Adipose tissue plasticity mediated by the counterregulatory axis of the renin-angiotensin system: Role of Mas and MrgD receptors.

The renin-angiotensin system (RAS) is an endocrine system composed of two main axes: the classical and the counterregulatory, very often displaying opposing effects. The classical axis, primarily mediated by angiotensin receptors type 1 (AT1R), is linked to obesity-associated metabolic effects. On the other hand, the counterregulatory axis appears to exert antiobesity effects through the activation of two receptors, the G protein-coupled receptor (MasR) and Mas-related receptor type D (MrgD). The local RAS in adipose organ has prompted extensive research into white adipose tissue and brown adipose tissue (BAT), with a key role in regulating the cellular and metabolic plasticity of these tissues. The MasR activation favors the brown plasticity signature in the adipose organ by improve the thermogenesis, adipogenesis, and lipolysis, decrease the inflammatory state, and overall energy homeostasis. The MrgD metabolic effects are related to the maintenance of BAT functionality, but the signaling remains unexplored. This review provides a summary of RAS counterregulatory actions triggered by Mas and MrgD receptors on adipose tissue plasticity. Focus on the effects related to the morphology and function of adipose tissue, especially from animal studies, will be given targeting new avenues for treatment of obesity-associated metabolic effects.

Obesity-induced skeletal muscle remodeling: A comparative analysis of exercise training and ACE-inhibitory drug in male mice.

Obesity over-activates the classical arm of the renin-angiotensin system (RAS), impairing skeletal muscle remodeling. We aimed to compare the effect of exercise training and enalapril, an angiotensin-converting enzyme inhibitor, on RAS modulation in the skeletal muscle of obese animals. Thus, we divided C57BL/6 mice into two groups: standard chow (SC) and high-fat (HF) diet for 16 weeks. At the eighth week, the HF-fed animals were divided into four subgroups-sedentary (HF), treated with enalapril (HF-E), exercise training protocol (HF-T), and combined interventions (HF-ET). After 8 weeks of treatment, we evaluated body mass and index (BMI), body composition, exercise capacity, muscle morphology, and skeletal muscle molecular markers. All interventions resulted in lower BMI and attenuation of overactivation in the classical arm, while favoring the B2R in the bradykinin receptors profile. This was associated with reduced apoptosis markers in obese skeletal muscles. The HF-T group showed an increase in muscle mass and expression of biosynthesis markers and a reduction in expression of degradation markers and muscle fiber atrophy due to obesity. These findings suggest that the combination intervention did not have a synergistic effect against obesity-induced muscle remodeling. Additionally, the use of enalapril impaired muscle's physiological adaptations to exercise training.

ER stress improvement by aerobic training or enalapril differently ameliorates pathological cardiac remodeling in obese mice.

Overactivation of the classic arm of the renin-angiotensin system (RAS) is one of the main mechanisms involved in obesity-related cardiac remodeling, and a possible relationship between RAS and ER stress in the cardiovascular system have been described. Thus, the aim of this study is to evaluate if activating the protective arm of the RAS by ACE inhibition or aerobic exercise training could overturn diet-induced pathological cardiac hypertrophy by attenuating ER stress. Male C57BL/6 mice were fed a control (SC) or a high-fat diet (HF) for 16 weeks. In the 8th week, HF-fed animals were randomly divided into HF, enalapril treatment (HF-En), and aerobic exercise training (HF-Ex) groups. Body mass (BM), food and energy intake, plasma analyzes, systolic blood pressure (SBP), physical conditioning, and plasma ACE and ACE2 activity were evaluated. Cardiac morphology, and protein expression of hypertrophy, cardiac metabolism, RAS, and ER stress markers were assessed. Data presented as mean ± standard deviation and analyzed by one-way ANOVA with Holm-Sidak post-hoc. HF group had increased BM and SBP, and developed pathological concentric cardiac hypertrophy, with overactivation of the classic arm of the RAS, and higher ER stress. Both interventions reverted the increase in BM, and SBP, and favored the protective arm of the RAS. Enalapril treatment improved pathological cardiac hypertrophy with partial reversal of the concentric pattern, and slightly attenuated cardiac ER stress. In contrast, aerobic exercise training induced physiological eccentric cardiac hypertrophy, and fully diminished ER stress.

