Female Rats Research Articles

Investigation of the Relationship Between Brown HT Dye Exposure and Mammary Tumor Development in Female Rats: An Assessment of the Potential Risk of Breast Cancer

Investigation of the Relationship Between Brown HT Dye Exposure and Mammary Tumor Development in Female Rats: An Assessment of the Potential Risk of Breast Cancer

Fertility protective effects of Brillantaisia patula leaf extract against cyclophosphamide-induced ovarian damage in Wistar rats

BackgroundThe primary indication of infertility is the incapacity to conceive, and in females, the majority of instances of female infertility stem from ovulation disorders. This study evaluated the female fertility-enhancing effects and safety of aqueous leaf extract of Brillantaisia patula (ALEBP) in a cyclophosphamide (CYP) model of sterility in Wistar rats.MethodSixty-six female rats randomly allotted to six groups (n = 11) were administered with the appropriate regimen for 21 days and then mated with male rats. Group 1 (control) received distilled water. Groups 2–6 were treated with a single dose (200 mgkg− 1 body weight) of cyclophosphamide intraperitoneally and, in addition, received the same volume (0.5 mL) of distilled water, 18, 36, 72 mgkg− 1 body weight of ALEBP and 200 mg per body weight of vitamin C orally. Mating lasted 11 days; on day 20, the female Wistar rats were sacrificed. Data were analysed using One-way Analysis of Variance (ANOVA) followed by Dunett’s posthoc analysis, and GraphPad (at p < 0.05).ResultsResults herein showed that ALEBP significantly (p < 0.05) increased the diminution in activities/levels of glutathione peroxidase (GPx), reduced glutathione (GSH), total antioxidant capacity (TAC), cholesterol, alkaline phosphatase (ALP), acid phosphatase (ACP), estrogen (ES), and luteinising hormone (LH) induced by cyclophosphamide. ALEBP further reversed the increased level of malondialdehyde (MDA), tumour necrosis factor-α (TNFα), interleukin 8 (IL-8), and follicle-stimulating hormone (FSH) caused by cyclophosphamide (p < 0.05). In addition, ALEBP, while it significantly increased the cyclophosphamide-induced reduction in the number of implantations in each animal, the total number of viable fetuses, the total number of corpora lutea, and the fertility index, also significantly reduced the number of fetal resorptions in each animal and pre-implantation loss that was increased by cyclophosphamide. Moreover, the cyclophosphamide-induced degenerative and necrotic changes in the ovarian cells and uterus were reversed by ALEBP.ConclusionsConsidered as a whole, the aqueous leaf extract of Brillantaisia patula reversed oxidative stress and inflammatory side effects of cyclophosphamide, preserving ovarian function and fertility in the rats. This may suggest its exploration as a safe agent against toxic side effects of chemotherapy and fertility-related disorders of the uterus and ovary.

High dose of liraglutide impairs renal function in female hypertensive rats

Glucagon-like peptide-1 (GLP-1) receptor agonists exhibit beneficial cardiovascular effects. However, the renal effects of different doses of liraglutide in an essential hypertension model have not yet been investigated. SHR female rats were treated for 30 days, twice a day, with saline (control) or liraglutide at low (0.06 mg/kg, LL) and high (0.6 mg/kg, LH) doses. Volume intake and excretion were monitored for a period of 24h. In renal tissue, nitrite-NO2 -, nitrate-NO3 -, advanced protein oxidation products-AOPP, collagen deposition, creatinine (Cr), urea (U), sodium, and potassium were analyzed. liraglutide reduced body weight gain in both groups. However, in the high dose, it increased urinary volume excretion and sodium/potassium ratio. Both doses reduced the urinary U/Cr ratio and LH increased the serum U/Cr ratio. AOPP was reduced only in LL. LH augmented collagen and early markers of kidney injury (blood urea nitrogen-BUN, BUN/Cr). LH increased NO3 -, reduced NO2 -, and caused an aberrant increase in GFR. Both doses’ effects were independent of blood pressure and glycemic control. liraglutide appears to have distinct effects on the hypertensive female kidney depending on the dose, with higher doses impairing kidney function.

