Current research in physiology最新文献

{"title":"Oxygen-enriched air reduces breathing gas consumption over air","authors":"J.D. Schipke ,&nbsp;A. Deussen ,&nbsp;F. Moeller ,&nbsp;U. Hoffmann ,&nbsp;T. Muth ,&nbsp;A. Zenske ,&nbsp;A. Koch","doi":"10.1016/j.crphys.2022.01.007","DOIUrl":"10.1016/j.crphys.2022.01.007","url":null,"abstract":"<div><p>Owing to the unfamiliar environment, recreational and professional diving is confronted with several challenges. Usage of self-contained under-water breathing apparatuses during the dive provides the indispensable breathing gas supply for the diver. Instead of air, oxygen-enriched breathing gases (EANx or nitrox) are used with increasing frequency. Unfortunately, their usage implies negative effects because the elevated oxygen partial pressure (pO₂) increases oxidative stress. As a result, the increased formation of reactive oxygen species exerts negative effects on the central nervous system, lungs, vasculature and eyes. However, these disadvantages can be avoided if appropriate rules are followed, e.g. a pO₂&lt;1.4 bar. EANx breathing gases have, on the other hand, major advantages as they help reducing narcotic nitrogen effects and bubble formation.</p><p>Several land-based studies had proven a reduced ventilation of exercising subjects if EANx was used instead of air. As breathing gas is the most valuable under-water good, we wanted to translate the on-land results into under-water results. Appropriate studies now demonstrate a novel EANx property as under-water ventilation is also reduced with EANx. In this short communication, we present this additional advantage of EANx-breathing. This benefit seems to be of particular importance as it delays unforeseen running-out-of-gas and thus, contributes to further improving diving safety.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 79-82"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9743045/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10362274","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":"Blockade of vasopressin receptors reduces the threshold pressure of micturition reflex in female rats","authors":"Luciana S.S. Neri ,&nbsp;Rodrigo P. de Carvalho ,&nbsp;Sergio A. Daiuto ,&nbsp;Bárbara do Vale ,&nbsp;Eduardo M. Cafarchio ,&nbsp;Patrik Aronsson ,&nbsp;Monica A. Sato","doi":"10.1016/j.crphys.2022.09.004","DOIUrl":"10.1016/j.crphys.2022.09.004","url":null,"abstract":"<div><p>The mechanisms involved in urinary bladder control are not fully understood, but it is well accepted that a complex central network is involved in micturition control. The micturition reflex can be modulated by direct cortical influence through facilitatory and inhibitory mechanisms. In addition, humoral mechanisms are involved in the bladder control. Vasopressin increases bladder contraction and intravesical pressure. This study sought to investigate the effect of intravenous injections of vasopressin receptor antagonists on cystometric parameters in anesthetized female rats. Isoflurane anesthetized adult female Wistar rats underwent femoral artery and vein cannulation for arterial pressure (AP) and heart rate (HR) recordings, and infusion of drugs, respectively. The bladder was also cannulated for intravesical pressure (IP) recordings and infusion of saline (10 mL/h) for cystometric evaluation. After baseline AP, HR and IP recordings, saline (vehicle, 1 mL/kg), V1a (5 μg/kg) or V2 receptor antagonist (5 μg/kg) was injected i.v. and after 25 min the cystometry was carried out. Neither saline nor V1a or V2 receptor blockade evoked any change in AP, HR and IP. Nevertheless, during cystometry, the threshold pressure of the micturition reflex was significantly reduced in rats with V1a (to 19.30 ± 2.39 mmHg) and V2 receptor blockade (to 19.88 ± 2.49 mmHg) compared to the saline group (28.85 ± 2.06 mmHg, p = 0.014). No difference was observed in the other cystometric parameters. Therefore, the data suggest that blockade of V1a and V2 receptors reduces the threshold pressure of the micturition reflex and does not influence other cystometric parameters in anesthetized female Wistar rats.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 399-403"},"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/e6/84/main.PMC9525731.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33486780","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":"Hemodynamic patterns associated with activation of bradykinin-sensitive pericardial afferents","authors":"Douglas Martin,&nbsp;Samuel Drummer,&nbsp;Jessica Freeling,&nbsp;Casey Reihe","doi":"10.1016/j.crphys.2022.01.004","DOIUrl":"10.1016/j.crphys.2022.01.004","url":null,"abstract":"<div><p>The heart is endowed with reflexogenic areas capable of powerful blood pressure responses. Relatively little work has studied the hemodynamic mechanisms underlying these responses and whether these are sexually dimorphic. We hypothesized that activation of bradykinin-sensitive pericardial afferents would produce a sexually dimorphic cardiac output response. Male and female Sprague Dawley rats were anesthetized and instrumented with catheters for recording arterial pressure, with an aortic arch flow probe to record cardiac output and with a catheter in the pericardial sac. Mean