American journal of physiology. Regulatory, integrative and comparative physiology最新文献

{"title":"Profiling growth performance, insulin-like growth factors, and IGF-binding proteins in rainbow trout lacking IGFBP-2b.","authors":"Beth M Cleveland, Ayaka Izutsu, Yuika Ushizawa, Lisa Radler, Munetaka Shimizu","doi":"10.1152/ajpregu.00209.2024","DOIUrl":"10.1152/ajpregu.00209.2024","url":null,"abstract":"<p><p>Insulin-like growth factor-binding proteins (IGFBPs) regulate insulin-like growth factor (IGF) signaling, but IGFBP-specific functions are not well characterized in fishes. A line of rainbow trout (<i>Oncorhynchus mykiss</i>) lacking a functional IGFBP-2b was produced using gene editing and subsequent breeding to an F2 generation. This loss-of-function model [IGFBP-2b knockout (2bKO)] was subjected to either continuous feeding or feed deprivation (3 wk) followed by refeeding (1 wk). During continuous feeding, the 2bKO line displayed faster specific growth rate for both body weight and fork length, higher feed intake, and reduced feed conversion ratio compared with a wild-type (WT) line. However, loss of IGFBP-2b did not affect the feed deprivation or refeeding response in terms of weight loss or weight gain, respectively. Several components of the IGF/IGFBP system were affected by loss of IGFBP-2b. Total serum IGF-1 in the 2bKO line was reduced to 0.5- to 0.8-fold of the WT line, although the concentration of free serum IGF-1 was not affected. Gene expression differences include reduced abundance of <i>igfbp1a1</i>, <i>igfbp1b2</i>, <i>igfbp5b2</i>, and <i>igfbp6b1</i> transcripts and elevated <i>igf2</i> and <i>igfbp6b2</i> transcripts in liver of the 2bKO line. Collectively, these findings suggest that although IGFBP-2b is a carrier of circulating IGF-1 in salmonids, the presence of IGFBP-2a and compensatory responses of other IGF/IGFBP system components support an anabolic response that improved growth performance in the loss-of-function model.<b>NEW & NOTEWORTHY</b> Knocking out IGFBP-2b in rainbow trout improved food intake, growth performance, and feed conversion ratio and reduced serum IGF-1 by 0.5- to 0.8-fold, without changes in the concentration of free serum IGF-1. Based on these findings, we propose that, in addition to IGFBP-2b, the 32-kDa IGFBP (putative IGFBP-2a) also serves as a major carrier of circulating IGF-1 in salmonids.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R34-R44"},"PeriodicalIF":2.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cardiovascular function and autonomic regulation in urethane-anesthetized and conscious mice.","authors":"Anastasiia Vasileva, Laura D M Flores, Mikhail Vasilyev, Michelle A Buckman, Lara R DeRuisseau, Michael H Tomasson, Melissa L Bates","doi":"10.1152/ajpregu.00097.2024","DOIUrl":"10.1152/ajpregu.00097.2024","url":null,"abstract":"<p><p>Urethane is widely used for its ability to induce prolonged anesthesia. Variability in previously reported cardiovascular parameters in murine models makes it challenging to definitively evaluate the cardiovascular effects of urethane anesthesia. We aimed to address these challenges, thereby advancing our understanding of urethane's effects on cardiovascular function in mice. In this study, we investigated how urethane anesthesia, with and without supplemental oxygen, impacts heart rate, arterial oxygen saturation ([Formula: see text]), blood pressure, and heart rate variability in mice. First, we conducted a literature review and found that data in mice were both limited and lacking in reproduction. Next, we conducted a series of physiological measurements to address gaps in the literature and subjected C57BL/6J mice to three conditions: <i>1</i>) conscious, <i>2</i>) urethane-anesthetized, and <i>3</i>) urethane-anesthetized with supplemental oxygen. Blood pressure, heart rate, [Formula: see text], and heart rate variability (via time, frequency, and M-curve analyses) were assessed. We observed an increase in heart rate with urethane anesthesia (<i>P</i> = 0.012) compared with the conscious state. Urethane caused a decrease in heart rate variability, which was independent of oxygen supplementation. Urethane anesthesia caused a significant reduction in arterial blood pressure (<i>P</i> < 0.001) with oxygen-supplemented mice remained hypotensive. Urethane decreased [Formula: see text] (<i>P</i> = 0.001), which was restored by oxygen supplementation (<i>P</i> < 0.001). We did not observe sex effects of urethane anesthesia on blood pressure, heart rate, heart rate variability, or [Formula: see text]. Taken together, these results underscore the importance of a cautious approach when using urethane in mice, as urethane significantly impacts arterial blood pressure, heart rate, oxygen saturation, and heart rate variability.