Rat Strains Research Articles

The Effect of Giving Soursop Fruit Juice (Annona muricata, L.) on Hemoglobin Levels in Wistar Bunting Strain Rats Exposed to Cigarette Smoke

Background: Anemia in pregnancy can be caused by exposure to cigarette. A large number of free radicals can cause the number of erythrocytes to decrease. It takes a component to neutralize free radicals, namely antioxidants obtained from various fruits. Soursop contains sources of antioxidants such as flavonoid compounds, polyphenols, and vitamin C. Researchers want to know whether soursop juice can be used as an alternative antioxidant to prevent the decrease in hemoglobin levels of pregnant women. Objective: To determine the effect of giving soursop juice on hemoglobin levels of pregnant white rats with exposure to cigarette smoke. Methods: The experimental laboratory research was designed using the Randomized Post Test Only Control Group Design method. The experimental animal samples were 20 pregnant female Wistar (Rattus norvegicus) rats composed of two control and three treatment groups. Rats were given soursop fruit juice from the first day of rearing until the 18th day of gestation and exposed to cigarette smoke from the 6th day until the 18th. Then blood samples were taken from the mother's heart to measure the hemoglobin level. Results: The results of the hemoglobin level test showed that there was difference between the treatment group and control group. There is an increasing trend from the postitive control group to treatment group. Conclusion: Giving soursop fruit juice can prevent the decrease in hemoglobin levels of pregnant rats exposed to cigarette smoke. Keywords: anemia, free radicals, antioxidants, vitamin C.

Effect of Ashitaba Extract on Cholesterol in Wistar Rats Given a High-Fat Diet and Computational Lethal Dose Test

High cholesterol levels in the blood can cause various health problems, namely atherosclerosis, stroke, coronary heart disease, and hypertension. One drug option for someone with hypercholesterolemia is simvastatin. Apart from using simvastatin, you can consume medicinal plants. A medicinal plant that can help reduce high cholesterol levels is Ashitaba (Angelica keiskei) leaf extract. One of the ingredients in Ashitaba extract is xanthoangelol E, Ashitaba chalcones, which can reduce cholesterol synthesis. The aim of this research was to determine the effect of ashitaba (Angelica keiskei) extract on the cholesterol levels of Wistar rats (Rattus novergiccus) given a high-fat diet. In this study, a computational lethal dose test was also carried out. The population in this study was male white rats of the Wistar strain with 30 samples taken. Analysis of this research data uses the One Way Anova statistical test. The results of the study showed that giving ashitaba extract 150mg/kg BW, 300mg/kg BW, and 600mg/kg BW had no effect on the cholesterol levels of Wistar rats given a high-fat diet. This is proven by the results of the Anova test which obtained a significance value of 0.761 > 0.05. Research regarding the toxic effects of ashitaba extract needs to be carried out for further research.

Evaluation of Antidiabetic Activity of Abutilon crispum on Normal and Streptozotocin-induced Diabetic Albino Wistar Rats

Background Diabetes mellitus is a disorder that affects the majority of individuals in the world. Objectives The objective of the current study is to estimate the antidiabetic effect of methanol extract of Abutilon crispum entire plant, which is broadly cultivated in India’s arid and desert areas. This current investigation aims to estimate the efficacy of methanol extract of A. crispum to prevent streptozotocin-induced diabetes mellitus in Albino Wistar strain rats. Materials and Methods In the current examination, methanol extract of the whole plant of A. crispum with doses of 250 and 500 mg/kg/b.wt (body weight) is administered through the oral route to the streptozotocin-prompted diabetic animals where n = 6. We evaluated the differences in food and water intake, body weight levels, fasting glucose, and oral glucose tolerance test (OGTT). When methanol extract of A. crispum was used to evaluate the OGTT for diabetic animals, levels of glucose were found to be pointedly lower when administered with 500 mg/kg b.wt as this is compared to the control group. A. crispum had specifically declined the levels of glucose elevated in diabetic rats. A. crispum is a vital alternative source for managing blood glucose levels in diabetes mellitus that have increased during the condition and need to be further reduced by oral medications that cause hypoglycemia. Biochemical parameters were estimated as a part of the investigation. Results The results demonstrated that the dried methanol extract of A. crispum (250 mg/kg/bwt and 500 mg/kg/bwt) considerably declined those levels of blood glucose during the treatment period when compared to glibenclamide (10 mg/kg), enhanced the metabolism, improved the health of animals and enhanced the OGTT. Conclusion As a result, we can conclude that the whole plant of A. crispum methanol extract contains antidiabetic effects, as well as, hypoglycemic activities.