Sex differences in expression of CGRP family of receptors and ligands in the rat trigeminal system

BackgroundCalcitonin gene-related peptide (CGRP) is part of the calcitonin peptide family, which includes calcitonin (CT), amylin (AMY), and adrenomedullin (ADM). CGRP and its receptor are highly present in the trigeminovascular system (TVS). Recent research suggests that other members of the calcitonin family could be feasible therapeutic targets in the treatment of migraine. The present study aims to elucidate the distribution of ADM, AMY, CT, and their receptors in the rat TVS, and to explore potential sex differences in their expression.MethodsTrigeminal ganglia (TG) were dissected from male and female adult rats. Protein and gene expression were assessed through immunohistochemistry and RT-qPCR. Additionally, the dura mater was isolated for further investigation of protein expression and fiber localization using immunohistochemistry.ResultsQuantitative gene expression analysis revealed the presence of all genes in male and female TGs, except for calcitonin receptor (CTR). Notably, CGRP mRNA levels in TG were several folds higher than those of other genes. The receptor activity-modifying protein-1 (RAMP1) mRNA levels were significantly higher in female compared to male.No AMY or CT immunoreactivity was observed in the TVS. In contrast, immunoreactivity for ADM, CGRP, RAMP1, CTR, and calcitonin-like receptor (CLR) were observed in the cytoplasm of TG neurons. Immunoreactive Aδ-fibers storing RAMP1, ADM and CLR were also identified. RAMP2 and RAMP3 were expressed in nucleus of TG neurons and in satellite glial cells. Furthermore, RAMP1 and CLR were co-localized with CASPR in the nodes of Ranvier located in Aδ-fibers.ConclusionsThis study provides valuable insights into the distribution of the CGRP family of peptides and their receptors in the TVS. CGRP mRNA levels in the TG were markedly higher than those of other genes, demonstrating the key role of CGRP. The co-localization of CLR and RAMP1 on Aδ-fibers with CASPR suggests a potential role for this receptor in modulating trigeminal nerve function and neuronal excitability, with implications for migraine pathophysiology. Additionally, RAMP1 mRNA levels were significantly higher in female TG compared to males, indicating sex-specific differences in gene expression. These findings underscore the need for further research into the functional significance of gender-related variations.

Huyang Yangkun formula regulates the mitochondria pathway of ovarian granulosa cell apoptosis through FTO/m6A-P53 pathway

BackgroundPremature ovarian insufficiency (POI) presents a significant challenge to female reproductive health. The Huyang Yangkun Formula (HYF), a traditional Chinese medicinal formulation, has been utilized in clinical settings for the treatment of POI for over a decade. Nevertheless, the therapeutic application of HYF is considerably constrained by the lack of clarity regarding its underlying mechanism of action.MethodsThe experimental procedures entailed administering VCD to female Sprague-Dawley rats at a dosage of 160 mg/kg/day over a period of 15 days, succeeded by a 100-day treatment with HYF. Blood serum samples were collected and analyzed using ELISA to quantify the concentrations of Anti-Müllerian Hormone (AMH), Follicle-Stimulating Hormone (FSH), and Estradiol (E2). The levels of N6-methyladenosine (m6A) were assessed through Dot blot analysis and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Western blotting was employed to validate the differential expression of m6A-related catalytic enzymes and apoptosis-related regulators, including BCL-2, BCL-XL, and MCL-1, which may be implicated in the effects of HYF. Certain shRNA-COV434 cell line was constructed for the exploration of molecular mechanism, and then the potential targets were finally verified by MeRIP-qPCR.ResultsHYF has been identified as having a significant influence on the development of residual ovarian follicles in rats with POI, especially during the initial stages. It was observed that HYF facilitates the progression of escaping antral follicles to full maturation. Additionally, HYF exhibited the capacity to enhance the proliferation of COV434, a human ovarian granulosa cell line, while concurrently inhibiting apoptosis within these cells. Notably, HYF treatment resulted in the downregulation of apoptotic proteins, including BCL-XL, cleaved-caspase 9, cleaved-caspase 3, and Bcl-2. Concurrently, m6A modification is implicated in the regulation of HYF. Both in vitro and in vivo studies indicate that FTO may play a role in the anti-apoptotic mechanisms mediated by m6A in ovarian granulosa cells influenced by HYF. Moreover, employing qPCR and MeRIP-qPCR techniques, P53 has been identified as the target gene for m6A modification mediated by FTO.ConclusionThese findings suggest that HYF holds promise as a potential treatment for POI and provide a more comprehensive understanding of the mechanism by which HYF operates, specifically its ability to prevent the BCL-2 mitochondrial apoptosis pathway mediated by P53 in ovarian granulosa cells of POI rats by regulating FTO/m6A-Tp53.