Brazil Nut-Enriched Diet Modulates Enteric Glial Cells and Gut Microbiota in an Experimental Model of Chronic Kidney Disease.

Introduction: Chronic kidney disease (CKD) promotes gut dysbiosis, and enteric glial reactivity, a feature of intestinal inflammation. Brazil nut modulated enteric glial profile in healthy animals and could modulate these cells in 5/6 nephrectomized rats.Methods: A 5/6 nephrectomy-induced CKD and Sham-operated rats were divided as follows: CKD and Sham received a standard diet and CKD-BN and Sham-BN received a 5% Brazil nut enriched-diet. The protein content of glial fibrillary acid protein (GFAP), enteric glial marker, and GPx protein content and activity were assessed in the colon. The major phyla of gut microbiota were assessed.Results: CKD-BN group presented a decrease in GFAP content (p = 0.0001). The CKD-BN group modulated the abundance of Firmicutes, increasing its proportion compared to the CKD group. The CKD-BN group showed increased GPx activity in the colon (p = 0.0192), despite no significant difference in protein content.Conclusion: Brazil nut-enriched diet consumption decreased enteric glial reactivity and modulated gut microbiota in the CKD experimental model.

Effects of Probiotic-Enriched Minas Cheese (Lactobacillus acidophilus La-05) on Cardiovascular Parameters in 5/6 Nephrectomized Rats.

Dairy foods have become an interest in chronic kidney disease (CKD) due to their nutritional profile, which makes them a good substrate for probiotics incorporation. This study evaluated the effect of probiotic-enriched Minas cheese with Lactobacillus acidophilus La-05 in an experimental rat model for CKD on cardiac, inflammatory, and oxidative stress parameters. Male Wistar rats were divided into 4 groups (n = 7/group): 5/6 nephrectomy + conventional Minas cheese (NxC); 5/6 nephrectomy + probiotic Minas cheese (NxPC); Sham + conventional Minas cheese (ShamC); Sham + probiotic Minas cheese (ShamPC). Offering 20 g/day of Minas cheese with Lact. acidophilus La-05 (108-109 log CFU/g) for 6 weeks. The cardiomyocyte diameter was determined. Superoxide dismutase (SOD) activity in plasma, heart, kidney, and colon tissue was performed. At the end of supplementation, no significant changes in lipid profile and renal parameters were found. The NxPC group showed a decrease in cardiomyocyte diameter compared to the NxC group (16.99 ± 0.85 vs. 19.05 ± 0.56 µm, p = 0.0162); also they showed reduced plasmatic SOD activity (502.8 ± 49.12 vs. 599.4 ± 94.69 U/mL, p < 0.0001). In summary, probiotic-enriched Minas cheese (Lact. acidophilus La-05) consumption suggests a promisor cardioprotective effect and was able to downregulate SOD activity in a rat model of CKD.

Environmental Endocrinology: Parabens Hazardous Effects on Hypothalamic-Pituitary-Thyroid Axis.

Parabens are classified as endocrine-disrupting chemicals (EDCs) capable of interfering with the normal functioning of the thyroid, affecting the proper regulation of the biosynthesis of thyroid hormones (THs), which is controlled by the hypothalamic-pituitary-thyroid axis (HPT). Given the crucial role of these hormones in health and the growing evidence of diseases related to thyroid dysfunction, this review looks at the effects of paraben exposure on the thyroid. In this study, we considered research carried out in vitro and in vivo and epidemiological studies published between 1951 and 2023, which demonstrated an association between exposure to parabens and dysfunctions of the HPT axis. In humans, exposure to parabens increases thyroid-stimulating hormone (TSH) levels, while exposure decreases TSH levels in rodents. The effects on THs levels are also poorly described, as well as peripheral metabolism. Regardless, recent studies have shown different actions between different subtypes of parabens on the HPT axis, which allows us to speculate that the mechanism of action of these parabens is different. Furthermore, studies of exposure to parabens are more evident in women than in men. Therefore, future studies are needed to clarify the effects of exposure to parabens and their mechanisms of action on this axis.

