Current research in physiology最新文献

{"title":"The role of exercise training on cardiovascular peptides in patients with heart failure: A systematic review and meta-analysis","authors":"Abbas Malandish ,&nbsp;Niloufar Ghadamyari ,&nbsp;Asma Karimi ,&nbsp;Mahdi Naderi","doi":"10.1016/j.crphys.2022.06.004","DOIUrl":"10.1016/j.crphys.2022.06.004","url":null,"abstract":"<div><h3>Background</h3><p>The purpose of this systematic review &amp; meta-analysis was to determine the roles of aerobic, resistance or concurrent exercises vs. control (CON) group on B-type natriuretic peptide (BNP) and N-terminal-pro hormone BNP (NT-proBNP) in patients with heart failure.</p></div><div><h3>Methods</h3><p>The electronic databases of PubMed, Scopus, Web of Science, and Google Scholar were searched up to May 2022 for aerobic vs. CON, resistance vs. CON, and concurrent vs. CON studies on circulating (serum or plasma) levels of BNP and NT-proBNP in patients with heart failure. Non-randomized or randomized controlled trial studies were included. Standardized mean difference (SMD) and 95% confidence intervals (95% CIs) were calculated. This systematic review &amp; meta-analysis was registered in PROSPERO at the University of York with the registration number [CRD42021271632].</p></div><div><h3>Results</h3><p>A total of 28 articles (37 intervention arms), 26 aerobic intervention arms, 3 resistance intervention arms, and 8 concurrent intervention arms were included. A total of 2563 participants (exercise groups = 1350 and CON groups = 1213) were included. Exercise training significantly decreased NT-proBNP marker [-0.229 (SMD and 95% CI: 0.386 to −0.071), p = 0.005], irrespective of overweight/obesity status. Analysis of subgroup by type of exercise training revealed that there was a significant reduction in the NT-proBNP marker for aerobic exercise group compared to the CON group [-0.336 (SMD and 95% CI: 0.555 to −0.105), p = 0.004], whereas concurrent exercise did not show significant changes in the NT-proBNP marker [-0.134 (SMD and 95% CI: 0.350 to 0.083), p = 0.227]. In addition, exercise training did not significantly change the BNP marker [-0.122 (SMD and 95% CI: 0.322 to 0.079), p = 0.235].</p></div><div><h3>Conclusions</h3><p>The results suggested that exercise training, especially aerobic exercise can be improved the NT-proBNP concentrations in patients with HF (irrespective of overweight/obesity status), which may be a sign of positive physiological adaptations to aerobic exercise.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 270-286"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/bf/47/main.PMC9253836.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40480546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The air-breathing Alaska blackfish (Dallia pectoralis) remodels ventricular Ca2+ cycling with chronic hypoxic submergence to maintain ventricular contractility","authors":"Holly A. Shiels ,&nbsp;Ed White ,&nbsp;Christine S. Couturier ,&nbsp;Diarmid Hall ,&nbsp;Shannon Royal ,&nbsp;Gina L.J. Galli ,&nbsp;Jonathan A.W. Stecyk","doi":"10.1016/j.crphys.2022.01.001","DOIUrl":"https://doi.org/10.1016/j.crphys.2022.01.001","url":null,"abstract":"<div><p>The Alaska blackfish (<em>Dallia pectoralis</em>) is a facultative air-breather endemic to northern latitudes where it remains active in winter under ice cover in cold hypoxic waters. To understand the changes in cellular Ca²⁺ cycling that allow the heart to function in cold hypoxic water, we acclimated Alaska blackfish to cold (5 °C) normoxia or cold hypoxia (2.1–4.2 kPa; no air access) for 5–8 weeks. We then assessed the impact of the acclimation conditions on intracellular Ca²⁺ transients (Δ[Ca²⁺]_i) of isolated ventricular myocytes and contractile performance of isometrically-contracting ventricular strips. Measurements were obtained at various contractile frequencies (0.2–0.6 Hz) in normoxia, during acute exposure to hypoxia, and reoxygenation at 5 °C. The results show that hypoxia-acclimated Alaska blackfish compensate against the depressive effects of hypoxia on excitation-contraction coupling by remodelling cellular Δ[Ca²⁺]_i to maintain ventricular contractility. When measured at 0.2 Hz in normoxia, hypoxia-acclimated ventricular myocytes had a 3.8-fold larger Δ[Ca²⁺]_i peak amplitude with a 4.1-fold faster rate of rise, compared to normoxia-acclimated ventricular myocytes. At the tissue level, maximal developed force was 2.1-fold greater in preparations from hypoxia-acclimated animals. However, maximal attainable contraction frequencies in hypoxia were lower in hypoxia-acclimated myocytes and strips than preparations from normoxic animals. Moreover, the inability of hypoxia-acclimated ventricular myocytes and strips to contract at high frequency persisted upon reoxygenation. Overall, the findings indicate that hypoxia alters aspects of Alaska blackfish cardiac myocyte Ca²⁺ cycling, and that there may be consequences for heart rate elevation during hypoxia, which may impact cardiac output <em>in vivo</em>.