The Interaction of Apical Periodontitis, Cigarette Smoke, and Alcohol Consumption on Liver Antioxidant Status in Rats

This study aimed to investigate the impact of alcohol (A), secondhand cigarette smoking (ShS), and their combined effect on liver antioxidant activity and hepatic damage in rats with induced apical periodontitis (AP). Thirty-five female Wistar rats were randomly allocated into five groups (n = 7): (1) control (rats without ShS, alcoholic diet, or AP), (2) control-AP (induced AP only), (3) ShS-AP (ShS exposure and induced AP), (4) A-AP (alcoholic diet and induced AP), and (5) A+ShS-AP (alcoholic diet, ShS exposure, and induced AP). Alcohol was administered through semi-voluntary intake, while ShS exposure involved the daily inhalation of cigarette smoke. The experimental period lasted 8 weeks, with AP induction occurring in the 4th week following molar pulp exposure. Liver samples were collected post-euthanasia for histomorphometric and antioxidant marker analyses. All AP-induced groups exhibited increased liver sinusoidal dilation compared to the control group (p &lt; 0.05). AP significantly reduced total antioxidant capacity (FRAP) across all groups (p &lt; 0.05). In AP-induced groups, FRAP levels were further decreased in ShS-AP and A+ShS-AP compared to control-AP (p &lt; 0.05). AP also led to a decrease in the glutathione defense system (p &lt; 0.05). Rats with alcohol exposure (A-AP and A+ShS-AP) showed reduced glutathione peroxidase activity (p &lt; 0.05). Glutathione reductase activity was comparable in the control and control-AP groups (p &gt; 0.05), but significantly decreased in the alcohol and ShS-exposed groups (p &lt; 0.05). Apical periodontitis can relate to morphological changes in the liver’s sinusoidal spaces and impairment of liver’s antioxidant capacity of rats, particularly when combined with chronic alcohol consumption and exposure to cigarette smoke.

Ginger Extract Improves Cognitive Dysfunction via Modulation of Gut Microbiota-Derived Short-Chain Fatty Acids in D-Galactose/Ovariectomy-Induced Alzheimer-Like Disease.

Alzheimer's disease (AD) is the most common form of dementia with complex causes and limited treatment options. Recent research has suggested a connection between the progression of AD and the activity of gut microbiota. Ginger, a plant known for its anti-inflammatory, antioxidant, and neuroprotective properties, has gained attention as a potential treatment for alleviating AD symptoms. In this study, we induced an AD model in female rats through ovariectomy and D-galactose injection and then investigated the protective effects of oral administration of ginger ethanolic extract. We assessed changes in short-chain fatty acids (SCFAs), learning and memory abilities, neuroinflammatory markers in plasma, and the hippocampus, as well as histological changes in the intestine and hippocampus in sham-operated, diseased, and treatment groups. Oral administration of ginger ethanolic extract improved gut microbiota activity, increased SCFA levels, and enhanced the expression of tight junction proteins. Additionally, ginger extract reduced the concentrations of TNF-α and IL-1β in both plasma and the hippocampus. Furthermore, it significantly reduced cell death and amyloid plaque deposition in the hippocampal tissue. These physiological changes resulted in improved performance in learning and memory tasks in rats treated with ginger compared with the disease group. These findings provide compelling evidence for the beneficial effects of ginger on the gut-brain axis, leading to improvements in learning and memory through the reduction of neuroinflammation.