Potential role of endoplasmic reticulum stress in the pathophysiology of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is an endocrine disorder that affects million women worldwide, presenting a complex pathophysiology that has not been fully elucidated yet. Recently, it has been suggested that PCOS triggers the endoplasmic reticulum (ER) stress, thus being associated with unfolded protein response (UPR) activation. Indeed, the UPR response has been associated with several pathological conditions, including in the reproductive system. Several studies demonstrated that ovarian UPR markers are upregulated in PCOS, being associated with worst ovarian outcomes, and this was ameliorated by ER stress inhibition. In this review, we aim to summarize the main findings from previous studies covering this topic, in an attempt to clarify the potential role of ER stress and the UPR response in the pathophysiology of PCOS.

Comparison between aerobic exercise training and enalapril treatment as tools to improve diet-induced metabolic-associated fatty liver disease: Effects on endoplasmic reticulum stress markers.

AIMS: Endoplasmic reticulum (ER) stress poses a new pathological mechanism for metabolic-associated fatty liver disease (MAFLD). MAFLD treatment has encompassed renin-angiotensin system (RAS) blockers and aerobic exercise training, but their association with hepatic ER stress is not well known. Therefore, we aimed to compare the effects of hepatic RAS modulation by enalapril and/or aerobic exercise training over ER stress in MAFLD caused by a diet-induced obesity model. MAIN METHODS: C57BL/6 mice were fed a standard-chow (CON, n = 10) or a high-fat (HF, n = 40) diet for 8 weeks. HF group was then randomly divided into: HF (n = 10), HF + Enalapril (EN, n = 10), HF + Aerobic exercise training (AET, n = 10), and HF + Enalapril+Aerobic exercise training (EN + AET, n = 10) for 8 more weeks. Body mass (BM) and glucose profile were evaluated. In the liver, ACE and ACE2 activity, morphology, lipid profile, and protein expression of ER stress and metabolic markers were assessed. KEY FINDINGS: Both enalapril and aerobic exercise training provided comparable efficacy in improving diet-induced MAFLD through modulation of RAS and ER stress, but the latter was more efficient in improving ER stress, liver damage and metabolism. SIGNIFICANCE: This is the first study to evaluate pharmacological (enalapril) and non-pharmacological (aerobic exercise training) RAS modulators associated with ER stress in a diet-induced MAFLD model.

Supplementation of diet with Brazil nut modulates body composition, bone parameters, and lipid peroxidation in Wistar rats.

Oxidative stress, adipose tissue, and bone compartments can be disturbed in chronic diseases. Non-pharmacological strategies, such as Brazil nuts (BNs), can improve these parameters. This study evaluated the effects of BN supplementation at different concentrations on body composition, lipid profile, and peroxidation in healthy rats. Male Wistar rats were divided into three groups: control (CT), Brazil nut 5% (BN5), and Brazil nut 10% (BN10) groups. Body composition, brown adipose tissue (BAT), plasma lipid peroxidation, and lipid profile were evaluated in the three groups. The BN5 group showed an improvement in all bone parameters compared with that of the CT group (p  < .0001). The BN5 and BN10 groups showed reduced plasma lipid peroxidation compared with that of the CT group (p = .0009), whereas the BN10 group presented lower BAT lipid peroxidation than that of the other groups (p = .01). High-density lipoprotein-cholesterol (HDL-c) levels were higher in the BN5 group than in the CT group (p = .01). Conclusively, the use of BNs in a controlled manner promoted improvement in bone parameters, HDL-c levels, and lipid peroxidation in healthy rats. PRACTICAL APPLICATIONS: Nuts has been included in the diet because of their versatility, acceptance, and easy access. Among them, Brazil nut (BN) is considered one of the major known food sources of selenium as well as a source of fibers, unsaturated fatty acids, and phenolic compounds. Studies have shown that BN supplementation is effective in reducing oxidative stress, inflammation, lipid peroxidation, and selenium deficiency when used as a non-pharmacological strategy in experimental models of chronic diseases and in clinical trials. The present study showed that controlled administration of BN improved bone parameters, high-density lipoprotein-cholesterol levels, and lipid peroxidation in healthy rats. Therefore, BN is a promising non-pharmacological agent for the prevention of the onset of chronic non-communicable diseases.