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 25-35"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2665944122000013/pdfft?md5=2cbb6bba379a29280476b142afa6c62a&pid=1-s2.0-S2665944122000013-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91635989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of beta blockade on the cardio-respiratory system and symptoms during exercise","authors":"Eldar Priel ,&nbsp;Mustafaa Wahab ,&nbsp;Tapas Mondal ,&nbsp;Andy Freitag ,&nbsp;Paul M. O'Byrne ,&nbsp;Kieran J. Killian ,&nbsp;Imran Satia","doi":"10.1016/j.crphys.2021.10.002","DOIUrl":"10.1016/j.crphys.2021.10.002","url":null,"abstract":"<div><h3>Background</h3><p>Beta blockers prolong life in patients with cardiovascular diseases. Negative chronotropic and inotropic effects carry the potential to adversely effect peripheral skeletal and airway smooth muscle contributing to further fatigue, dyspnea and exercise intolerance.</p></div><div><h3>Research questions</h3><p>Do beta-blockers reduce maximal power output (MPO), VO2 max, cardiorespiratory responses, increase the perceived effort required to cycle and breath during cardiopulmonary exercise tests (CPET) and limit the capacity to exercise?</p></div><div><h3>Methods</h3><p>Retrospective observational study of subjects performing CPET to capacity from 1988 to 2012. Subjects with and without beta-blockers were compared: baseline physiological characteristics, MPO, VO₂ max, heart rate max, ventilation responses and perceived exertion required to cycle and breathe (modified Borg scale). Forward stepwise linear additive regression was performed with MPO as the dependent factor with height, age, gender, muscle strength, FEV1 and DLCO as independent contributors.</p></div><div><h3>Results</h3><p>42,771 subjects were included 7,787 were receiving beta-blocker [mean age 61 yrs, BMI 28.40 kg/m², 9% airflow obstruction (FEV1/FVC&lt;0.7)] and 34,984 were not [mean age 51yrs, BMI 27.40 kg/m², 11% airflow obstruction]. Heart rate was lower by 18.2% (95% C.I. 18.15–18.38) (p&lt;0.0001) while Oxygen pulse (VO₂/HR) was higher by 19.5% (95% C.I. 19.3–19.7) in those receiving beta blockers. Maximum power output (MPO) was 3.3% lower in those taking beta-blockers. The perceived effort required to cycle and breathe (mBorg) was 8% lower in those taking beta-blockers.</p></div><div><h3>Interpretation</h3><p>Increases in oxygen pulse minimize the reduction in exercise intolerance and symptom handicap associated with beta-blockers.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 235-242"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/f8/03/main.PMC8710988.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39649773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of crista morphology on mitochondrial ATP output: A computational study","authors":"Nasrin Afzal ,&nbsp;W. Jonathan Lederer ,&nbsp;M. Saleet Jafri ,&nbsp;Carmen A. Mannella","doi":"10.1016/j.crphys.2021.03.005","DOIUrl":"10.1016/j.crphys.2021.03.005","url":null,"abstract":"<div><p>Folding of the mitochondrial inner membrane (IM) into cristae greatly increases the ATP-generating surface area, <em>S</em>_{<strong>IM</strong>}, per unit volume but also creates diffusional bottlenecks that could limit reaction rates inside mitochondria. This study explores possible effects of inner membrane folding on mitochondrial ATP output, using a mathematical model for energy metabolism developed by the Jafri group and two- and three-dimensional spatial models for mitochondria, implemented on the Virtual Cell platform. Simulations demonstrate that cristae are micro-compartments functionally distinct from the cytosol. At physiological steady states, standing gradients of ADP form inside cristae that depend on the size and shape of the compartments, and reduce local flux (rate per unit area) of the adenine nucleotide translocase. This causes matrix ADP levels to drop, which in turn reduces the flux of ATP synthase. The adverse effects of membrane folding on reaction fluxes increase with crista length and are greater for lamellar than tubular crista. However, total ATP output per mitochondrion is the product of flux of ATP synthase and <em>S</em>_{<strong>IM</strong>} which can be two-fold greater for mitochondria with lamellar than tubular cristae, resulting in greater ATP output for the former. The simulations also demonstrate the crucial role played by intracristal kinases (adenylate kinase, creatine kinase) in maintaining the energy advantage of IM folding.