Extracellular vesicles derived from bovine adipose-derived mesenchymal stromal cells enhance in vitro embryo production from lesioned ovaries.

BACKGROUND AND AIMS: Ovum pick-up (OPU) is an intrinsic step of in vitro fertilization procedures. Nevertheless, it can cause ovarian lesions and compromise female fertility in bovines. Recently, we have shown that intraovarian injection of adipose-derived mesenchymal stromal cells (AD-MSCs) effectively preserves ovarian function in bovines. Given that MSC-derived extracellular vesicles (MSC-EVs) have been shown to recapitulate several therapeutic effects attributed to AD-MSCs and that they present logistic and regulatory advantages compared to AD-MSCs, we tested whether MSC-EVs would also be useful to treat OPU-induced lesions. METHODS: MSC-EVs were isolated from the secretome of bovine AD-MSCs, using ultrafiltration (UF) and ultracentrifugation methods. The MSC-EVs were characterized according to concentration and mean particle size, morphology, protein concentration and EV markers, miRNA, mRNA, long noncoding RNA profile, total RNA yield and potential for induction of the proliferation and migration of bovine ovarian stromal cells. We then investigated whether intraovarian injection of MSC-EVs obtained by UF would reduce the negative effects of acute OPU-induced ovarian lesions in bovines. To do so, 20 animals were divided into 4 experimental groups (n = 5), submitted to 4 OPU cycles and different experimental treatments including vehicle only (G1), MSC-EVs produced by 7.5 × 106 AD-MSCs (G2), MSC-EVs produced by 2.5 × 106 AD-MSCs (G3) or 3 doses of MSC-EVs produced by 2.5 × 106 AD-MSCs, injected after OPU sessions 1, 2 and 3 (G4). RESULTS: Characterization of the MSC-EVs revealed that the size of the particles was similar in the different isolation methods; however, the UF method generated a greater MSC-EV yield. MSC-EVs processed by both methods demonstrated a similar ability to promote cell migration and proliferation in ovarian stromal cells. Considering the higher yield and lower complexity of the UF method, UF-MSC-EVs were used in the in vivo experiment. We evaluated three therapeutic regimens for cows subjected to OPU, noting that the group treated with three MSC-EV injections (G4) maintained oocyte production and increased in vitro embryo production, compared to G1, which presented compromised embryo production following the OPU-induced lesions. CONCLUSIONS: MSC-EVs have beneficial effects both on the migration and proliferation of ovarian stromal cells and on the fertility of bovines with follicular puncture injury in vivo.

High-intensity aerobic training lowers blood pressure and modulates the renal renin-angiotensin system in spontaneously hypertensive rats.

Background: This study aimed to verify the effects of high-intensity aerobic training (HIAT) on BP control and renin-angiotensin system (RAS) components in renal tissue of SHR. Ten SHRs received HIAT or control for 8-weeks. At the end of the training, the SBP showed a reduction of ~ 30mmHg (p < .01) in HIAT and increased by ~ 15 mmHg in the  control group. HIAT resulted in a higher release of nitrite, IL-6, ACE2 and ATR2. These results indicated an association between BP, NO and renal RAS.Abbreviations: JAA: writing, carried out all experimental procedures, performed statistical analysis, original draft and revised manuscript DMS: data interpretation, formal analysis, writing, editing and revised manuscript BAP: carried all experimental procedures, revised manuscritpt CPCG: carried all experimental procedures, revised manuscritpt MEN: experimental procedures, revised manuscript and data interpretation RWP: drafted and revised manuscript RCA: writing, experimental procedures, revised manuscript JP: writing, data interpretation and revised manuscript OLF: writing, original draft and revised manuscript.

Comparison of Four Purification Methods on Serum Extracellular Vesicle Recovery, Size Distribution, and Proteomics.

In recent decades, the role played by extracellular vesicles in physiological and pathological processes has attracted attention. Extracellular vesicles are released by different types of cells and carry molecules that could become biomarkers for the diagnosis of diseases. Extracellular vesicles are also moldable tools for the controlled release of bioactive substances in clinical and therapeutic applications. However, one of the significant challenges when studying these exciting and versatile vesicles is the purification process, which presents significant difficulties in terms of lack of purity, yield, and reproducibility, reflected in unreliable data. Therefore, our objective in the present study was to compare the proteomic profile of serum-derived EVs purified using ExoQuick™ (Systems Biosciences), Total Isolation Kit (Life Technologies), Ultracentrifugation, and Ultrafiltration. Each technique utilized for purification has shown different concentrations and populations of purified particles. The results showed marked differences in distribution, size, and protein content, demonstrating the need to develop reproducible and reliable protocols to isolate extracellular vesicles for their clinical application.