<b>NEW & NOTEWORTHY</b> This investigation documents cardiovascular outcomes in mice receiving urethane anesthesia, emphasizing sex as a biological variable, and considering oxygen supplementation during anesthesia. This is the first report of M-curve analysis in rodents as a heart rate-independent variability analysis.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R133-R144"},"PeriodicalIF":2.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between regional sympathetic vascular transduction and sympathetic transduction of blood pressure in young adults at rest.","authors":"Devin G McCarthy, Massimo Nardone, Kathryn Pfundt, Philip J Millar","doi":"10.1152/ajpregu.00199.2024","DOIUrl":"10.1152/ajpregu.00199.2024","url":null,"abstract":"<p><p>A burst of muscle sympathetic nerve activity (MSNA) induces vasoconstriction that transiently reduces regional vascular conductance and increases systemic blood pressure (BP) over the subsequent 4-8 cardiac cycles. These responses are termed sympathetic neurovascular transduction and sympathetic transduction of BP, respectively. Sympathetic transduction of BP is commonly calculated and interpreted as a proxy measure for regional sympathetic neurovascular transduction despite the systemic nature of BP regulation. The present analysis tested whether the peak change in signal-averaged sympathetic transduction of BP was correlated to the change in regional sympathetic vascular transduction at rest. Fourteen adults (5 females, 23 ± 3 yr) arrived at the laboratory, ate a standardized meal, and rested for 90-120 min. MSNA (fibular nerve microneurography), heart rate (electrocardiography), beat-to-beat BP (finger photoplethysmography), and superficial femoral artery blood flow (Doppler ultrasound) were obtained continuously for 10 min in the supine position. Femoral vascular conductance (FVC) was calculated as blood flow divided by mean arterial BP. The peak change in diastolic BP following a burst of MSNA was correlated to the corresponding nadir change in femoral vascular conductance (<i>r</i> = -0.58 [-0.07 to -0.85], <i>P</i> = 0.03) and superficial femoral artery blood flow (<i>r</i> = -0.54 [-0.17 to -0.83], <i>P</i> = 0.04). The nadir change in diastolic BP in cardiac cycles not following an MSNA burst was correlated to the peak change in femoral vascular conductance (<i>r</i> = -0.42 [-0.83 to 0.00], <i>P</i> = 0.05), but not superficial femoral artery blood flow (<i>r</i> = 0.41 [-0.77 to 0.15], <i>P</i> = 0.14). In conclusion, more commonly assessed sympathetic transduction of BP provides moderate insight into regional sympathetic neurovascular transduction.<b>NEW & NOTEWORTHY</b> The majority of studies have used signal-averaged sympathetic transduction of blood pressure as a generalized measure of transduction. In this analysis, we show that sympathetic transduction of blood pressure and regional sympathetic vascular transduction were moderately correlated in healthy adults at rest. The moderate strength of this relationship highlights potential differences between regional and systemic assessments of sympathetic transduction and suggests that future work should choose the transduction measure best aligned with the research question.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R528-R533"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142387293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cerebral vasomotor reactivity to carbon dioxide using the rebreathe technique: assessment of within-day and between-day repeatability.","authors":"Damsara Nandadeva, Rachel J Skow, Zachary T Martin, Jordan C Patik, Ziba Taherzadeh, Alison Ortiz, Yungfei Kao, Paul J Fadel, R Matthew Brothers","doi":"10.1152/ajpregu.00030.2024","DOIUrl":"10.1152/ajpregu.00030.2024","url":null,"abstract":"<p><p>The cerebral vasodilator response to increased arterial carbon dioxide (CO₂) concentration, termed cerebral vasomotor reactivity (CVMR), is used to assess cerebral vascular function. We sought to assess the within-day and between-day repeatability of CVMR to rebreathing-induced hypercapnia. Twelve healthy adults performed a <i>within-day short interval</i> protocol (17 ± 2 min between trials), ten performed <i>a within-day