lessened in those with prenatal exposure to Meth or Mor. Lowered neuronal activation found in the Meth or Mor exposure groups may be, at least in part, due to the reduction in the density of CRF neurons in the PVH.

Impaired Expression of Mu- and Kappa-Opioid Receptor mRNA in the Midbrain of Rats with Prenatal Alcohol Intoxication

Disruption of normal epigenetic reprogramming during the prenatal period under the influence of exogenous factors affects fetus development and adult phenotype formation. The mechanisms through which determinants, such as maternal alcohol intake, contribute to the formation of an alcohol-vulnerable phenotype later in life still remain unclear. In this paper, we suggest that alteration in the reinforcing properties of ethanol in prenatally alcohol-exposed subjects may be associated with transcriptional dysregulation of the brain opioid receptor genes. We compared voluntary alcohol intake and levels of mRNA coding for μ- (MOP) and κ-opioid (KOP) receptors in the mesolimbic areas of adult male offspring of the female Wistar rats having received 10% ethanol as the only source of liquid throughout pregnancy or water (control). We found that prenatally alcohol exposed rats had higher alcohol preference on PND60 (free-choice paradigm) and lower mRNA expression for both MOP and KOP in the midbrain compared to the control. This suggests a potential link between prenatal alcohol, dysfunction of the brain opiate system and adult vulnerability for alcohol use disorder.

Investigating the Effects of Maternal Separation on Hypothalamic-Pituitary-Adrenal Axis and Glucose Homeostasis under Chronic Social Defeat Stress in Young Adult Male Rat Offspring

Introduction: Given the suggested metabolic regulatory effects of stress-responsive genes and based on the impacts of early-life stress on HPA axis development, this study aimed to characterize the maternal separation (MS) impact on the communication between glucose metabolism and HPA axis dysregulations under chronic social defeat stress (CSDS). Methods: During the first 2 weeks of life, male Wistar rats were either exposed to MS or left undisturbed with their mothers (Std). Starting on postnatal day 50, the animals of each group were either left undisturbed in the standard group housing (Con) or underwent CSDS for 3 weeks. There were four groups (n = 10/group): Std-Con, MS-Con, Std-CSDS, and MS-CSDS. Results: Early and/or adult life adversity reduced β-cell number, muscular FK506-binding protein 51 (FKBP51) content, and BMI in adulthood. The reduction of β-cell number and BMI in the MS-CSDS rats were more profound than MS-Con group. CSDS either alone or in combination with MS reduced locomotor activity and increased and decreased corticotropin-releasing factor type 1 receptor (CRFR1) content, respectively, in hypothalamus and pancreas. Although, under CSDS, MS intensified HPA axis overactivity and reduced isolated islets’ insulin secretion, it could promote resilience to depression symptoms. No differences were observed in hypothalamic Fkbp5 gene DNA methylation and glucose tolerance among groups. Conclusion: MS exacerbated HPA axis overactivity and the endocrine pancreas dysfunctions under CSDS. The intensified corticosterone secretion and the diminished content of pancreatic CRFR1 protein could be involved in the reduced β-cell number and islets’ insulin secretion under CSDS. The decreased muscular FKBP51 content might be a homeostatic response to slow down insulin resistance development under chronic stress.

Perinatal exposure to isocaloric diet with moderate-fat promotes pancreatic islets insulin hypersecretion and susceptibility to islets exhaustion in response to fructose intake in adult male rat offspring

AimsPerinatal maternal hypercaloric diets increase the susceptibility to metabolic disorders in the offspring. We hypothesized that maternal intake of an isocaloric moderate-fat diet (mMFD) would disturb the glucose homeostasis and favor the β-cell failure in response to fructose overload in adult male offspring. MethodsFemale Wistar rats received an isocaloric diet (3.9 kcal/g) containing 29 % (mMFD) or 9 % as fat (mSTD) prior mating and throughout gestation and lactation. After weaning, male offspring received standard chow and fructose-drinking water (15 %) between 120 and 150 days old. Key findingsmMFD offspring had higher body weight, visceral adiposity and, fasting glycemia, with normal insulinemia. Fructose increased glycemia at 15 min from oral glucose administration, but only mMFD had returned to basal glucose levels at 120 min. Fructose increased HOMA-IR index regardless diet, but only mMFD exhibited hyperinsulinemia and a higher HOMA-β index. mMFD pancreatic islets showed increased area and insulin immunostaining density, suggesting β-cell hypertrophy. Fructose induced the expected compensatory hypertrophy in mSTD islets, while the opposite occurred in mMFD islets, associated with reduced insulin immunostaining, suggesting lower insulin storage. Pancreatic islets isolated from mMFD offspring exhibited higher glucose-stimulated insulin release at physiological concentrations. However, at higher glucose concentrations, the islets from fructose-treated mMFD reduced dramatically their insulin release, suggesting exhaustion. SignificanceIsocaloric mMFD induced adaptive mechanism in the offspring allowing insulin hypersecretion, but under metabolic challenge with fructose, β-cell compensation shifts to exhaustion, favoring dysfunction. Therefore, a maternal MFD may contribute to developing diabetes under fructose overload in the adult offspring.