Hallmarks of aging and immunosenescence: Connecting the dots.

Aging is a natural physiological process that features various and variable challenges, associated with loss of homeostasis within the organism, often leading to negative consequences for health. Cellular senescence occurs when cells exhaust the capacity to renew themselves and their tissue environment as the cell cycle comes to a halt. This process is influenced by genetics, metabolism and extrinsic factors. Immunosenescence, the aging of the immune system, is a result of the aging process, but can also in turn act as a secondary inducer of senescence within other tissues. This review aims to summarize the current state of knowledge regarding hallmarks of aging in relation to immunosenescence, with a focus on aging-related imbalances in the medullary environment, as well as the components of the innate and adaptive immune responses. Aging within the immune system alters its functionality, and has consequences for the person's ability to fight infections, as well as for susceptibility to chronic diseases such as cancer and cardiovascular disease. The senescence-associated secretory phenotype is described, as well as the involvement of this phenomenon in the paracrine induction of senescence in otherwise healthy cells. Inflammaging is discussed in detail, along with the comorbidities associated with this process. A knowledge of these processes is required in order to consider possible targets for the application of senotherapeutic agents - interventions with the potential to modulate the senescence process, thus prolonging the healthy lifespan of the immune system and minimizing the secondary effects of immunosenescence.

Self-Selected Pacing During a World Record Attempt in 40 Ironman-Distance Triathlons in 40 Days.

The present case study analyzed performance, pacing, and potential predictors in a self-paced world record attempt of a professional triathlete to finish 40 Ironman-distance triathlons within 40 days. Split times (i.e., swimming, cycling, running) and overall times, body weight, daily highest temperature, wind speed, energy expenditure, mean heart rate, and sleeping time were recorded. Non-linear regressions were applied to investigate changes in split and overall times across days. Multivariate regression analyses were performed to test which variables showed the greatest influence on the dependent variables cycling, running and overall time. The athlete completed the 40×Ironman distances in a total time of 444:22 h:min. He spent 50:26 h:min in swimming, 245:37 h:min in cycling, 137:17 h:min in running and 11:02 h:min in transition times. Swimming and cycling times became slower across days, whereas running times got faster until the 20th day and, thereafter, became slower until the 40th day. Overall times got slower until the 15th day, became faster to 31st, and started then to get slower until the end. Wind speed, previous day's race time and average heart race during cycling were significant independent variables influencing cycling time. Body weight and average heart rate during running were significant independent variables influencing running performance. Cycling performance, running performance, and body weight were significant independent variables influencing overall time. In summary, running time was influenced by body weight, cycling by wind speed, and overall time by both running and cycling performances.

Genomic characterization and prognostication applied to a Brazilian cohort of patients with myelofibrosis.

Genomic characterization of patients with myeloproliferative neoplasms (MPN) may lead to better diagnostic classification, prognostic assessment, and treatment decisions. These goals are particularly important in myelofibrosis (MF). We performed target Next Generation Sequencing for a panel of 255 genes and Chromosome Microarray Analysis (CMA) in 27 patients with MF. Patients were classified according to genomic findings and we compared the performance of a personalized prognostication system with IPSS, MIPSS70 and MIPSS70 + v2. Twenty-six patients presented mutations: 11.1% had single driver mutations in either JAK2, CALR or MPL; 85.2% had mutations in non-restricted genes (median: 2 per patient). CMA was abnormal in 91.7% of the 24 cases with available data. Copy-Number-Neutral Loss-of-Heterozygosity was the most common finding (66.7%). Del13q was the most frequent copy number variation, and we could define a 2.4 Mb minimally affected region encompassing RB1, SUCLA2 and CLLS2 loci. The largest genomic subgroup consisted of patients with mutations in genes involved with chromatin organization and splicing control (40.7%) and the personalized system showed better concordance and accuracy than the other prognostic systems. Comprehensive genomic characterization reveals the striking genetic complexity of MF and, when combined with clinical data, led, in our cohort, to better prognostication performance.

Assessment of the Immunosuppressive Potential of INF-γ Licensed Adipose Mesenchymal Stem Cells, Their Secretome and Extracellular Vesicles.