5/6 nephrectomy affects enteric glial cells and promotes impaired antioxidant defense in the colonic neuromuscular layer.

AIMS: Chronic kidney disease (CKD) produces multiple repercussions in the gastrointestinal tract (GIT), such as alterations in motility, gut microbiota, intestinal permeability, and increased oxidative stress. However, despite enteric glial cells (EGC) having important neural and immune features in GIT physiology, their function in CKD remains unknown. The present study investigates colonic glial markers, inflammation, and antioxidant parameters in a CKD model. MAIN METHODS: A 5/6 nephrectomized rat model was used to induce CKD in rats and Sham-operated animals as a control to suppress. Biochemical measures in plasma and neuromuscular layer such as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity were carried out. Kidney histopathology was evaluated. Colon morphology analysis and glial fibrillary acid protein (GFAP), connexin-43 (Cx43), nuclear factor-kappa B (NF-κB) p65, and GPx protein expression were performed. KEY FINDINGS: The CKD group exhibited dilated tubules and tubulointerstitial fibrosis in the reminiscent kidney (p = 0.0002). CKD rats showed higher SOD activity (p = 0.004) in plasma, with no differences in neuromuscular layer (p = 0.9833). However, GPx activity was decreased in the CKD group in plasma (p = 0.013) and neuromuscular layer (p = 0.0338). Morphological analysis revealed alterations in colonic morphometry with inflammatory foci in the submucosal layer and neuromuscular layer straightness in CKD rats (p = 0.0291). In addition, GFAP, Cx43, NF-κBp65 protein expression were increased, and GPx decreased in the neuromuscular layer of the CKD group (p < 0.05). SIGNIFICANCE: CKD animals present alterations in colonic cytoarchitecture and decreased layer thickness. Moreover, CKD affects the enteric glial network of the neuromuscular layer, associated with decreased antioxidant activity and inflammation.

Renin-angiotensin system modulation through enalapril and/or exercise training improves visceral adiposity in obese mice.

INTRODUCTION: Obesity-related metabolic diseases occur as a result of disruptions in white adipose tissue (WAT) plasticity, especially through visceral fat accumulation and adipocyte hypertrophy. This study aimed to evaluate the impact of renin-angiotensin system (RAS) and bradykinin receptors modulation by enalapril treatment and/or exercise training on WAT morphology and related deleterious outcomes. METHODS: Male C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At the 8th week, HF-fed animals were divided into sedentary (HF), enalapril treatment (HF-E), exercise training (HF-T), and enalapril treatment plus exercise training (HF-ET) groups. Following the experimental protocol, body mass gain, adiposity index, insulin resistance, visceral WAT morphometry, renin-angiotensin system, and bradykinin receptors were evaluated. RESULTS: The HF group displayed increased adiposity, larger visceral fat mass, and adipocyte hypertrophy, which was accompanied by insulin resistance, overactivation of Ang II/AT1R arm, and favoring of B1R in bradykinin receptors profile. All interventions ameliorated visceral adiposity and related outcomes by favoring the Ang 1-7/MasR arm and the B2R expression in B1R/B2R ratio. However, combined therapy additively reduced Ang II/Ang 1-7 ratio. CONCLUSION: Our results suggest that Ang 1-7/MasR arm and B2R activation might be relevant targets in the treatment of visceral obesity.

Impact of Brazil Nut (Bertholletia excelsa, H.B.K.) Supplementation on Body Composition, Blood Pressure, and the Vascular Reactivity of Wistar Rats When Submitted to a Hypersodium Diet.