APOE4 rat model of Alzheimer’s disease: sex differences, genetic risk and diet

The strongest genetic risk factor for Alzheimer’s disease (AD) is the ε4 allele of apolipoprotein E (ApoE ε4). A high fat diet also adds to the risk of dementia and AD. In addition, there are sex differences as women carriers have a higher risk of an earlier onset and rapid decline in memory than men. The present study looked at the effect of the genetic risk of ApoE ε4 together with a high fat/high sucrose diet (HFD/HSD) on brain function in male and female rats using magnetic resonance imaging. We hypothesized female carriers would present with deficits in cognitive behavior together with changes in functional connectivity as compared to male carriers. Four-month-old wildtype and human ApoE ε4 knock-in (TGRA8960), male and female Sprague Dawley rats were put on a HFD/HSD for four months. Afterwards they were imaged for changes in function using resting state BOLD functional connectivity. Images were registered to, and analyzed, using a 3D MRI rat atlas providing site-specific data on 173 different brain areas. Resting state functional connectivity showed male wildtype had greater connectivity between areas involved in feeding and metabolism while there were no differences between female and male carriers and wildtype females. The data were unexpected. The genetic risk was overshadowed by the diet. Male wildtype rats were most sensitive to the HFD/HSD presenting with a deficit in cognitive performance with enhanced functional connectivity in neural circuitry associated with food consumption and metabolism.

Does Ovariectomy Affect the Mechanics of the Mandibular Alveolar Bone Structure of Wistar Rats Subjected to Tooth Loss and Modified Diet?—A FEA Study

The aim of this study was to evaluate the mechanical effect of ovariectomy, diet, and tooth extraction on the bone structure of the mandible of Wistar rats. Mandibles from 40 female Wistar rats were used, divided into rats with ovariectomy surgery or surgical simulation. Half of the rats had the right upper incisor extracted and a soft diet was introduced for half of the animals for 30 days. After euthanasia, microtomography of the mandibles was performed for bone segmentation to construct three-dimensional models. Each mandible was subjected to a three-point bending test. The simulation by finite element method was configured according to the protocol for positioning the part on the support and force action by the load cell defined in the mechanical tests. Stress dissipation was described qualitatively on a color scale distributed in ranges of stress values. All models showed a higher concentration of stresses in the regions of force action and in the support regions, with differences in stress values and locations. Diet and dental condition interfered in the distribution of stresses, with the lateral surface of the mandible being more influenced by diet and the medial surface of the mandible by diet and dental condition.

Therapeutic potential of hyaluronic acid hydrogel combined with bone marrow stem cells-conditioned medium on arthritic rats’ TMJs

Conditioned media (CM) is derived from mesenchymal stem cells (MSC) culture and contains biologically active components. CM is easy to handle and reduces inflammation while repairing injured joints. Combination therapy of the CM with cross-linked hyaluronic acid (HA) could ameliorate the beneficial effect of HA in treating degenerative changes of articulating surfaces associated with arthritic rats’ temporomandibular joints (TMJs). This study aimed to evaluate the therapeutic potential of HA hydrogel combined with bone marrow stem cells-conditioned medium (BMSCs-CM) on the articulating surfaces of TMJs associated with complete Freund’s adjuvant (CFA)-induced arthritis. Fifty female Sprague-Dawley rats were divided randomly into five equal groups. Rats of group I served as the negative controls and received intra-articular (IA) injections of 50 µl saline solution, whereas rats of group II were subjected to twice IA injections of 50 µg CFA in 50 µl; on day 1 of the experiment to induce persistent inflammation and on day 14 to induce arthritis. Rats of group III and IV were handled as group II and instead, they received an IA injection of 50 µl HA hydrogel and 50 µl of BMSCs-CM, respectively. Rats of group V were given combined IA injections of 50 µl HA hydrogel and BMSCs-CM. All rats were euthanized after the 4th week of inducing arthritis. The joints were processed for sectioning and histological staining using hematoxylin and eosin, Masson’s trichrome and toluidine blue special staining, and immunohistochemical staining for nuclear factor-kappa B (NF-κB). SPSS software was used to analyze the data and one-way analysis of variance followed by post-hoc Tukey statistical tests were used to test the statistical significance at 0.05 for alpha and 0.2 for beta. In the pooled BMSC-CM, 197.14 pg/ml of platelet-derived growth factor and 112.22 pg/ml of interleukin-10 were detected. Compared to TMJs of groups III and IV, TMJs of group V showed significant improvements (P = 0.001) in all parameters tested as the disc thickness was decreased (331.79 ± 0.73), the fibrocartilaginous layer was broadened (0.96 ± 0.04), and the amount of the trabecular bone was distinctive (19.35 ± 1.07). The mean values for the collagen amount were increased (12.29 ± 1.38) whereas the mean values for the NF-κB expression were decreased (0.62 ± 0.15). Combination therapy of HA hydrogel and BMSCs-CM is better than using HA hydrogel or BMSCs-CM, separately to repair degenerative changes in rats’ TMJs associated with CFA-induced arthritis.