There is an active search for the ideal strategy to potentialize the effects of Mesenchymal Stem-Cells (MSCs) over the immune system. Also, part of the scientific community is seeking to elucidate the therapeutic potential of MSCs secretome and its extracellular vesicles (EVs), in order to avoid the complexity of a cellular therapy. Here, we investigate the effects of human adipose MSCs (AMSCs) licensing with INF-γ and TLR3 agonist over AMSCs proliferation, migration, as well as the immunomodulatory function. Furthermore, we evaluated how the licensing of AMSCs affected the immunomodulatory function of AMSC derived-secretome, including their EVs. INF-γ licensed-AMSCs presented an elevated expression of indoleamine 2,3-dioxygenase (IDO), accompanied by increased ICAM-1, as well as a higher immunosuppressive potential, compared to unlicensed AMSCs. Interestingly, the conditioned medium obtained from INF-γ licensed-AMSCs also revealed a slightly superior immunosuppressive potential, compared to other licensing strategies. Therefore, unlicensed and INF-γ licensed-AMSCs groups were used to isolate EVs. Interestingly, EVs isolated from both groups displayed similar capacity to inhibit T-cell proliferation. EVs isolated from both groups shared similar TGF-ß and Galectin-1 mRNA content but only EVs derived from INF-γ licensed-AMSCs expressed IDO mRNA. In summary, we demonstrated that INF-γ licensing of AMSCs provides an immunosuppressive advantage both from a cell-cell contact-dependent perspective, as well as in a cell-free context. Interestingly, EVs derived from unlicensed and INF-γ licensed-AMSCs have similar ability to control activated T-cell proliferation. These results contribute towards the development of new strategies to control the immune response based on AMSCs or their derived products.

LL-37 treatment on human peripheral blood mononuclear cells modulates immune response and promotes regulatory T-cells generation.

LL-37 is a host-defense peptide (HDP) and exerts a broad spectrum of microbicidal activity against bacteria, fungi, and viral pathogens. This peptide also interacts with human cells and influences their behavior, promoting angiogenesis, wound healing, immunomodulation, and affecting apoptosis. Lately, significant advances have been achieved regarding the elucidation of underlying mechanisms related to LL-37 effects over neutrophil and monocytes. However, how T-cells respond to LL-37 stimulation is still largely unknown. Here, we used flow cytometry to evaluate the effects of LL-37 over peripheral blood mononuclear cells (PBMCs) viability, T-cell proliferation, T-cell activation, as well as the generation of regulatory T-cells (Tregs). Those aspects were assessed both in immune homeostatic and inflammatory milieu. Furthermore, we investigated the transcript levels of the inflammatory factors INF-γ, TNF-ɑ, and TGF-ß in these conditions. Interestingly, our data revealed that the treatment of PBMCs with LL-37 enhanced the viability of these cells and exerted wide effects over T cell response. Upon activation, LL-37 treated T-cells presented lower proliferation and also increased generation of Tregs. Finally, while non-stimulated cells increased the expression of inflammatory factors when treated with LL-37, activated cells treated with LL-37 presented a decreased production of the same inflammatory mediators. These results are important for the immunotherapy field, and indicate that the use of LL-37 must be carefully evaluated in both homeostatic and inflammatory scenarios, since the microenvironment clearly plays a crucial role in determining how T-cells respond to LL-37.

Small de novo CNVs as biomarkers of parental exposure to low doses of ionizing radiation of caesium-137.

The radiological accident in Goiania in 1987 caused a trail of human contamination, animal, plant and environmental by a radionuclide. Exposure to ionizing radiation results in different types of DNA lesions. The mutagenic effects of ionizing radiation on the germline are special concern because they can endures for several generations, leading to an increase in the rate of mutations in children of irradiated parents. Thus, to evaluate the biological mechanisms of ionizing radiation in somatic and germline cells, with consequent determination of the rate mutations, is extremely important for the estimation of genetic risks. Recently it was established that Chromosomal Microarray Analysis is an important tool for detecting wide spectra of gains or losses in the human genome. Here we present the results of the effect of accidental exposure to low doses of ionizing radiation on the formation of CNVs in the progeny of a human population accidentally exposed to Caesium-137 during the radiological accident in Goiânia, Brazil.

Lack of association between vitamin D receptor genotypes and haplotypes with fat-free mass in postmenopausal Brazilian women.