long interval</i> protocol (145 ± 16 min between trials), and seventeen performed a <i>between-day</i> protocol (5 ± 2 days between visits). Repeatability of the slope of the percent change in middle cerebral artery mean blood velocity (%MCAv_mean) and cerebral vascular conductance index (%CVCi), to the change in partial pressure of end-tidal CO₂ ([Formula: see text]) between the two trials/days was assessed. <i>Within-day short interval</i>, %MCAv_mean slope demonstrated fair to excellent repeatability (intraclass correlation, ICC = 0.92 [95% confidence interval 0.72-0.98]; <i>P</i> < 0.001) while %CVCi slope showed more variability (ICC = 0.84 [0.47-0.95]; <i>P</i> = 0.002]). <i>Within-day long interval</i>, %MCAv_mean (ICC = 0.95 [0.80-0.99]) and %CVCi (ICC = 0.94 [0.71-0.99]) slopes showed good to excellent and fair to excellent repeatability respectively (<i>P</i> < 0.001 for both). For <i>between-day</i> trials, better repeatability was observed for %CVCi (ICC = 0.85 [0.57-0.95]; <i>P</i> < 0.001) compared with %MCAv_mean (ICC = 0.76 [0.33-0.91]; <i>P</i> = 0.004) slope. These findings indicate repeatable <i>within- and between-day</i> CVMR responses to rebreathe-induced hypercapnia. However, a longer interval may be better for <i>within-day</i> repeat trials, particularly for CVCi measures.<b>NEW & NOTEWORTHY</b> The cerebral vasodilator response to increases in arterial carbon dioxide concentration, termed cerebral vasomotor reactivity, provides an index of cerebral vascular function/health. Reduced responses are present in populations with elevated cerebral vascular and neurocognitive disease risk/overt disease. Cerebral vasomotor reactivity is often assessed during rebreathing-induced hypercapnia. This study determined that the day-to-day and between-day variability in this response is repeatable, thereby providing important methodological information to the scientific community.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R580-R589"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cerebral hemodynamic and systemic physiological changes in trained freedivers completing sled-assisted dives to two different depths.","authors":"Eva-Maria S Bønnelycke, Tommaso A Giacon, Gerardo Bosco, Jana M Kainerstorfer, Matteo Paganini, Alexander Ruesch, Jingyi Wu, J Chris McKnight","doi":"10.1152/ajpregu.00085.2024","DOIUrl":"10.1152/ajpregu.00085.2024","url":null,"abstract":"<p><p>Although existing literature covers significant detail on the physiology of human freediving, the lack of standardized protocols has hindered comparisons due to confounding variables such as exercise and depth. By accounting for these variables, direct depth-dependent impacts on cardiovascular and blood oxygen regulation can be investigated. In this study, depth-dependent effects on <i>1</i>) cerebral hemodynamic and oxygenation changes, <i>2</i>) arterial oxygen saturation ([Formula: see text]), and <i>3</i>) heart rate during breath-hold diving without confounding effects of exercise were investigated. Six freedivers (51.0 ± 12.6 yr; means ± SD), instrumented with continuous-wave near-infrared spectroscopy for monitoring cerebral hemodynamic and oxygenation measurements, heart rate, and [Formula: see text], performed sled-assisted breath-hold dives to 15 m and 42 m. Arterial blood gas tensions were validated through cross-sectional periodic blood sampling. Cerebral hemodynamic changes were characteristic of breath-hold diving, with changes during ascent from both depths likely driven by decreasing [Formula: see text] due to lung expansion. Although [Formula: see text] was significantly lower following 42-m dives [<i>t</i>(5) = -4.183, <i>P</i> < 0.05], mean cerebral arterial-venous blood oxygen saturation remained at 74% following dives to both depths. Cerebral oxygenation during ascent from 42 m may have been maintained through increased arterial delivery. Heart rate was variable with no significant difference in minimum heart rate between both depths [<i>t</i>(5) = -1.017, <i>P</i> > 0.05]. This study presents a standardized methodology, which could provide a basis for future research on human freediving physiology and uncover ways in which freedivers can reduce potential risks of the sport.