Transuterine relocation of pregnant uterine horn segment in an exploratory rat model with implications for tubal ectopic pregnancy

Ectopic pregnancy affects ~ 2% of pregnancies annually in the United States, with no current treatments allowing for the continuation of the pregnancy. Thus, this study sought to initiate an investigation into the potential design of a surgical technique, in an animal model, that could serve as a foundation for future research into the potential of relocating an ectopic embryo into the uterus at the human level. Female Long-Evans rats were randomly assigned to one of two groups: Embryo Relocation (ER; n = 12; underwent embryo relocation surgery) and Normal Pregnancy (NP; n = 12; carried a normal pregnancy; no surgery). Eight rats/group were allowed to carry their pregnancy to term and deliver, while four had their uteri collected at the end of gestation. Briefly, for the ER group, a uterine horn containing 1–2 embryos was translocated to the contralateral horn, which had been incised and cleared of its contents, prior to being wrapped around the relocated horn. Rat weight, food consumption and vaginal impedance of the mothers were measured throughout the experiment. Ultrasounds were performed and fetal heart rates measured on day 20–21 of gestation. Additionally, rat weight of all offspring was measured at adulthood. Our findings indicate that, in the ER group, 15/15 (100%) of the relocated embryos had detectable heart rates at the end of gestation (within the normal range), 14/15 (93%) were delivered vaginally, and 12/14 (86%) survived until adulthood. A significant decrease in rat weight and food consumption was observed only on the day following surgery. Fertility, as measured by vaginal impedance, was minimally impacted by surgery. Moreover, there was no significant difference between groups in average body weight of offspring at adulthood. Histological analysis indicated a thicker placenta in the ER group, attributable to the fetal part of the placenta, potentially indicating compensatory mechanisms. Our findings reflect a successful transuterine embryo relocation followed by vaginal birth and survival of offspring to adulthood, in a rat model. Such findings lay the foundation for future preclinical research in higher animals, with potential implications on a procedure relevant to human ectopic embryo relocation.

Curcumin Mitigates Muscle Atrophy Potentially by Attenuating Calcium Signaling and Inflammation in a Spinal Nerve Ligation Model

Denervation-induced calcium/calmodulin-dependent protein kinase II (CaMKII) activation and inflammation can result in muscle atrophy. Curcumin and bisdemethoxycurcumin are well known to exhibit an anti-inflammatory effect. In addition, curcumin has been shown to attenuate CaMKII activation in neuronal cells. This study aimed to examine the effect of curcumin or bisdemethoxycurcumin on CaMKII activation, inflammation, and muscle cross-sectional area (CSA) in spinal nerve ligated rats. Sixteen female rats were assigned to sham (CON), spinal nerve ligation (SNL), SNL+ curcumin 100 mg/kg BW (100CUR), and SNL+ bisdemethoxycurcumin 50 mg/kg BW (50CMO) for 4 weeks. Ipsilateral (surgical) soleus and tibialis anterior (TA) muscles was stained for dystrophin to measure CSA. Ipsilateral and contralateral (non-surgical) plantaris muscles were analyzed for protein content for acetylcholine receptor (AChR), CaMKII, CaMKIIThr286, nuclear factor-κB (NF-κB), NF-κBSer536, and interleukin-1β (IL-1β) and normalized to α-tubulin and then CON. A significant (p &lt; 0.050) group effect was observed for TA CSA where CON (11,082.25 ± 1617.68 μm2; p &lt; 0.001) and 100CUR (9931.04 ± 2060.87 μm2; p = 0.018) were larger than SNL (4062.25 ± 151.86 μm2). In the ipsilateral plantaris, the SNL (4.49 ± 0.69) group had greater CaMKII activation compared to CON (1.00 ± 0.25; p = 0.010), 100CUR (1.12 ± 0.45; p = 0.017), and 50CMO (0.78 ± 0.19; p = 0.009). The ipsilateral plantaris (2.11 ± 0.66) had greater IL-1β protein content than the contralateral leg (0.65 ± 0.14; p = 0.041) in the SNL group. In plantaris, the SNL (1.65 ± 0.51) group had greater NF-κB activation compared to CON (1.00 ± 0.29; p = 0.021), 100CUR (0.61 ± 0.10; p = 0.003), 50CMO (0.77 ± 0.25; p = 0.009) groups. The observed reduction in Ca2+ signaling and inflammation in type II plantaris muscle fibers might reflect the changes within the type II TA muscle fibers which may contribute to the mitigation of TA mass loss with curcumin supplementation.