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 163-176"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crphys.2021.03.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39314276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aqueous extract of Tetrapleura tetraptera fruit peels influence copulatory behavior and maintain testicular integrity in sexually mature male Sprague-Dawley rats: Pro-fertility evaluation and histomorphometry evidence","authors":"Sunday Aderemi Adelakun ,&nbsp;Babatunde Ogunlade ,&nbsp;Toluwase Solomon Olawuyi ,&nbsp;Abdulfatai Olakunle Ojewale","doi":"10.1016/j.crphys.2021.01.001","DOIUrl":"10.1016/j.crphys.2021.01.001","url":null,"abstract":"<div><p>Tetrapleura tetraptera (TT) has been used as a spice, dietary supplement and medicine for various ailments. This study evaluate influence of Tetrapleura tetraptera extract on testis and copulatory behavior in sexually mature male rats.</p><p>Thirty-two male and sixty-four virgin female rats weighing 150–200 g were used for this study. Male rats randomly divided into four groups of eight (n = 8) rats each. Group A: Control given 2 ml distilled water, group B, C and D received 50, 300 and 700 mg/kg bwt TT for 56 days through oral gavage. The female rats were used for fertility test. Testicular histology, histomorphology, copulatory behavior, sperm parameters, testosterone (TET), luteinizing hormone (LH), follicle stimulating hormone (FSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and fertility test were investigated.</p><p>Tetrapleura tetraptera significantly increase sperm count, motility, normal morphology, daily sperm production, efficiency of sperm production, sperm (average path velocity, straight line velocity and curvilinear velocity), TET, LH, FHS, SOD, GPx, CAT, number of pregnant females, number of fetuses, seminiferous diameter, epithelium thickness and decrease abnormal morphology, seminiferous height, tubule lumen and MDA across the group as compared with control group. Improved testicular histological integrity, sexual behaviour and libido by increased frequencies of mount, intromission, ejaculation and ejaculatory latency. Latencies of mount, intromission and post-ejaculation were significantly reduced. Also, observed increase spermatocytes and spermatids showed no significant difference in spermatogonia cell counts. Tetrapleura tetraptera therefore, enhance steroidogenesis, spermatogenesis, and improved testicular histological integrity and boost sexual competence in male rats.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 7-16"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crphys.2021.01.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39599281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of glycinergic inhibition in respiratory pattern formation and cardio-respiratory coupling in rats","authors":"Werner Issao Furuya,&nbsp;Rishi R. Dhingra,&nbsp;Pedro Trevizan-Baú,&nbsp;Robin M. McAllen,&nbsp;Mathias Dutschmann","doi":"10.1016/j.crphys.2021.03.001","DOIUrl":"10.1016/j.crphys.2021.03.001","url":null,"abstract":"<div><p>Cardio-respiratory coupling is reflected as respiratory sinus arrhythmia (RSA) and inspiratory-related bursting of sympathetic nerve activity. Inspiratory-related inhibitory and/or postinspiratory-related excitatory drive of cardiac vagal motoneurons (CVMs) can generate RSA. Since respiratory oscillations may depend on synaptic inhibition, we investigated the effects of blocking glycinergic neurotransmission (systemic and local application of the glycine receptor (GlyR) antagonist, strychnine) on the expression of the respiratory motor pattern, RSA and sympatho-respiratory coupling. We recorded heart-rate, phrenic, recurrent laryngeal and thoracic sympathetic nerve activities (PNA, RLNA, t-SNA) in a working-heart-brainstem preparation of rats, and show that systemic strychnine (50–200 ​nM) abolished RSA and triggered a shift of postinspiratory RLNA into inspiration, while t-SNA remained unchanged. Bilateral strychnine microinjection into the ventrolateral medullary area containing CVMs and laryngeal motoneurons (LMNs) of the nucleus ambiguus (NA/CVLM), the nucleus tractus solitarii, pre-Bötzinger Complex, Bötzinger Complex or Kölliker-Fuse nuclei revealed that only NA/CVLM strychnine microinjections mimicked the effects of systemic application. In all other target nuclei, except the Bötzinger Complex, GlyR-blockade attenuated the inspiratory-tachycardia of the RSA to a similar degree while evoking only a modest change in respiratory motor patterning, without changing the timing of postinspiratory-RLNA, or t-SNA. Thus, glycinergic inhibition at the motoneuronal level is involved in the generation of RSA and the separation of inspiratory and postinspiratory bursting of LMNs. Within the distributed ponto-medullary respiratory pre-motor network, local glycinergic inhibition contribute to the modulation of RSA tachycardia, respiratory frequency and phase duration but, surprisingly it had no major role in the mediation of respiratory-sympathetic coupling.