The relationship between vitamin D receptor (VDR) ApaI, CDX2, BsmI, FokI, and TaqI polymorphisms and fat-free mass (FFM) were examined in 191 postmenopausal Brazilian women (mean age 67.87 +/- 5.22 years). Participants underwent FFM measurements by dual-energy x-ray absorptiometry (DEXA). Whole-blood-extracted genomic DNA was genotyped to the aforementioned polymorphisms and to ancestry-informative markers through minisequencing, using the SNaPshot Multiplex System. Association between VDR polymorphisms and FFM variables was assessed by analysis of covariance. Haplotypes were estimated, and regression-based, haplotype-specific association tests were carried out with the studied phenotypes. No departure from Hardy-Weinberg equilibrium was detected for any polymorphism. None of the investigated VDR allelic variations, individually or analyzed as haplotypes, was associated with FFM phenotypes. The inclusion of individual African genomic ancestry was used as an attempt to correct for population stratification. Further studies in larger sample population are required to confirm these findings.

Association between femoral neck bone mineral density and lower limb fat-free mass in postmenopausal women.

Aging is associated with several physiological changes that lead to increased disability and mortality. Examples of these changes are deteriorations in bone and muscle tissues, referred, respectively, as osteopenia and sarcopenia. Both have been linked to multiple morbid outcomes in older adults. The main purpose of this study was to determine the association between femoral neck and trochanter bone mineral density (BMD) and lower limb non-bone fat-free mass (MM) in postmenopausal women. One hundred eighty nine postmenopausal women volunteered to participate in the study (mean age 66.92+/-5.23 yr). Subjects were divided into different groups according to lower limb MM, femoral neck, and trochanter BMD measurements using the 2-step cluster analysis. Pearson chi-square was used to analyze the correlation between the BMD and MM distributions. The 2-step cluster analysis leads to the formation of 3 groups according to the levels of lower limb MM (LMM--low values of MM, IMM--intermediate values of MM, and HMM--high values of MM), 2 groups according to the values of femoral neck BMD (LFN--low values and HFN--high values), and 3 groups for trochanter BMD (LTR--low values, ITR--intermediate values, and HTR--high values). The results of Pearson chi-square revealed a significant association between femoral neck BMD and lower limb MM, and trochanter BMD and lower limb MM, suggesting that individuals with reduced lower limb MM are prone to have decreased femoral neck and trochanter BMD. The present study supports the hypothesis of a relation between the incidence of low BMD and MM. It is recommended that dual-energy X-ray absorptiometry screening should be used to identify both BMD and MM in postmenopausal women to assess more accurately the risk of fractures and disability.

Exercise as an Effective Transgenerational Strategy to Overcome Metabolic Syndrome in the Future Generation: Are We There?

Metabolic syndrome (MetS) consist in a combination of cardiovascular risk factors including elevated blood pressure, dyslipidemia, insulin resistance, hyperglycemia and abdominal obesity. Exercise performed before, during and after pregnancy can exert positive effects to counteract MetS risk factors. Here this review aims to analyze the effects of exercise performed before (fathers and mothers) and after periconception (mothers) by using experimental models and its effects on MetS risk factors in offspring. All selected studies investigated the effects of aerobic exercise before, during and after periconception on MetS risk factors in offspring, while no studies utilizing resistance exercise were found. Exercise performed before, and after periconception exerted preventive effects in the offspring, with regards to MetS risk factors. However, more studies focusing on the dose-response of exercise before, and after periconception may reveal interesting results on MetS risk factor in offspring. Thus, the prevention from chronic degenerative diseases can be improved by mother exercise and might be associated with epigenetic mechanisms, such as DNA methylation, hPTMs (histone post translational modifications), non-coding RNAs (ex: MicroRNAs) which results phenotypic modifications by individual genome reprograming. Otherwise, results from paternal exercise are inconclusive at this time.

A novel polymorphic Alu insertion embedded in a LINE 1 retrotransposon in the human X chromosome (DXS225): identification and worldwide population study.

We describe a novel polymorphic Alu insertion (DXS225) on the human X chromosome (Xq21.3) embedded into an L1 retrotransposon. The DXS225 polymorphism was genotyped in 684 males from the CEPH Human Genome Diversity Panel. This insertion was found in all regions of the globe, suggesting that it took place before modern humans spread from Africa ca. 100,000 years ago. However, only one Amerindian population (Karitiana) showed this insertion allele, which may have been introduced by European admixture. Thus, it appears likely that the Alu insertion was absent from pre-Columbian America. Analysis of molecular variance worldwide demonstrated that 92.2% of the genetic variance was concentrated within populations. DXS225 is flanked by two microsatellites (DXS8114 and DXS1002), which are 86 kb apart and are in very strong linkage disequilibrium. The combination of a unique event polymorphism on the X chromosome in linkage disequilibrium with two rapidly evolving microsatellites should provide a useful tool for studies of human evolution.