RETRACTED - Cell transcription dependent on Wingless-type (Wnt)/beta-catenin in the rat estrous cycle stages

Objectives: We aimed to evaluate how T Cell Factor 7 Like 2 (TCF7L2) and Lymphoid Enhancer Factor-1 (LEF-1), which regulate cell transcription, regulate implantation in the endometrium. Methods: Female rats were determined according to the estrous cycle. The obtained uterine tissues were taken for immunofluorescence staining. Results: In estrous, LEF-1 and TCF7L2 showed localization in perimetrial-myometrial connective tissue. Of all the signaling molecules, the TCF7L2 molecule is the only one that is expressed. Non-expressed TCF7L2 in the uterine epithelium showed strong immunolocalization in the perimetrial myometrial connective tissue and endometrial basal stroma area. LEF-1 was mostly expressed in the metaestrus phase in the areas of gland epithelium. Conclusions: TCF7L2 and LEF-1 play a critical role in cell proliferation, differentiation and transcription by regulating the activation of the Wnt signaling pathway in endometrial cells. These findings help us to understand the role of TCF7L2 and LEF-1 in the provision of endometrial homeostasis and in the implantation process.

Distribution of progesterone receptors and the membrane component of progesterone receptor in various organs and tissues of male and female rats

Progesterone regulates reproductive processes and affects many functions of various non-reproductive organs. Its effects in mammals and humans are mediated by nuclear (nPRs) and membrane progesterone receptors (mPRs). The action of progesterone through different types of receptors may differ significantly and has tissue specific features. The expression of known types and subtypes of progesterone receptors in the tissues of male and female rats has been studied fragmentarily. The purpose of our work was to study the expression of five mPRs genes, as well as the nPRs gene and the membrane component of the progesterone receptor PGRMC I in the reproductive organs and in 17 non-reproductive tissues of male and female rats using reverse transcription followed by real-time PCR. In this study, it was shown that a high level of nPRs gene expression in rats is found not only in reproductive organs of females (uterus, ovary, mammary glands), but also in seminal vesicles of males, in the brain and trachea of both sexes, in blood vessels, and in the pancreas of females. The highest level of expression of mPRs genes of all subtypes was found in the testes, while expression of the gene encoding nPRs was practically undetectable in them. Expression of genes encoding mPRs was also detected in the liver and spleen of male and female rats, while expression of the gene encoding nPRs was at background levels. Virtually no expression of nPRs, mPRs, and membrane component of progesterone receptor (PGRMC I) genes was detected in muscle, and its level was very low in the heart in animals of both sexes. We found sex-specific differentiation of nuclear and membrane receptor mRNA levels in rats in non-reproductive tissues, characterized by a predominance of nPRs transcripts and three subtypes of mPRs (α, β, δ) in females and two subtypes of mPRs (γ, ε) in males. Data on the presence of progesterone receptors in tissues not involved in reproduction confirm the effect of progesterone on these organs. High levels of mRNA for various progesterone receptors in the tissues of male rats, such as the pancreas, lungs, kidney, and trachea, indicate an important physiological role of progestins not only in females, but also in males, which is still poorly understood. The work also discusses the known functions of progesterone receptors in the tissues studied.

Sex influence on serotonergic modulation of the vascular noradrenergic drive in rats.