Introdution: Endothelium integrity is a key that maintains vascular homeostasis but it can suffer irreversible damage by blood pressure changes, reflecting an imbalance in the maintenance of vascular homeostasis.Objective: The aim of this study was to investigate the impact of Brazil nut (Bertholletia excelsa, H.B.K.) (BN) supplementation (10% in chow, wt/wt) on the vascular reactivity of Wistar rats during chronic exposure to a sodium overload (1% in water).Methods: First, male Wistar rats were allocated into two groups: Control Group (CG) and the Hypersodic Group (HG) for 4 weeks. Afterward, the CG was divided into the Brazil Nut Group (BNG) and the HG Group into the Hypersodic Brazil Nut Group (HBNG) for a further 8 weeks, totaling 4 groups. Blood pressure was measured during the protocol. At the end of the protocol, the vascular reactivity procedure was performed. Glucose, lipid profile, lipid peroxidation, and platelet aggregation were analyzed in the serum. Body composition was determined by the carcass technique.Results: The groups that were supplemented with the BN chow presented less body mass gain and body fat mass, together with lower serum glucose levels. The HG Group presented an increase in blood pressure and a higher platelet aggregation, while the BN supplementation was able to blunt this effect. The HG Group also showed an increase in contractile response that was phenylephrine-induced and a decrease in maximum relaxation that was acetylcholine-induced when compared to the other groups.Conclusion: The BN supplementation was able to prevent an impaired vascular function in the early stages of arterial hypertension, while also improving body composition, serum glucose, and platelet aggregation.

Evaluation of the effects produced by subacute tributyltin administration on vascular reactivity of male wistar rats.

Tributyltin chloride (TBT) is an organotin compound widely used in several high biocides for agroindustrial applications, such as fungicides, and marine antifouling paints leading to endocrine disrupting actions, such as imposex development in mollusks. In female rats, TBT has been shown to promote ovarian dysfunction, reduction of estrogen protective effect in the vascular morphophysiology, at least in part by oxidative stress consequences. Estrogen causes coronary endothelium-dependent and independent vasodilation. However, the TBT effects on cardiovascular system of male rats are not fully understood. The aim of this study was to evaluate the effects of subacute TBT exposure in aorta vascular reactivity from male wistar rats. Rats were randomly divided into three groups: control (C), TBT 500 ng/kg/day and TBT 1000 ng/kg/day. TBT was administered daily for 30 days by oral gavage. We found that TBT exposure enhanced testosterone serum levels and it was also observed obesogenic properties. TBT exposure evoked an increase in endothelium-dependent and independent phenylephrine-induced contraction, associated to an inhibition in eNOS activity. On the other hand, it was observed an enhancement of iNOS and NF-kB protein expression. We also observed an increase in oxidative stress parameters, such as superoxide dismutase (SOD) and catalase expression, and also an increase in malondialdehyde production. Finally, TBT exposure produced aortic intima-media thickness. Taken together, these data suggest a potential cardiovascular toxicological effect after subacute TBT exposure in male rats.

Crosstalk between the renin-angiotensin system and the endoplasmic reticulum stress in the cardiovascular system: Lessons learned so far.

The renin-angiotensin (Ang) system (RAS) is a complex hormonal system present locally in several tissues such as cardiovascular organs. RAS deregulation through overactivation of the classical arm [Ang-converting enzyme (ACE)/Ang-II/Ang type 1 receptor (AT1R)] has been linked to the development of cardiovascular diseases and activation of endoplasmic reticulum (ER) stress pathways. The ER stress is a condition that, if unresolved, might lead to heart failure, atherosclerosis, hypertension, and endothelial dysfunction. Accumulated evidence has shown that the RAS modulates the UPR activation. Several studies reported increased ER stress markers in response to Ang-II treatment, in both in vivo and in vitro models. Evidence has also pointed that targeting the RAS classical arm through RAS blockers, gene silencing or genetic models leads to lower levels of ER stress markers. Few studies demonstrated protective effects of the counter-regulatory arm (ACE-2/Ang-(1-7)/Mas receptor) over ER stress. However, the crosstalk mechanisms between the arms of the RAS and ER stress remain unclear. In this review, we sought to explore the classical arm of the RAS as a key mechanism in UPR activation and to suggest a possible protective role of the counter-regulatory arm in mitigating ER stress.