LL-37 boosts immunosuppressive function of placenta-derived mesenchymal stromal cells.

BACKGROUND: Although promising for graft-versus-host disease (GvHD) treatment, MSC therapy still faces important challenges. For instance, increasing MSC migratory capacity as well as potentializing immune response suppression are of interest. For GvHD management, preventing opportunistic infections is also a valuable strategy, since immunocompromised patients are easy targets for infections. LL-37 is a host defense peptide (HDP) that has been deeply investigated due to its immunomodulatory function. In this scenario, the combination of MSC and LL-37 may result in a robust combination to be clinically used. METHODS: In the present study, the effects of LL-37 upon the proliferation and migratory capacity of human placenta-derived MSCs (pMSCs) were assessed by MTT and wound scratch assays. The influence of LL-37 over the immunosuppressive function of pMSCs was then investigated using CFSE cell division kit. Flow cytometry and real-time PCR were used to investigate the molecular mechanisms involved in the effects observed. RESULTS: LL-37 had no detrimental effects over MSC proliferation and viability, as assessed by MTT assay. Moreover, the peptide promoted increased migratory behavior of pMSCs and enhanced their immunomodulatory function over activated human PBMCs. Strikingly, our data shows that LL-37 treatment leads to increased TLR3 levels, as shown by flow cytometry, and to an increased expression of factors classically related to immunosuppression, namely IDO, IL-10, TGF-ß, IL-6, and IL-1ß. CONCLUSIONS: Taken together, our observations may serve as groundwork for the development of new therapeutic strategies based on the combined use of LL-37 and MSCs, which may provide patients not only with an enhanced immunosuppression regime, but also with an agent to prevent opportunistic infections.

Pro-inflammatory cytokines correlate with classical risk factors for atherosclerosis in the admixed Brazilian older women.

AIM: Measurement of inflammatory markers for risk stratification of vascular disorders has been the focus of numerous investigations worldwide, and usually reveals augmented levels of circulating cytokines/chemokines among carriers of classic risk factors for atherosclerosis. Nonetheless, this low-grade inflammatory milieu detected in aged individuals tends to be influenced by body composition. Moreover, cardiovascular risk factors have a complex genetic etiology, and disregarding the genetic heritage may produce spurious results owing to interethnic differences. In this complex scenario, our study was designed to verify the existence and strength of the association between selected mediators of systemic inflammation and classic risk factors of cardiovascular diseases (CVD). METHODS: In a sample of post-menopausal older women, correlation analyses explored the association of circulating levels of IL1α, IL1ß, IL8, IL10 and IL12 with atherosclerosis-related clinical/metabolic parameters, using age, body mass index (BMI), genetic ancestry estimates as standard correction factors. Further adjustment for use of therapeutic agents was applied when appropriate. RESULTS: Our analyses revealed association of log10-transformed IL-12 titers with VLDL-c levels (r=.192; p=.002) and with SBP (r-.185; p=.003), and of log10-transformed IL-8 titers with GLY (r=.235; p<.001). CONCLUSION: Interpretation to the results account to a possible dysregulation of the PPAR signaling pathway to explain the association of IL12 and VLDL-c, and to IL8-driven mechanisms to promote dysglycemia. No previous report sought to investigate the relationship between this set of inflammatory markers and classic risk factors for atherosclerosis correcting for the heterogeneity in genetic admixture and body composition of Brazilian post-menopausal women.

Allele frequencies data and statistic parameters for 16 STR loci-D19S433, D2S1338, CSF1PO, D16S539, D7S820, D21S11, D18S51, D13S317, D5S818, FGA, Penta E, TH01, vWA, D8S1179, TPOX, D3S1358-in the Rio de Janeiro population, Brazil.

Allele frequencies for 16 short tandem repeats (STR) loci were determined with a sample of 230-300 unrelated individuals from the population of Rio de Janeiro, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the Identifiler (Applied Biosystems) and PowerPlex 2.1 (Promega) commercial kits. It was proved that Penta E and D18S51 are the most polymorphic loci.