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 80-93"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crphys.2021.03.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39599253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Watermelon rind ethanol extract exhibits hepato-renal protection against lead induced-impaired antioxidant defenses in male Wistar rats","authors":"Olugbenga S. Michael ,&nbsp;Olubayode Bamidele ,&nbsp;Pamela Ogheneovo ,&nbsp;Temitope A. Ariyo ,&nbsp;Lawrence D. Adedayo ,&nbsp;Olufemi I. Oluranti ,&nbsp;Elizabeth O. Soladoye ,&nbsp;Charles O. Adetunji ,&nbsp;Funmileyi O. Awobajo","doi":"10.1016/j.crphys.2021.11.002","DOIUrl":"10.1016/j.crphys.2021.11.002","url":null,"abstract":"<div><p>Lead acetate associated tissue injury has been linked to altered antioxidant defenses, hyperuricemia and inflammation. We hypothesized that watermelon rind extract, would ameliorate lead acetate-induced hepato-renal injury.</p><p>Thirty Male Wistar rats received distilled water, lead acetate (Pb; 5 mg/kg) with or without watermelon rind extract (WM; 400 mg/kg; WM + Pb; 15 days of WM pretreatment); Pb + WM (15 days of WM post treatment) and simultaneous treatment (WM-Pb) for 30 days.</p><p>Lead toxicity led to elevated serum malondialdehyde, creatinine, urea, uric acid, lactate dehydrogenase, liver injury enzymes, as well as decreased body weight. Decreased serum levels of reduced glutathione, nitric oxide, total protein and glutathione peroxidase activity was also observed. However, these alterations were ameliorated by watermelon rind extract in lead acetate-treated rats.</p><p>Watermelon rind ethanol extract protects against lead acetate-induced hepato-renal injury through improved antioxidant defenses at least in part, via uric acid/nitric oxide-dependent pathway signifying the health benefits of this agricultural waste and a potential for waste recycling while limiting environmental pollution.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 252-259"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/1e/49/main.PMC8607130.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39674301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protective role of Allium cepa Linn (onion) juice on maternal dexamethasone induced alterations in reproductive functions of female offspring of Wistar rats","authors":"S.O. Jeje ,&nbsp;E.E. Akpan ,&nbsp;O.T. Kunle-Alabi ,&nbsp;O.O. Akindele ,&nbsp;Y. Raji","doi":"10.1016/j.crphys.2021.06.001","DOIUrl":"10.1016/j.crphys.2021.06.001","url":null,"abstract":"<div><p>Maternal treatment with dexamethasone induces oxidative stress in the reproductive structures of offspring. Consumption of <em>Allium cepa Linn</em> improves antioxidant status. This study was designed to evaluate the protective role of <em>Allium cepa Linn</em> juice on maternal dexamethasone induced alterations in reproductive functions of the female offspring of Wistar rats.</p><p>Twenty lactating dams (180–200 ​g) were randomly assigned into four groups (n ​= ​5) on the day of parturition and treated as follows during lactation for 21 days: Control (5 ​ml/kg BW distilled water); Dexamethasone (60 ​μg/kg BW); <em>Allium cepa</em> (5 ​ml/kg BW); Dexamethasone ​+ ​<em>Allium cepa</em> (60 ​μg/kg BW ​+ ​5 ​ml/kg BW). The female offspring were separated at birth. Days of vaginal opening and first oestrus cycle, length and frequency of estrous cycle as well as serum hormonal profiles were assessed as measure of reproductive functions. Ovarian superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) level were measured as indices of oxidative stress.</p><p>Oestrous cycle length, frequencies of diestrus as well as the Ovarian MDA were significantly increased (p ​&lt; ​0.05) in dexamethasone (DEX) group relative to control group. Serum 17β-oestradiol and corticosterone level in addition to SOD and catalase activities were significantly reduced (p ​&lt; ​0.05) in DEX group relative to control. Co-administration of Dex with <em>Allium cepa Linn</em> juice reduced the oestrous length, frequency of diestrous as well as ovarian MDA. There was also a significant increase in serum 17β-oestradiol, ovarian SOD and catalase activity.</p><p>The results suggest that <em>Allium cepa</em> could protect against alterations in reproductive functions of offspring induced by maternal treatment with dexamethasone during lactation in Wistar rats. The flavonoid constituent of onion may also help in reducing oxidative stress in the offspring.