In male rats, the serotonergic system modulates sympathetic outflow at vascular levels, causing sympatho-inhibition and sympatho-excitation, mainly via 5-HT1D/1A and 5-HT3 receptors, respectively. However, sex influence on vascular serotonergic regulation has not yet been elucidated. This study aimed to analyse the 5-HT sympatho-modulatory role in female rats, characterising the 5-HT receptors involved. Female Wistar (14- to 16-week-old) rats were prepared for sympathetic stimulation. Mean blood pressure (MBP) and heart rate (HR) were continuously measured. Vasopressor responses were obtained by electrical stimulation of the sympathetic outflow (0.1-5 Hz) or i.v. noradrenaline (0.01-0.5 μg·kg-1). 5-HT-related drug effects on adrenergic system were determined. Age-matched male rats were used as control. Basal MBP in females was lower than in male rats, whereas electrical-induced increases in MBP were similar. In females, 5-HT exerted a dose-dependent inhibition on the sympathetic-evoked vasoconstrictions, that was reproduced by some agonists; 5-CT (5-HT1/5/7) and L-694,247 (5-HT1D), whereas the selective 5-HT2A/2B/2C (α-methyl-5-HT) and 5-HT3 agonist (1-PBG) increased the electrically-produced vasopressor responses. None of the other drugs tested (targeting 5-HT1A/1B/1F, 5-HT2B/2C, 5-HT4, 5-HT5A or 5-HT7) modified these vasoconstrictions. Only 1-PBG (5-HT3) modified the vasoconstrictions induced by exogenous noradrenaline. In female rats, vascular serotonergic sympatholytic effects are due to prejunctional 5-HT1D receptor activation, whereas pre and/or postjunctional 5-HT3 and prejunctional 5-HT2A receptor activation is involved in the potentiating effect of vascular sympathetic neurotransmission. These findings may open novel sex-differential therapeutic strategies for treating cardiovascular conditions.

The Role of Probiotics in Modulating Myocardial Infarction and Depression-like Symptoms: A Study on Sex-Specific Responses

Background/Objectives: This study explores the effects of two probiotics, Lactobacillus helveticus R0052 and Bifidobacterium longum R0175, on myocardial infarction (MI) and associated depression-like behaviours, with a focus on sex differences. Methods: MI was induced in adult male and female rats by occluding the left anterior coronary artery for 30 min, followed by 24 h of reperfusion. Probiotics were administered via drinking water for at least two weeks before ischemia. Infarct size, plasma C-reactive protein (CRP), estradiol levels, and intestinal permeability were then measured. Two weeks after, MI subgroups of rats were tested for depression-like behaviours. Results: We found a significant interaction between sex and probiotics in relation to infarct size. Probiotics significantly reduced the infarct size compared to the vehicle group in female rats but not in males. Probiotics increased the plasma estradiol levels and reduced the CRP concentrations in females, suggesting anti-inflammatory and cardioprotective properties. Probiotics significantly increased intestinal resistance following MI in males only, suggesting sex-specific physiological responses to treatment. Probiotics enhanced social interaction in males with MI but not in females. Similarly, in the forced swim test, probiotics reduced immobility in males with MI but increased it in females, further underscoring the sex-dependent effects of probiotics. Conclusions: This study reports cardioprotective effects of probiotics upon MI in female rats, while benefits in male rats were rather at the behavioural level. These results highlight distinct physiological and behavioural responses between sexes, emphasizing the need to account for sex differences in future tests of probiotics as a prophylactic treatment for MI.

Effect of ethyl acetate extract from Usnea longissima on chemotherapy-associated multiple organ dysfunction in rats

BackgroundThe toxic effects of doxorubicin and cisplatin in various organs have been associated with oxidative stress. Studies have shown that Usnea longissima has strong antioxidant effects. This study aimed to investigate the protective effect of ethyl acetate extract from Usnea longissima (ULE), which is known to have strong antioxidant effects, on chemotherapeutic-induced heart, kidney, liver, and ovarian toxicity. MethodsAlbino Wistar female rats were divided into five groups (12 rats per group): healthy (HG), doxorubicin (DOX), Cisplatin (CIS), Doxorubicin+ ULE (DULE), Cisplatin+ ULE (CULE). In this experiment, ULE was given 100 mg/kg orally. After 1 hour, 2.5 mg/kg doxorubicin and 2.5 mg/kg cisplatin were administered intraperitoneally. Drug treatments continued once a day for seven days. At the end of seven days, six rats from each group were euthanized and heart, kidney, liver, and ovary tissues were analyzed biochemically. The remaining rats were left in the laboratory with male rats for 45 days for reproduction. ResultsULE inhibited chemotherapeutic-induced increase in malondialdehyde, tumor necrosis factor-alpha, and interleukin 6 and a decrease in total glutathione in liver, kidney, and ovarian tissues. ULE also inhibited the increase of blood urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase in serum. ULE treatment had no protective effect against doxorubicin and cisplatin cardiac toxicity. On the other hand, ULE also decreased the delay in pregnancy induced by chemotherapy. ConclusionULE may be considered an adjuvant therapy in patients receiving chemotherapy to reduce liver, kidney, and ovarian toxicity.