The exon 3 polymorphism of the growth hormone receptor is a severity-related factor for osteoporosis.

The purpose of this study was to investigate the association between the GHR exon 3 fl/d3 polymorphism and body composition traits in Brazilian cohorts of normal post-menarche adolescent girls and in post-menopausal women with and without osteoporosis. First, multiplex PCR and quantitative PCR (TaqMan) were used with 105 DNA samples from the general Brazilian population to validate the SNP rs6873545 as a surrogate marker for the GHR polymorphism. Subsequently, genotyping was carried out to evaluate associations for this polymorphism in 136 post-menarche adolescents and 175 post-menopausal women, who were evaluated for body composition traits such as bone mineral density and fat-free mass. Statistical analysis used an independent sample t test, one-way ANOVA test and post hoc Tukey HSD test. Significant values were assumed by p < 0.05. Genotyping indicated complete linkage disequilibrium between the GHR polymorphism and the SNP alleles (r(2) = 1.0). Adolescents and healthy post-menopausal women showed no genotype associations for body composition traits or osteoporosis. However, a lower total body bone mineral density was observed in fl/fl post-menopausal women with osteoporosis (p = 0.0004). These results suggest that the SNP rs6873545 can be used as a surrogate for the GHR fl/d3 polymorphism due to linkage disequilibrium in the Brazilian population and that the fl/fl genotype is a severity-related risk factor for osteoporosis, but did not appear to be associated with disease status.

Suggestive linkage to chromosome 1q for bone mineral apparent density in Brazilian sister adolescents.

OBJECTIVE: To investigate linkage to chromosome 1q and 11q region for lumbar spine, femoral neck and total body BMD and volumetric BMD in Brazilian sister adolescents aged 10-20-year-old and 57 mothers. METHODS: We evaluated 161 sister pairs (n=329) aged 10-20 years old and 57 of their mothers in this study. Physical traits and lifestyle factors were collected as covariates for lumbar spine (LS), femoral neck (FN) and total body (TB) BMD and bone mineral apparent density (BMAD). We selected nine microsatellite markers in chromosome 1q region (spanning nearly 33cM) and eight in chromosome 11q region (spanning nearly 34cM) to perform linkage analysis. RESULTS: The highest LOD score values obtained from our data were in sister pairs LS BMAD analysis. Their values were: 1.32 (P<0.006), 2.61 (P<0.0002) and 2.44 (P<0.0004) in D1S218, D1S2640 and D1S2623 markers, respectively. No significant LOD score was found with LS and FN BMD/BMAD in chromosome 11q region. Only TB BMD showed significant linkage higher than 1.0 for chromosome 11q region in the markers D11S4191 and D11S937. DISCUSSION/CONCLUSIONS: Our results provided suggestive linkage for LS BMAD at D1S2640 marker in adolescent sister pairs and suggest a possible candidate gene (LHX4) related to adolescent LS BMAD in this region. These results reinforce chromosome 1q21-23 as a candidate region to harbor one or more bone formation/maintenance gene. In the other hand, it did not repeat for chromosome 11q12-13 in our population.

Assessment of maximal lactate steady state during treadmill exercise in SHR.

BACKGROUND: Spontaneously hypertensive rats (SHR) are one of the main animal models used for studying the effects of exercise on hypertension. Therefore, the determination of adequate intensity has been essential for secure and optimized exercise prescriptions concerning hypertensive subjects. This study aimed to identify the MLSS in SHR by using a treadmill test to improve the protocols and further prescriptions of exercise intensity. FINDINGS: In order to carry out this determination, SHR (n = 10) animals (~17.5 weeks; 227.4 ± 29.3 g; 172.4 ± 8.1 mmHg systolic blood pressure) were divided into two groups (G1 n = 5; G2 n = 5). Rats underwent a test with three different velocities to determine the MLSS. The MLSS was considered as the highest effort intensity where the blood lactate did not vary more than 1 mmol.L-1 from the 10th to the 25th minute. The MLSS was reached at a velocity of 20 m.min-1 with 3.8 ± 0.5 mmol.L-1 of lactate for G1. Additionally, the results were validated in G2. However, when the test was applied at 25 m.min-1, there was no stabilization of BLC in G1 and G2. CONCLUSIONS: In this study it was possible to identify the MLSS in SHR rats, which is an excellent evaluation tool to control exercise intensity. These data are of considerable importance in studies using physical exercise as a means of research in hypertension and may lead to the intensity of exercise being prescribed more appropriately.