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 145-154"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crphys.2021.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39852611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of physiological and clinical markers for chronic sprint-interval training exercise performed either in the fasted or fed states among healthy adults","authors":"Victor Tan ,&nbsp;Ivy Lim ,&nbsp;Pei Ting Tan ,&nbsp;Frankie Tan ,&nbsp;Abdul Rashid Aziz","doi":"10.1016/j.crphys.2021.09.003","DOIUrl":"10.1016/j.crphys.2021.09.003","url":null,"abstract":"<div><h3>Objective</h3><p>Sprint-interval training (SIT) and intermittent fasting are effective independent methods in achieving clinical health outcomes. However, the impact of both modalities when performed concurrently is unclear. The aim of this study was to compare the effects of 6 weeks of SIT performed in the fasted versus fed state on physiological and clinical health markers in healthy adults. <em>Methods.</em> Thirty recreationally-active participants were equally randomised into either the fasted (FAS; 4 males, 11 females) or the fed (FED; 6 males, 9 females) group. For all exercise sessions, FAS participants had to fast ≥10 h prior to exercising while FED participants had to consume food within 3 h to exercise. All participants underwent three sessions of SIT per week for 6 weeks. Each session consists of repeated bouts of 30-s Wingate Anaerobic cycle exercise. Pre- and post-training peak oxygen uptake (VO_2peak), isokinetic leg strength, insulin sensitivity, blood pressure and serum lipid levels were assessed. <em>Results.</em> There were no differences in baseline physiological and clinical measures between both groups (all <em>p</em> &gt; 0.05). VO_2peak improved by 6.0 ± 8.8% in the FAS group and 5.3 ± 10.6% in the FED group (both <em>p</em> &lt; 0.05), however the difference in improvement between groups was not statistically significant (<em>p</em> &gt; 0.05). A similar pattern of results was seen for knee flexion maximum voluntary contraction at 300°·s⁻¹. SIT training in either fasted or fed state had no impact on insulin sensitivity (both <em>p</em> &gt; 0.05). There was significant reduction in diastolic blood pressure (8.2 ± 4.2%) and mean arterial pressure (7.0 ± 3.2%) in the FAS group (both <em>p</em> &lt; 0.05) but not FED group (both <em>p</em> &gt; 0.05). <em>Conclusion.</em> VO_2peak and leg strength improved with SIT regardless of whether participants trained in the fasted or fed state. Chronic SIT in the fasted state may potentially reduce blood pressure to a greater extent than the same chronic SIT in the fed state.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 192-201"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/89/89/main.PMC8562244.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39852615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of lactate administration on mouse skeletal muscle under calorie restriction","authors":"Takanaga Shirai ,&nbsp;Kazuki Uemichi ,&nbsp;Yuki Hidaka ,&nbsp;Yu Kitaoka ,&nbsp;Tohru Takemasa","doi":"10.1016/j.crphys.2021.09.001","DOIUrl":"10.1016/j.crphys.2021.09.001","url":null,"abstract":"<div><p>Calorie restriction (CR) involves a reductions of calorie intake without altering the nutritional balance, and has many beneficial effects, such as improving oxidative metabolism and extending lifespan. However, CR decreases in skeletal muscle mass and fat mass in correlation with the reduction in food intake. Lactate is known to have potential as a signaling molecule rather than a metabolite during exercise. In this study, we examined the effects of the combination of caloric restriction and lactate administration on skeletal muscle adaptation in order to elucidate a novel role of lactate. We first demonstrated that daily lactate administration (equivalent to 1 g/kg of body weight) for 2 weeks suppressed CR-induced muscle atrophy by activating mammalian/mechanistic target of rapamycin (mTOR) signaling, a muscle protein synthesis pathway, and inhibited autophagy-induced muscle degradation. Next, we found that lactate administration under calorie restriction enhanced mitochondrial enzyme activity (citrate synthase and succinate dehydrogenase) and the expression of oxidative phosphorylation (OXPHOS) protein expression. Our results suggest that lactate administration under caloric restriction not only suppresses muscle atrophy but also improves mitochondrial function.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"4 ","pages":"Pages 202-208"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8562144/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39852616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}