Modulation of cardiac renin-angiotensin system, redox status and inflammatory profile by different volumes of aerobic exercise training in obese rats.

Overactivation of the classical arm of the renin-angiotensin (Ang) system (RAS) occurs during inflammation, oxidative stress and obesity-induced cardiomyopathy. The activation of the protective arm of RAS may act to counterbalance the deleterious effects of the classical RAS. Although aerobic exercise training (AET) shifts the balance of the RAS towards the protective arm, little is known about the molecular adaptations to different volumes of AET. The aim of this study was to evaluate the impact of AET volume on the modulation of RAS, as well as on cardiac biomarkers of oxidative stress and inflammation, in a diet-induced obesity model. Male Wistar rats were fed either control (CON) or high fat (HF) diet for 32 weeks. At week 20, HF group was subdivided into sedentary, low (LEV, 150 min/week) or high (HEV, 300 min/week) exercise volume. After 12 weeks of exercise, body mass gain, systolic blood pressure and heart rate were evaluated, as well as RAS, oxidative stress and inflammation in the heart. Body mass gain, systolic blood pressure and heart rate were higher in HF group when compared with SC group. Both trained groups restored systolic blood pressure and heart rate, but only HEV reduced body mass gain. Regarding the cardiac RAS, the HF group exhibited favoring of the classical arm and both trained groups shifted the balance towards the counterregulatory protective arm. The HF group had higher B1R expression and lower B2R expression than the control group, and B2R expression was reverted in both trained groups. The HF group also presented oxidative stress. The LEV and HEV groups improved the cardiac redox status by reducing Nox 2 and nitrotyrosine expression, but only the LEV group was able to increase the antioxidant defense by increasing Nrf2 signaling. While the HF group presented higher TNF-α, IL-6 and NFκB expression, and lower IL-10 expression, than the SC group, both training protocols improved the inflammatory profile. Although both trained groups improved the deleterious changes related to obesity cardiomyopathy, it is clear that the molecular mechanisms differ between them. Our results suggest that different exercise volumes might reach different molecular targets, and this could be a relevant factor when using exercise to manage obesity.

Effects of short-term high-intensity interval and continuous exercise training on body composition and cardiac function in obese sarcopenic rats.

AIM: We investigated the effects of high-intensity interval and continuous short-term exercise on body composition and cardiac function after myocardial ischemia-reperfusion injury (IRI) in obese rats. METHODS: Rats fed with a standard chow diet (SC) or high-fat diet (HFD) for 20 weeks underwent systolic blood pressure (SBP), glycemia and dual-energy X-ray absorptiometry analyses. Then, animals fed with HFD were subdivided into three groups: sedentary (HFD-SED); moderate-intensity continuous training (HFD-MICT); and high-intensity interval training (HFD-HIIT). Exercised groups underwent four isocaloric aerobic exercise sessions, in which HFD-MICT maintained the intensity continuously and HFD-HIIT alternated it. After exercise sessions, all groups underwent global IRI and myocardial infarct size (IS) was determined histologically. Fat and muscle mass were weighted, and protein levels involved in muscle metabolism were assessed in skeletal muscle. RESULTS: HFD-fed versus SC-fed rats reduced lean body mass by 31% (P < 0.001), while SBP, glycemia and body fat percentage were increased by 10% (P = 0.04), 30% (P = 0.006) and 54% (P < 0.001); respectively. HFD-induced muscle atrophy was restored in exercised groups, as only HFD-SED presented lower gastrocnemius (32%; P = 0.001) and quadriceps mass (62%; P < 0.001) than SC. PGC1-α expression was 2.7-fold higher in HFD-HIIT versus HFD-SED (P = 0.04), whereas HFD-HIIT and HFD-MICT exhibited 1.7-fold increase in p-mTORSer2481 levels compared to HFD-SED (P = 0.04). Although no difference was detected among groups for IS (P = 0.30), only HFD-HIIT preserved left-ventricle developed pressure after IRI (+0.7 mmHg; P = 0.9). SIGNIFICANCE: Short-term exercise, continuous or HIIT, restored HFD-induced muscle atrophy and increased mTOR expression, but only HIIT maintained myocardial contractility following IRI in obese animals.