Effect of Short-Term Restraint Stress on the Expression of Genes Associated with the Response to Oxidative Stress in the Hypothalamus of Hypertensive ISIAH and Normotensive WAG Rats

Normotensive and hypertensive organisms respond differently to stress factors; however, the features of the central molecular genetic mechanisms underlying the reaction of the hypertensive organism to stress have not been fully established. In this study, we examined the transcriptome profiles of the hypothalamus of hypertensive ISIAH rats, modeling a stress-sensitive form of arterial hypertension, and normotensive WAG rats at rest and after exposure to a single short-term restraint stress. It was shown that oxidative phosphorylation is the most significantly enriched process among metabolic changes in the hypothalamus of rats of both strains when exposed to a single short-term restraint stress. The analysis revealed DEGs representing both a common response to oxidative stress for both rat strains and a strain-specific response to oxidative stress for hypertensive ISIAH rats. Among the genes of the common response to oxidative stress, the most significant changes in the transcription level were observed in Nos1, Ppargc1a, Abcc1, Srxn1, Cryab, Hspb1, and Fosl1, among which Abcc1 and Nos1 are associated with hypertension, and Fosl1 and Ppargc1a encode transcription factors. The response to oxidative stress specific to hypertensive rats is associated with the activation of the Fos gene. The DEG’s promoter region enrichment analysis allowed us to hypothesize that the response to oxidative stress may be mediated by the participation of the transcription factor CREB1 (Cyclic AMP-responsive element-binding protein 1) and the glucocorticoid receptor (NR3C1) under restraint stress in the hypothalamus of both rat strains. The results of the study revealed common and strain-specific features in the molecular mechanisms associated with oxidative phosphorylation and oxidative stress response in the hypothalamus of hypertensive ISIAH and normotensive WAG rats following a single short-term restraint stress. The obtained results expand the understanding of the most significant molecular targets for further research aimed at developing new therapeutic strategies for the prevention of the consequences of acute emotional stress, taking into account the hypertensive state of the patient.

Active avoidance learning in rats with different audiogenic epilepsy proneness

The success of the formation of the conditioned reflex reaction of two-way avoidance in the shuttle chamber in rats of 3 strains was evaluated. These were rats predisposed to audiogenic epilepsy – the Krushinsky-Molodkina strain rats (KM), "4" strain (selected from a population of F2 hybrids of the KM strain and sound-insensitive Wistars) and rats of "0" strain, selected for the absence of audiogenic epilepsy from the same population (i. e. these strains, diametrically different in audiogenic epilepsy proneness, possessing a similar genetic background). Experiments have shown significantly more successful assimilation of this skill in rats of the "0" strain.

Impact of varying sorbitol concentrations on hematological and biochemical blood parameters in Wistar rats (Rattus norvegicus)

Background: Sorbitol is an artificial sweetener that is very similar to natural sugar, but it is sweeter than natural sugar and lower in calories. Sorbitol is used as an alternative to natural sugar, and it is extracted from regular glucose. It does not have any negative effects on the animals’ health, and it is characterized in safe use in many scientific experiments for the diet of humans and animals.Methods: This study was conducted in the animal house, College of Veterinary Medicine, Al-Qasim Green University for a period of 90 days. Forty rats of the Wistar strain (Rattus norvegicus) were randomly distributed into 4 groups, namely the first group (control group) while the second, third and fourth groups were treated with 100, 200 and 300 μg of sorbitol/kg of body weight .The rats were iso in live weight and age at the beginning of the experiment. Blood samples were drawn at the end of the experimental period. Results: Increase in level dose of sorbitol resulted significant improvement in accounts of red blood cells, white blood cells, and a significant increase in level of hemoglobin, lymphocytes, and monocytes for second, third, and fourth groups compared to the control group. Moreover, the significant improvement in most of the blood parameters was reflected to significant increase in clotting and bleeding time in the second, third and fourth groups of rats compared to the control group. Also, the results showed a significant increase in the levels of FSH, LH, testosterone, Inhibin and MAD hormones for the second, third and fourth groups compared to the control group.Conclusions: The results of the current study revealed that sorbitol has many benefits in the diet of humans and animals and has an effect on blood indicators, some sex hormones and antioxidants in the body. It is recommended not to consume excessive sorbitol in the diet.Keywords: Sorbitol; Hematological parameters; FSH; LH; Wistar rats