Maternal stress induced endoplasmic reticulum stress and impaired pancreatic islets’ insulin secretion via glucocorticoid receptor upregulation in adult male rat offspring

Exposure to perinatal (prenatal and/or postnatal) stress is considered as a risk factor for metabolic disorders in later life. Accordingly, this study aimed to investigate the perinatal stress effects on the pancreatic endoplasmic reticulum (ER) stress induction, insulin secretion impairment and WFS1 (wolframin ER transmembrane Glycoprotein, which is involved in ER homeostasis and insulin secretion) expression changes, in rat offspring. According to the dams’ period of exposure to variable stress, their male offspring were divided into, control (CTRL); pre-pregnancy, pregnancy, lactation stress (PPPLS); pre-pregnancy stress (PPS); pregnancy stress (PS); lactation stress (LS); pre-pregnancy, pregnancy stress (PPPS); pregnancy, lactation stress (PLS); pre-pregnancy, lactation stress (PPLS) groups. Offspring pancreases were removed for ER extraction and the assessment of ER stress biomarkers, WFS1 gene DNA methylation, and isolated islets’ insulin secretion. Glucose tolerance was also tested. In the stressed groups, maternal stress significantly increased plasma corticosterone levels. In PPS, PS, and PPPS groups, maternal stress increased Bip (Hsp70; heat shock protein family A member 4), Chop (Ddit3; DNA- damage inducible transcript3), and WFS1 protein levels in pancreatic extracted ER. Moreover, the islets’ insulin secretion and content along with glucose tolerance were impaired in these groups. In PPS, PS, LS and PPPS groups, the pancreatic glucocorticoid receptor (GR) expression increased. Maternal stress did not affect pancreatic WFS1 DNA methylation. Thus, maternal stress, during prenatal period, impaired the islets’ insulin secretion and glucose homeostasis in adult male offspring, possibly through the induction of ER stress and GR expression in the pancreas, in this regard the role of WFS1 protein alteration in pancreatic ER should also be considered.

Low protein diet during lactation programs hepatic metabolism in adult male and female rats

The liver is an essential regulator of energy metabolism, and its function can be disrupted by nutritional alterations. Since liver development continues during breastfeeding nutritional challenges during this period predispose patients to diseases throughout life. A maternal protein-restricted (PR) diet during lactation promotes reductions in the body weight, adiposity, and plasma glucose and insulin, leptin resistance and an increase in corticosterone and catecholamines in adult male rat offspring. Here, we investigated hepatic metabolism in the offspring (both sexes) of PR (8% protein diet during lactation) and control (23% protein diet) dams. Both male and female offspring were evaluated at 6 months of age. PR males had no liver steatosis and manifested a reduction in lipids in hepatocytes adjacent to the vasculature. These animals had lower levels of esterified cholesterol in hepatocytes, suggesting higher biliary excretion, unchanged glycolysis and gluconeogenesis, and lower contents of the markers of mitochondrial redox balance and endoplasmic reticulum (ER) stress response and estrogen receptor alpha. PR females showed normal hepatic morphology associated with higher uptake of cholesterol esters, normal glycolysis and gluconeogenesis, and lower ER stress parameters without changes in the key markers of the redox balance. Additionally, these animals had lower content of estrogen receptor alpha and higher content of androgen receptor. The maternal PR diet during lactation did not program hepatic lipid accumulation in the adult progeny. However, several repair homeostasis pathways were altered in males and females, possibly compromising maintenance of normal liver function.