arterial pressure (<strong>MAP</strong>), cardiac index (<strong>CI</strong>) and total peripheral resistance index (<strong>TPRI</strong>) responses to pericardial bradykinin injection (0.1, 1 μg/kg) were recorded. Pericardial bradykinin injection caused similar increases in MAP in male and female rats. However, the underlying hemodynamic patterns varied considerably. We identified a cluster of CI responders and TPRI responders in both male and female rats. Within CI responders, females exhibited greater CI increases than males. Conversely, in TPRI responders, males exhibited a greater TPRI increase than females. We conclude that aggregate activation of bradykinin-sensitive pericardial afferents is associated with a relatively uniform pressor response but different hemodynamic patterns with males exhibiting a more robust vascular response and females a more robust cardiac output response.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 73-78"},"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/9e/1c/main.PMC8814590.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39781503","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 comparison of endothelial function of moderate intensity interval exercise with continuous exercise in healthy men","authors":"Burcu Meri̇c ,&nbsp;Serdar Solak ,&nbsp;Nurettin Aydogdu ,&nbsp;Necdet Sut ,&nbsp;Selma Arzu Vardar","doi":"10.1016/j.crphys.2022.07.003","DOIUrl":"10.1016/j.crphys.2022.07.003","url":null,"abstract":"<div><h3>Background/aim</h3><p>Exercise enhances endothelium-dependent vasodilation; however, it is unclear whether intermittent exercise has a different effect on vascular endothelial function compared to continuous exercise. This study aimed to compare vascular endothelial function following intermittent exercise including short rest intervals with continuous exercise, both at the anaerobic threshold level.</p></div><div><h3>Materials and methods</h3><p>Peak oxygen consumption (VO₂ peak) and anaerobic threshold were measured in physically active healthy young men (n = 12) by breath-by-breath analysis. After completion of intermittent exercise consisting of eight 1-min long intervals at the anaerobic threshold intensity with 75-s rest periods, total work was calculated. Equivalent work was done during continuous exercise. Immediately after the two exercise periods, venous blood lactate, endothelial nitric oxide synthase (eNOS), endothelin-1, N-terminal proANP (NTproANP), N-terminal proBNP (NTproBNP), and N-terminal proCNP (NTproCNP) levels were measured. Brachial artery flow-mediated dilatation (FMD) was measured before exercise and 30 min after exercise.</p></div><div><h3>Results</h3><p>Mean VO₂ peak level was 33.42 ± 5.9 ml/min/kg and anaerobic threshold level was 47.33 ± 5.85%. Lactate levels following continuous exercise were higher than levels following intermittent exercise (27.76 ± 7.43 mg/dl, 18.54 ± 4.87 mg/dl respectively; p˂0.05). Endothelin-1, eNOS, NTproANP, NTproBNP, and NTproCNP levels were similar after both modalities of exercise (p &gt; 0.05). No significant difference was found in FMD response when comparing intermittent and continuous exercise (7.05 ± 15.11%, 2.49 ± 16.24% respectively; p &gt; 0.05).</p></div><div><h3>Conclusion</h3><p>Since blood lactate levels are higher following continuous exercise, individuals who find difficulty exercising may prefer an intermittent form of exercise. However, both intermittent and continuous exercise at the anaerobic threshold level seem to not produce a significant acute change in endothelial function in healthy men.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 338-343"},"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/2c/8f/main.PMC9307423.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40625927","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 nitric oxide on the antiarrhythmic effects of ketamine/xylazine in a rat model of acute cardiac ischemia-reperfusion","authors":"Alireza Imani ,&nbsp;Sulail Fatima Rajani ,&nbsp;Kamran Rakhshan ,&nbsp;Mahdieh Faghihi ,&nbsp;Masoumeh Nemati ,&nbsp;Tanaz Parsazadegan","doi":"10.1016/j.crphys.2022.06.008","DOIUrl":"10.1016/j.crphys.2022.06.008","url":null,"abstract":"<div><p>The prevalence of ventricular arrhythmias during general anesthesia is about 70%. In experimental studies on the antiarrhythmic effects of different agents, using anesthetic drugs that do not have any protective properties are preferable. The present study was conducted to investigate molecular mechanisms involved in the antiarrhythmic effects of ketamine/xylazine (K/X).</p><p>Sixty male rats were assigned to eight groups: K/X, L -NAME (25–35 mg/kg) with thiopental (TP), L-NAME (25–35 mg/kg) with ketamine/xylazine, L arginine (100 mg/kg) with thiopental, L-arginine (100 mg/kg) with ketamine/xylazine. After anesthetic induction using TP or K/X, the animals were subjected to 30 min of ischemia. Hemodynamic parameters, ventricular arrhythmias during ischemia, the incidence of ventricular tachycardia (VT), and ventricular fibrillation (VF) were measured. Additionally, in order to assess nitrite/nitrate ratio and LDH after ischemia, serum samples were collected and used.