Wound Healing Activity of Two Honeys from the Southern Regions of Senegal (Casamance)

Aim: The aim of this study was to evaluate the healing activity of two honeys from Casamance (Senegal) in a second-degree experimental burn model in the Wistar strain rat. Methodology: Experimental burns were induced using a metal cylinder 3 cm in diameter and heated for 5 min. The cylinder was applied for 20 seconds, pressing lightly on the surface of the rats' shaved skin to induce second-degree burns. Results: The daily application of honey induces a healing dependent on concentration and typology. The healing rate is higher with AF, with a score of 0.60 ± 0.48 vs 1.00 ± 0.00 for MZ which induces almost complete tissue repair after 21 days of treatment. Conclusion: The results of this study demonstrate the use of traditional honey in wound healing and burns.

Metabolic dysfunction-associated steatotic liver disease exhibits sex-specific microbial heterogeneity within intestinal compartments.

Evidence suggests that the gastrointestinal microbiome plays a significant role in the biology of metabolic dysfunction-associated steatotic liver disease (MASLD). However, it remains unclear whether disparities in the gut microbiome across intestinal tissular compartments between the sexes lead to MASLD pathogenesis. Sex-specific analyses of microbiome composition in two anatomically distinct regions of the gut, the small intestine and colon, were performed using an experimental model of MASLD. The study involved male and female spontaneously hypertensive rats and the Wistar-Kyoto control rat strain, which were fed either a standard chow diet or a high-fat diet for 12 weeks to induce MASLD (12 rats per group). High-throughput 16S sequencing was used for microbiome analysis. There were significant differences in the overall microbiome composition of male and female rats with MASLD, including variations in topographical gut regions. The beta diversity of the jejunal and colon microbiomes was higher in female rats than in male rats (PERMANOVA p-value=0.001). Sex-specific analysis and discriminant features using LEfSe showed considerable variation in bacterial abundance, along with distinct functional properties, in the jejunum and colon of animals with MASLD. Significantly elevated levels of lipopolysaccharide and protein expression of Toll-like receptor 4 were observed in the livers of male rats with MASLD compared with their female counterparts. This study uncovered sexual dimorphism in the gut microbiome of MASLD and identified microbial heterogeneity within intestinal compartments. Insights into sex-specific variations in gut microbiome composition could facilitate customised treatment strategies.

Perspectives on obesity imaging: [18F]2FNQ1P a specific 5-HT6 brain PET radiotracer.

Estimates suggest that approximatively 25% of the world population will be overweight in 2025. Better understanding of the pathophysiology of obesity will help to develop future therapeutics. Serotonin subtype 6 receptors (5-HT6) have been shown to be critically involved in appetite reduction and weight loss. However, it is not known if the pathological cascade triggered by obesity modifies the density of 5-HT6 receptors in the brain. Influence of diet-induced obesity (DIO) in Wistar rats was explored using MRI (whole-body fat) and PET ([18F]2FNQ1P as a specific 5-HT6 radiotracer). The primary goal was to monitor the 5-HT6 receptor density before and after a 10-week diet (DIO group). The secondary goal was to compare 5-HT6 receptor densities between DIO group, Wistar control diet group, Zucker rats (with genetic obesity) and Zucker lean strain rats. Wistar rats fed with high-fat diet showed higher body fat gain than Wistar control diet rats on MRI. [18F]2FNQ1P PET analysis highlighted significant clusters of voxels (located in hippocampus, striatum, cingulate, temporal cortex and brainstem) with increased binding after high-fat diet (p < 0.05, FWE corrected). This study sheds a new light on the influence of high-fat diet on 5-HT6 receptors. This study also positions [18F]2FNQ1P PET as an innovative tool to explore neuronal consequences of obesity or eating disorder pathophysiology.

Antisickling, hemolytic activities and toxicological evaluation of three plants species from the Nigerien Pharmacopoeia: Annona senegalensis Linné. Boscia senegalensis (Pers) Lam. and Ampelocissus afr