Efeito da técnica de coleta e do estágio do ciclo estral na recuperação de oócitos de boa qualidade em felinos e caninos domésticos / The effect of recovery technique and stage of estrous cycle on the recoveryof good quality oocytes in domestic felines and canines

A obtenção de oócitos de boa qualidade é essencial para o sucesso de diversas biotécnicas reprodutivas. Objetivou-se determinar o efeito de duas técnicas na recuperação de oócitos de boa qualidade em gatas e cadelas em diferentes estágios reprodutivos. Foram utilizados 43 pares de ovários de gata e 35 de cadela após realização da ovariosalpingohisterectomia eletiva. A fase do ciclo estral foi classificada em inativa, folicular ou luteal. Os ovários da fase folicular foram divididos em três grupos: PUN) punção dos folículos com agulha; PUN+FAT) fatiamento do mesmo ovário já puncionado; e FAT) fatiamento do segundo ovário. Os ovários das fêmeas em fase luteal e inativa foram submetidos ao FAT. Foram obtidos no total 974 oócitos (~23/animal) nas fêmeas felinas e 940 (~27/animal) nas caninas. O fatiamento recuperou número superior (P0,05) entre as técnicas de coleta na qualidade de estruturas recuperadas. A quantidade de oócitos recuperados em cada fase foi similar (P>0,05). Contudo, a fase inativa foi superior à luteal (P<0,05) e semelhante à folicular na quantidade de oócitos de boa qualidade em gatas e não houve diferença em cadelas. Conclui-se que o fatiamento recupera maior quantidade de oócitos, não influenciando em sua qualidade. As fases inativa e folicular recuperam maior quantidade de oócitos de boa qualidade em gatas e não afetam a recuperação em cadelas. Portanto, para otimizar o uso das biotecnologias, deve-se levar em consideração o estágio do ciclo estral em fêmeas felinas e a técnica de coleta utilizada na recuperação de oócitos.

The recovery of good quality oocytes is essential for the success of various reproductive biotechniques. The aim of this study was to determine the effect of two techniques on the recovery of good quality oocytes in queens and bitches at different reproductive stages. A total of 43 pairs of ovaries of queens and 35 of bitches after elective ovariosalpingohisterectomy were performed. The estrous cycle phase was classified as inactive, follicular or luteal. The ovaries of the follicular phase were allocated into three groups: PUN) puncture of the follicles with a needle; PUN + SLI) slicing of the same ovary already punctured; and SLI) slicing of the second ovary. The ovaries of luteal and inactive females were submitted to SLI. A total of 974 oocytes (~23/animal) were obtained in feline females and 940 (~27/animal) in canines females. The SLI technique recovered superior number (P0.05) between the collection techniques in the quality of recovered structures. The number of oocytes recovered in each phase was similar (P>0.05). However, the inactive phase was higher than luteal (P<0.05) and similar to the follicular phase in the quantity of good-quality oocytes in queens and there was no difference in bitches. In conclusion, it is preferable to perform the slicing technique to recover more oocytes in both species. Moreover, in queens it is possible to obtain good quality oocytes in the inactive phase and in bitches the estrous cycle phase does not influence the quality.

Efeito da técnica de coleta e do estágio do ciclo estral na recuperação de oócitos de boa qualidade em felinos e caninos domésticos / The effect of recovery technique and stage of estrous cycle on the recovery of good quality oocytes in domestic felines and canines