</p><p>Our results showed that in the K/X group, the number of VT and VF, duration of VT (p = 0.006), the severity of arrhythmias (p = 0.0179). There was no VF incidence in this group.</p><p>These protective effects were faded by administration of L-NAME with K/X. The combination of L- Arginine in the TP group decreased the number and duration of VT (p &lt; 0.001, p = 0.0013) with no incidence of VF in comparison with TP. L-arginine with K/X groups increased the number and duration of VT (p &lt; 0.0001, p &lt; 0.001) compared to K/X and VF was seen (100%). However, there was no significant difference between TP and K/X groups in terms of this nitrite/nitrate ratio. These findings suggest that the antiarrhythmic effects of ketamine/xylazine might be partially relative to the nitric oxide synthesis pathway.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 302-311"},"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/6d/e5/main.PMC9287742.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40630810","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":"Zinc and its role in vitamin D function","authors":"Ashton Amos,&nbsp;Mohammed S. Razzaque","doi":"10.1016/j.crphys.2022.04.001","DOIUrl":"10.1016/j.crphys.2022.04.001","url":null,"abstract":"<div><p>Zinc is an essential mineral with an important relationship with vitamin D. Studies have found that reduced blood zinc levels could predict vitamin D deficiency in adolescent girls, while zinc supplementation increased vitamin D levels in postmenopausal women. In vitro studies using human peritoneal macrophages have found that zinc induced the release of calcitriol (1,25-dihydroxycholecalciferol). Zinc also acts as a cofactor for vitamin D functions, as the transcriptional activity of vitamin D-dependent genes relies on zinc to exert pleiotropic functions, including mineral ion regulation. Vitamin D could also induce zinc transporters to regulate zinc homeostasis. Together, zinc and vitamin D in adequate concentrations help maintain a healthy musculoskeletal system and beyond; however, deficiency in either of these nutrients can result in various disorders affecting almost all body systems. This brief article will focus on the role of zinc in vitamin D functions.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 203-207"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2665944122000190/pdfft?md5=4f4a9319a39ff3de95387bb0ec6b88ae&pid=1-s2.0-S2665944122000190-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46604831","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 interactive effects of exercise training and functional feeds on the cardiovascular performance of rainbow trout (Oncorhynchus mykiss) at high temperatures","authors":"Anna Papadopoulou ,&nbsp;Luca Pettinau ,&nbsp;Eila Seppänen ,&nbsp;Asko Sikanen ,&nbsp;Katja Anttila","doi":"10.1016/j.crphys.2022.02.005","DOIUrl":"10.1016/j.crphys.2022.02.005","url":null,"abstract":"<div><p>The cardiovascular performance of salmonids in aquaculture can be impaired by acute climate warming, posing risks for fish survival. Exercise training and functional feeds have been shown to be cardioprotective in mammals but their action on the fish heart and its upper thermal performance has not been studied. To investigate this, rainbow trout were trained at a moderate water velocity of 1 body length per second (bl s⁻¹) for 6 h per day, either alone or in combination with one of two functional feed-supplements, allicin and fucoidan. After 6 weeks of exercise training and feeding, maximum heart rate and the temperature coefficient of heart rate were significantly higher in the trained fish as compared to untrained ones. There was a slight increase in hematocrit in trained control fish reared on a normal diet (TC group) compared to untrained fish fed with the same diet (CC). This implies that exercise training enhanced oxygen delivery to trout tissues via an increase of cardiac blood flow in warm water. However, cardiac thermal tolerance was not affected by exercise training or feeding, except from the temperature of peak heart rate which was higher in the trained group fed with fucoidan supplement (TF) as compared to the untrained group fed with same diet (CF). Allicin supplement caused a significant reduction in the maximum heart rate and the temperature coefficient of heart rate, especially in trained fish, while fucoidan supplement did not cause any effect on heart rate. No differences were observed in growth performance among groups. However, fish fed with fucoidan-supplemented diet had a slight reduction in feed conversion efficiency. We suggest further investigations to understand the antagonistic effect of allicin supplemental feeding and exercise training on cardiovascular performance. More studies are also required to investigate if other exercise training intensities could increase cardiac thermal tolerance.</p></div>","PeriodicalId":72753,"journal":{"name":"Current research in physiology","volume":"5 ","pages":"Pages 142-150"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2665944122000128/pdfft?md5=2afe25e21dbc5ec255bb682192d8efc0&pid=1-s2.0-S2665944122000128-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48936927","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 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}