The aim of this study consits to evaluate the antisickling and antihemolytic activities and to determine the subacute toxicity of three plants Annona senegalensis L.; Boscia senegalensis (Pers) Lam.; and Ampelocissus africana (Lour) Merr.. The plant material contains leaves and bark of Annona senegalensis roots, leaves and bark root of Boscia senegalensis and the roots of Ampelocissus africana. A single method (80% ethanol maceration) is used to extract the five samples. The antisickleemic and antihemolytic effects are established with sickle cells disease (SCD) in the presence of sodium metabisulfite. Subacute toxicity is tested on Wistar strain rats. All samples showed an antisickling effect but leaves of Annona senegalensis (LAS) showed the highest percentage of antisickling activity (89.55%) at 50mg/ml. The anti-hemolytic effect was demonstrated in all samples by inhibition of hemolysis in the presence of a hemolysant. The toxicity results showed that the aqueous extracts of Annona senegalensis leaves and Boscia senegalensis root bark have non-toxic effects to wistar strain rats. However, some manifestations including fatigue, stretching and slight dyspenea were observed at doses of 150mg/mL and 300mg/mL. This work can contribute as a starting point towards the development of an improved traditional medicine (ITM) method which can help to treat the sickle cell disease. Keywords: Annona senegalensis L., Boscia senegalensis (pers) Lam and Ampelocissus Africana (Lour) Merr. Antisickness activity, Toxicity.

Identification of the genetic background of laboratory rats through amplicon-based next-generation sequencing for single-nucleotide polymorphism genotyping

BackgroundLaboratory rats, as model animals, have been extensively used in the fields of life science and medicine. It is crucial to routinely monitor the genetic background of laboratory rats. The conventional approach relies on gel electrophoresis and capillary electrophoresis (CE) technologies. However, the experimental and data analysis procedures for both of these methods are time consuming and costly.ResultsWe established a single-nucleotide polymorphism (SNP) typing scheme using multiplex polymerase chain reaction (PCR) and next-generation sequencing (NGS) to address the genetic background ambiguity in laboratory rats. This methodology involved three rounds of PCR and two rounds of magnetic bead selection to improve the quality of the sequencing data. We simultaneously analysed 100 laboratory rats (including rats of 5 inbred strains and 2 in-house closed colonies), and the sequencing depth varied from an average of 108.25 to 5189.89, with sample uniformity ranging from 82.5 to 97.5%. A total of 98.9% of the amplicons were successfully genotyped (≥ 30 reads). Genetic background analysis revealed that all 38 experimental rats from the 5 inbred strains were successfully identified (without a heterozygous allele). For the 2 in-house closed colonies, the average heterozygosity (0.162 and 0.169) deviated from the typical range of 0.5–0.7, indicating a departure from the ideal heterozygosity level. Additionally, we employed multiplex PCR-CE to validate the NGS-based method, which yielded consistent results for all the rat strains. These results demonstrated that this approach significantly improves efficiency, saves time, reduces costs and ensures accuracy.ConclusionBy utilizing NGS technology, our developed method leverages SNP genotyping for genetic background identification in laboratory rats, demonstrating advantages in terms of labour efficiency and cost-effectiveness, thereby rendering it well suited for projects involving extensive sample cohorts.

Current Overview of the Biology and Pharmacology in Sugen/Hypoxia-Induced Pulmonary Hypertension in Rats.

The Sugen 5416/hypoxia (Su/Hx) rat model of pulmonary arterial hypertension (PAH) demonstrates most of the distinguishing features of PAH in humans, including increased wall thickness and obstruction of the small pulmonary arteries along with plexiform lesion formation. Recently, significant advancement has been made describing the epidemiology, genomics, biochemistry, physiology, and pharmacology in Su/Hx challenge in rats. For example, there are differences in the overall reactivity to Su/Hx challenge in different rat strains and only female rats respond to estrogen treatments. These conditions are also encountered in human subjects with PAH. Also, there is a good translation in both the biochemical and metabolic pathways in the pulmonary vasculature and right heart between Su/Hx rats and humans, particularly during the transition from the adaptive to the nonadaptive phase of right heart failure. Noninvasive techniques such as echocardiography and magnetic resonance imaging have recently been used to evaluate the progression of the pulmonary vascular and cardiac hemodynamics, which are important parameters to monitor the efficacy of drug treatment over time. From a pharmacological perspective, most of the compounds approved clinically for the treatment of PAH are efficacious in Su/Hx rats. Several compounds that show efficacy in Su/Hx rats have advanced into phase II/phase III studies in humans with positive results. Results from these drug trials, if successful, will provide additional treatment options for patients with PAH and will also further validate the excellent translation that currently exists between Su/Hx rats and the human PAH condition.

Modulation of Blood Pressure through Microbiome Exchange between Milan Normotensive and Hypertensive Rat Strains

Modulation of Blood Pressure through Microbiome Exchange between Milan Normotensive and Hypertensive Rat Strains

Inter-Strain Differences in the Lumbar Spinal Cord Anatomy and Neuromorphology: Wistar Versus Dark Agouti Rats.