A obtenção de oócitos de boa qualidade é essencial para o sucesso de diversas biotécnicas reprodutivas. Objetivou-se determinar o efeito de duas técnicas na recuperação de oócitos de boa qualidade em gatas e cadelas em diferentes estágios reprodutivos. Foram utilizados 43 pares de ovários de gata e 35 de cadela após realização da ovariosalpingohisterectomia eletiva. A fase do ciclo estral foi classificada em inativa, folicular ou luteal. Os ovários da fase folicular foram divididos em três grupos: PUN) punção dos folículos com agulha; PUN+FAT) fatiamento do mesmo ovário já puncionado; e FAT) fatiamento do segundo ovário. Os ovários das fêmeas em fase luteal e inativa foram submetidos ao FAT. Foram obtidos no total 974 oócitos (~23/animal) nas fêmeas felinas e 940 (~27/animal) nas caninas. O fatiamento recuperou número superior (P<0,05) de oócitos. Não houve diferença (P>0,05) entre as técnicas de coleta na qualidade de estruturas recuperadas. A quantidade de oócitos recuperados em cada fase foi similar (P>0,05). Contudo, a fase inativa foi superior à luteal (P<0,05) e semelhante à folicular na quantidade de oócitos de boa qualidade em gatas e não houve diferença em cadelas. Conclui-se que o fatiamento recupera maior quantidade de oócitos, não influenciando em sua qualidade. As fases inativa e folicular recuperam maior quantidade de oócitos de boa qualidade em gatas e não afetam a recuperação em cadelas. Portanto, para otimizar o uso das biotecnologias, deve-se levar em consideração o estágio do ciclo estral em fêmeas felinas e a técnica de coleta utilizada na recuperação de oócitos.

The recovery of good quality oocytes is essential for the success of various reproductive biotechniques. The aim of this study was to determine the effect of two techniques on the recovery of good quality oocytes in queens and bitches at different reproductive stages. A total of 43 pairs of ovaries of queens and 35 of bitches after elective ovariosalpingohisterectomy were performed. The estrous cycle phase was classified as inactive, follicular or luteal. The ovaries of the follicular phase were allocated into three groups: PUN) puncture of the follicles with a needle; PUN + SLI) slicing of the same ovary already punctured; and SLI) slicing of the second ovary. The ovaries of luteal and inactive females were submitted to SLI. A total of 974 oocytes (~23/animal) were obtained in feline females and 940 (~27/animal) in canines females. The SLI technique recovered superior number (P<0.05) of oocytes. There was no difference (P>0.05) between the collection techniques in the quality of recovered structures. The number of oocytes recovered in each phase was similar (P>0.05). However, the inactive phase was higher than luteal (P<0.05) and similar to the follicular phase in the quantity of good-quality oocytes in queens and there was no difference in bitches. In conclusion, it is preferable to perform the slicing technique to recover more oocytes in both species. Moreover, in queens it is possible to obtain good quality oocytes in the inactive phase and in bitches the estrous cycle phase does not influence the quality.

Exercise-induced cardiac opioid system activation attenuates apoptosis pathway in obese rats.

AIM: To compare the effect of 150 min vs. 300 min of weekly moderate intensity exercise training on the activation of the opioid system and apoptosis in the hearts of a diet-induced obesity model. METHODS: Male Wistar rats were fed with either control (CON) or high fat (HF) diet for 32 weeks. At the 20th week, HF group was subdivided into sedentary, low (LEV, 150 min·week-1) or high (HEV, 300 min·week-1) exercise volume. After 12 weeks of exercise, body mass gain, adiposity index, systolic blood pressure, cardiac morphometry, apoptosis biomarkers and opioid system expression were evaluated. RESULTS: Sedentary animals fed with HF presented pathological cardiac hypertrophy and higher body mass gain, systolic blood pressure and adiposity index than control group. Both exercise volumes induced physiological cardiac hypertrophy, restored systolic blood pressure and improved adiposity index, but only 300 min·week-1 reduced body mass gain. HF group exhibited lower proenkephalin, PI3K, ERK and GSK-3ß expression, and greater activated caspase-3 expression than control group. Compared to HF, no changes in the cardiac opioid system were observed in the 150 min·week-1 of exercise training, while 300 min·week-1 showed greater proenkephalin, DOR, KOR, MOR, Akt, ERK and GSK-3ß expression, and lower activated caspase-3 expression. CONCLUSION: 300 min·week-1 of exercise training triggered opioid system activation and provided greater cardioprotection against obesity than 150 min·week-1. Our findings provide translational aspect with clinical relevance about the critical dose of exercise training necessary to reduce cardiovascular risk factors caused by obesity.