Effects of NMDA glutamatergic receptors pharmacological stimulation of the ventral tegmental area on the memory deficits induced by maternal deprivation

Maternal deprivation (MD) is a potent stressor during early life and can lead to behavioral changes during adulthood. Several neurochemical mechanisms underlying MD-induced stress have been proposed; among them is the damage caused to dopaminergic neurons in the ventral tegmental area (VTA). We hypothesized that pharmacological stimulation of dopaminergic neurons in VTA by the infusion of an N-Methyl-D-Aspartate (NMDA) receptors agonist (used considering the wide distribution of these glutamatergic receptors in the VTA neurons) can reverse MD-induced memory deficits. Here, we demonstrated that MD affects male and female rats distinctly, with females being more resilient to early-life stress. Furthermore, NMDA pharmacological stimulation of the VTA promotes object recognition (OR) memory persistence in male and female non-MD rats. In males, infusion of NMDA into the VTA immediately after the learning session reverses recognition memory deficits related to MD. Although MD female rats have not shown deficits in OR memory consolidation, the NMDA infusion immediately after the learning session promotes memory persistence. We verified that MD leads to memory deficits in adult male rats, while the females are resilient to early life stress. Furthermore, NMDA pharmacological stimulation of dopaminergic VTA neurons reveals the dopaminergic modulation of OR memory in MD rats, even in females that did not exhibit memory deficits.

Effects of Early Life Scarcity-Adversity on Maturational Milestones in Male and Female Rats.

Although many studies have shown a long-term negative impact of early life adversity (ELA) in rodents, literature regarding its effects on maturational milestones in rats is scarce. Available evidence suggests that ELA interferes with normal growth and development in rodents and that effects may be sex-dependent even at an early age. In accordance, we hypothesized that early life scarcity-adversity would impair physical and reflex development in male and female rats. To test this, we used an early life resource scarcity paradigm based on reducing home cage bedding during postnatal days (PND) 2-9 and assessed physical landmarks by measuring weight gain, incisor presence, fur development, and eye opening. We also evaluated the impact of early life scarcity-adversity on developmental reflexes by measuringsurface righting and grasp reflexes, negative geotaxis, cliff avoidance, bar holding, and auditory startle. Early life scarcity-adversity resulted in earlier complete lower incisor presence in males (PND 6), impaired surface righting(PND 6) and grasp reflexes (PND 8) in both sexes, and impaired cliff avoidance responses in females (PND 12). These results extend previous research examining the effects of ELA on developing male and female rodents by showing that it negatively impacts a subset of physical landmarks and developmental reflexes in a sex-dependent manner.

Acute and sub-acute toxicity of ethanol leaf extract from Acrostichum aureum in rats

Acrostichum aureum L. (A.aureum) is a medicinal plant that has anti-cancer, anti-inflammatory, and anti-bacterial activities and has been widely used traditionally in the treatment of many diseases. However, there is a dearth of information on the plant's safety. The present investigation was carried out to evaluate the acute and sub-acute toxicity of ethanol leaf extract of A. aureum (ELAA) in female Sprague Dawley (SD) rats. Oral acute toxicity was studied in female SD rats administered a single dose of 5000 mg kg-1 body weight ELAA. The sub-acute toxicity evaluation was also conducted orally with 100, 200, 500, and 750 mg kg-1 body weight of ELAA for 28 days in female SD rats. The impact of sub-acute treatment on body weight, gross histology, relative organ weight, urinalysis, hematology, plasma biochemistry, and histopathology was assessed following treatment. The ELAA did not cause death or signs of toxicity after acute treatment. Similarly, all the parameters evaluated during acute and sub-acute administration of ELAA did not significantly differ from the control. Therefore, the median lethal dose (LD50) of the ethanol extract of Acrostichum aureum is greater than 5000 mg kg-1 body weight. Its oral sub-acute administration is also non-toxic and safe at the tested doses.