Rat strains differ in physiology, behavior, and recovery after central nervous system injury. To assess these differences, we compared the gross and local anatomy and neuromorphology of the lumbar spinal cord of the Wistar and Dark Agouti (DA) strains. The key findings include (i) distinct spatial relationships between vertebrae and spinal segments in the two strains; (ii) Wistar rats have larger volumes of spinal cord gray and white matter; (iii) DA rats have smaller total neuronal populations, thus indicating an expectation of smaller local neuronal populations; (iv) this expectation was confirmed for interneurons expressing calbindin 28kDa. But contrary to expectations, (v) DA rats had more numerous populations of the interneurons expressing parvalbumin and a population of α-motoneurons. Consequently, these strains displayed divergent ratios in specific spinal neuronal populations. Researchers should consider these inter-strain differences when comparing data across different strains.

Neuritogenesis and protective effects activated by Angiotensin 1–7 in astrocytes-neuron interaction

The renin angiotensin system (RAS) has been studied for its effects on various neurological disorders. The identification of functional receptors for Ang-(1–7) and Ang II peptides in astrocytes highlights the physiological modulation and the important role of these cells in the central nervous system. The present study aims to understand the role of RAS peptides, particularly Ang-(1–7) and Ang II, in the secretion of trophic factors by astrocytes and their effects on hippocampal neurons. We used primary cultures of astrocytes and neurons from the hippocampus of either sex neonate of Wistar strain rats. In the present study, we demonstrated that the treatment of astrocytes with Ang-(1–7) acts on the modulation of these cells, inducing reactive astrogliosis, identified through the increase in the expression of GFAP. Furthermore, we obtained a conditioned medium from astrocytes treated with Ang-(1–7), which in addition to promoting the secretion of neurotrophic factors essential for neuronal-glial interactions that are fundamental for neuritogenesis and neuronal survival, showed a neuroprotective effect against glutamatergic excitotoxicity. In turn, Ang II does not exhibit the same effects on astrocyte modulation, exacerbating deleterious effects on brain RAS. Neuron-astrocyte interactions have been shown to be an integral part of the central effects mediated by RAS, and this study has significantly contributed to the understanding of the biochemical mechanisms involved in the functioning of this system.

Three decades of rat genomics: approaching the finish(ed) line.

The rat, Rattus norvegicus, has provided an important model for investigation of a range of characteristics of biomedical importance. Here we survey the origins of this species, its introduction into laboratory research and the emergence of genetic and genomic methods that utilize this model organism. Genomic studies have yielded important progress and provided new insight into several biologically important traits. However, some studies have been impeded by the lack of a complete and accurate reference genome for this species. New sequencing and genome assembly methods applied to the rat have resulted in a new reference genome assembly, GRCr8, which is a near telomere-to-telomere assembly of high base level accuracy that incorporates several elements not captured in prior assemblies. As genome assembly methods continue to advance and production costs become a less significant obstacle, genome assemblies for multiple inbred rat strains are emerging. These assemblies will allow a rat pangenome assembly to be constructed which captures all the genetic variation in strains selected for their utility in research and will overcome reference bias, a limitation associated with reliance on a single reference assembly. By this means, the full utility of this model organism to genomic studies will begin to be revealed.

Erasure of DNA methylation in rat fetal germ cells is sex-specific and sensitive to maternal high-fat diet.

In mammals, DNA methylation (DNAme) erasure and reinstatement during embryo development and germline establishment are sensitive to the intrauterine environment. Maternal intake of a high-fat diet (HFD), associated with excessive gestational weight gain, has transgenerational effects on offspring health, which may be mediated by changes in DNAme in the germline. Here, we tested the impact of a maternal HFD on embryonic germline DNAme erasure using a rat strain that expresses green fluorescent protein specifically in germ cells. DNAme was analysed by methyl-seq capture in germ cells collected from male and female F1 gonads at gestational day 16. Our data show that although HFD induced global hypomethylation in both sexes, DNAme erasure in female germ cells was more advanced compared to male germ cells. The delay in DNAme erasure in males and the greater impact of HFD suggest that male germ cells are more vulnerable to alterations by exogenous factors.

The involvement of proinflammatory cytokines in the pathogenesis of audiogenic epilepsy

Epilepsy is a heterogeneous disease, which determines the relevance of investigating the mechanisms of pathogenesis of its various types, including reflex epilepsy. Pharmacotherapy is common for the treatment of patients with epilepsy, however, despite the significant recent achievements, 20-30% of patients remain resistant to the ongoing treatment. The urgency of creating new antiepileptic drugs, in particular, immune ones is due not only to a significant proportion of pharmacoresistant cases, but also to the struggle for the quality of life of patients. The neuroinflammation system in animals with different genetically determined audiogenic epilepsy proneness was investigated. These genetic groups were Krushinsky–Molodkina rats (tonic seizures of maximum intensity in response to the action of sound) and “0” strain (control group, non-convulsive phenotype). The main proinflammatory cytokines levels in the dorsal striatum and brain stem in rats of these genetic groups were measured by multiplex immunofluorescence assay. Background levels of IL-1â, IL-6 and TNFá in the dorsal striatum of KM rats were significantly lower than in the control “0” strain rats, whereas in the brain stem in the “background” levels of these metabolites did not differ. Four hours after the sound exposure, the TNFá level in the dorsal striatum of KM rats was significantly lower than in “0” rats. In KM rats, after the sound exposure and subsequent tonic seizures, the levels of IL-1â and IL-6 in the dorsal striatum were significantly higher than in the background. The IL-2 content was not detected in the background in KM rats, whereas after audiogenic seizures its level was 14.01 pg/ml. In the brain stem of KM rats, the levels of IL-1â and TNFá after audiogenic seizures were significantly lower than in the background. In rats of the “0” strain, cytokine levels in the dorsal striatum after the sound exposure did not differ from those in the background, while IL-1ß levels in their brain stem were significantly lower than the background state. Particular modulating role of the studied proinflammatory cytokines in the pathogenesis of audiogenic epilepsy is assumed, as well as certain possibility of anti-inflammatory and immune drugs application in anticonvulsant and antiepileptic therapy.

Contrasting Effects of Oxytocin on MK801-Induced Social and Non-Social Behavior Impairment and Hyperactivity in a Genetic Rat Model of Schizophrenia-Linked Features.

Social withdrawal in rodents is a measure of asociality, an important negative symptom of schizophrenia. The Roman high- (RHA) and low-avoidance (RLA) rat strains have been reported to exhibit differential profiles in schizophrenia-relevant behavioral phenotypes. This investigation was focused on the study of social and non-social behavior of these two rat strains following acute administration of dizocilpine (MK801, an NMDA receptor antagonist), a pharmacological model of schizophrenia-like features used to produce asociality and hyperactivity. Also, since oxytocin (OXT) has been proposed as a natural antipsychotic and a potential adjunctive therapy for social deficits in schizophrenia, we have evaluated the effects of OXT administration and its ability to reverse the MK801-impairing effects on social and non-social behavior and MK801-induced hyperactivity. MK801 administration produced hyperlocomotion and a decrease in social and non-social behavior in both rat strains, but these drug effects were clearly more marked in RHA rats. OXT (0.04 mg/kg and 0.2 mg/kg) attenuated MK801-induced hyperlocomotion in both rat strains, although this effect was more marked in RHA rats. The MK801-decreasing effect on exploration of the "social hole" was moderately but significantly attenuated only in RLA rats. This study is the first to demonstrate the differential effects of OXT on MK801-induced impairments in the two Roman rat strains, providing some support for the potential therapeutic effects of OXT against schizophrenia-like symptoms, including both a positive-like symptom (i.e., MK801-induced hyperlocomotion) and a negative-like symptom (i.e., MK801 decrease in social behavior), while highlighting the importance of the genetic background (i.e., the rat strain) in influencing the effects of both MK801 and oxytocin.

Haplotype variability in mitochondrial rRNA predisposes to metabolic syndrome

Metabolic syndrome is a growing concern in developed societies and due to its polygenic nature, the genetic component is only slowly being elucidated. Common mitochondrial DNA sequence variants have been associated with symptoms of metabolic syndrome and may, therefore, be relevant players in the genetics of metabolic syndrome. We investigate the effect of mitochondrial sequence variation on the metabolic phenotype in conplastic rat strains with identical nuclear but unique mitochondrial genomes, challenged by high-fat diet. We find that the variation in mitochondrial rRNA sequence represents risk factor in the insulin resistance development, which is associated with diacylglycerols accumulation, induced by tissue-specific reduction of the oxidative capacity. These metabolic perturbations stem from the 12S rRNA sequence variation affecting mitochondrial ribosome assembly and translation. Our work demonstrates that physiological variation in mitochondrial rRNA might represent a relevant underlying factor in the progression of metabolic syndrome.