<b>NEW & NOTEWORTHY</b> We present a standardized methodology in which trained breath-hold divers instrumented with wearable near-infrared spectroscopy (NIRS) technology and a cannula for arterial blood sampling completed sled-assisted dives to two different dive depths to account for the confounding factors of exercise and depth during breath-hold diving. In our investigation, we highlight the utility of wearable NIRS systems for continuous hemodynamic and oxygenation monitoring to investigate the impacts of hydrostatic pressure on cardiovascular and blood oxygen regulation.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R553-R567"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11687848/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-exercise hot-water immersion is not effective for ribosome biogenesis in rat skeletal muscle.","authors":"Takaya Kotani, Yuki Tamura, Karina Kouzaki, Kazushige Sasaki, Koichi Nakazato","doi":"10.1152/ajpregu.00068.2024","DOIUrl":"10.1152/ajpregu.00068.2024","url":null,"abstract":"<p><p>Ribosome biogenesis is an important regulator of skeletal muscle hypertrophy induced by repeated bouts of resistance exercise (RE). Hot-water immersion (HWI), a widely used post-exercise recovery strategy, activates the mechanistic target of rapamycin (mTOR) signaling, a key regulator of ribosome biogenesis in skeletal muscle. However, the effect of HWI on skeletal muscle ribosome biogenesis is not well understood. Here, we aimed to investigate the effects of HWI and post-exercise HWI on ribosome biogenesis using a rat RE model. Male Sprague-Dawley rats were randomly assigned to HWI and non-HWI groups. In both groups, the right leg was isometrically exercised using transcutaneous electrical stimulation, while the left leg was used as an internal non-RE control. Following RE, both limbs were immersed in hot water (41.2 ± 0.03°C) for 20 min under isoflurane anesthesia in the HWI group and the gastrocnemius muscles were sampled at 3- and 24-h post-exercise. HWI significantly increased mTOR signaling and <i>c-Myc</i> mRNA expression, whereas post-exercise HWI significantly increased transcription initiation factor-IA mRNA expression. However, neither HWI nor post-exercise HWI enhanced 45S pre-rRNA expression, ribosomal RNA, or ribosomal protein content. In addition, HWI tended to decrease 28S rRNA and 18S rRNA content, widely used markers of ribosome content. These results suggest that HWI as a post-exercise recovery is not effective in activating ribosome biogenesis.<b>NEW & NOTEWORTHY</b> Ribosome biogenesis is crucial in resistance exercise (RE)-induced skeletal muscle hypertrophy. This study examined the effects of hot-water immersion (HWI) on ribosome biogenesis after RE. HWI and post-exercise HWI increased c-<i>Myc</i> and transcription initiation factor-IA mRNA but did not alter ribosomal RNA transcription or ribosomal protein content. HWI tended to decrease 28S and 18S ribosomal RNA. These findings suggest that HWI, as a recovery strategy, does not effectively promote ribosome biogenesis or muscle protein synthesis.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R601-R615"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Steering toward new horizons: a vision for the future of the <i>American Journal of Physiology-Regulatory, Integrative and Comparative Physiology</i>.","authors":"Kamal Rahmouni","doi":"10.1152/ajpregu.00252.2024","DOIUrl":"10.1152/ajpregu.00252.2024","url":null,"abstract":"","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R525-R527"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11687851/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is muscle sympathetic nerve activity associated with cerebral blood velocity? A partial coherence analysis.","authors":"Edgar Toschi-Dias, Ricardo C Nogueira, Edna O Silva, Graziela Amaro-Vicente, Carlos E Negrão, Maria Urbana P B Rondon, Ronney B Panerai","doi":"10.1152/ajpregu.00112.2024","DOIUrl":"10.1152/ajpregu.00112.2024","url":null,"abstract":"<p><p>Despite some evidence, the role of sympathetic nerve activity in the regulation of cerebral blood flow remains controversial. In humans, muscle sympathetic nervous activity (MSNA) is the only direct measure of sympathetic nerve activity that can be recorded with sufficient temporal resolution to allow association with dynamic regulation of cerebral blood velocity (CBv). This study tested the hypothesis that MSNA is associated with the regulation of CBv at rest and during different physiological maneuvers. Nine healthy subjects underwent two sympathoexcitatory maneuvers: <i>1</i>) isometric handgrip exercise (HGR), and <i>2</i>) cold pressor test (CPT). Mean arterial pressure (MAP; oscillometric method), CBv (transcranial Doppler ultrasound), and MSNA (microneurography) were measured continuously during experimental protocols. Ordinary and partial coherences of the MAP, CBv, and MSNA time series were estimated by transfer function analysis in the low-frequency range (0.07-0.20 Hz), using MAP and MSNA as inputs and CBv as the output variable. When the influence of MSNA was taken into account, the partial coherences between MAP and CBv were considerably reduced at baseline (<i>P</i> < 0.01), HGR (<i>P</i> = 0.02), and CPT (<i>P</i> < 0.01). Similarly, when the influence of MAP was taken into account, the coherence between MSNA and CBv was considerably reduced at baseline (<i>P</i> < 0.01), HGR (<i>P</i> = 0.02), and CPT (<i>P</i> = 0.01), leading to the conclusion, that MSNA was associated to dynamic regulation of CBv. Partial coherence analysis is a promising method for assessing the influence of the sympathetic nervous system on cerebral hemodynamics.<b>NEW & NOTEWORTHY</b> Partial coherence analysis has been instrumental in demonstrating, for the first time, that cerebral blood velocity (CBv) is continuously influenced, not only by fluctuations in mean arterial pressure but also muscle sympathetic nervous activity (MSNA), leading to similar dynamic responses at rest and during different sympathoexcitatory maneuvers in healthy subjects. Modeling the temporal relationship between MSNA and CBv opens new opportunities for advancing knowledge regarding the role of the sympathetic nervous system in the regulation of cerebral circulation in health and disease.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R590-R600"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute salivary antimicrobial peptide secretion response to different exercise intensities and durations.","authors":"Reita Ito, Takamasa Uchino, Masataka Uchida, Shumpei Fujie, Keiko Iemitsu, Chihiro Kojima, Mariko Nakamura, Kazuhiro Shimizu, Yuko Tanimura, Yasushi Shinohara, Takeshi Hashimoto, Tadao Isaka, Motoyuki Iemitsu","doi":"10.1152/ajpregu.00132.2024","DOIUrl":"10.1152/ajpregu.00132.2024","url":null,"abstract":"<p><p>Antimicrobial peptides, key players of innate mucosal immunity in the oral cavity, exert antibacterial and bacteriolytic effects. This study aimed to clarify the effects of acute exercise at different intensities and durations on salivary antimicrobial peptide levels. In a randomized crossover trial, 14 young healthy untrained men performed intensity trials [cycling at 35%, 55%, and 75% of maximal oxygen uptake (V̇o_2max) for 30 min] and duration trials (cycling at 55% V̇o_2max for 30, 60, and 90 min). Saliva samples were collected at baseline and 0 and 60 min after exercise. In intensity trials, the change in salivary lactoferrin levels from baseline to 0 min after 30 min exercise was greater at 75% V̇o_2max exercise intensity compared with that at 35% V̇o_2max. Furthermore, the change in salivary human β-defensin-2 (HBD-2) levels was greater at 75% V̇o_2max compared with that at 35% and 55% V̇o_2max. Salivary lysozyme levels increased after exercise, independent of exercise intensity. However, salivary LL-37 levels did not change after exercise at any intensity. In addition, in duration trials, the change in salivary levels of LL-37 and HBD-2 from baseline to 0 min after exercise at 55% V̇o_2max was greater after 60 and 90 min of exercise compared with that after 30 min of exercise. However, salivary lactoferrin and lysozyme levels increased after exercise, independent of exercise duration. Our findings suggest that secretory responses to acute exercise with exercise intensity and duration differ among salivary antimicrobial peptides.<b>NEW & NOTEWORTHY</b> We investigated the effects of acute exercise at different intensities and durations on the immune response to salivary antimicrobial peptides in young healthy men. Levels of four salivary antimicrobial peptides increased after exercise dependently or independently of exercise intensity and duration, whereas some salivary antimicrobial peptides did not change after exercise. These findings suggest that the secretory responses to acute exercise with different intensities and durations differ among salivary antimicrobial peptides.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R616-R622"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of cutaneous vasodilation by reactive oxygen species during local and whole body heating in young and older adults.","authors":"Gregory W McGarr, Caroline Li-Maloney, Kelli E King, Kristina-Marie T Janetos, Naoto Fujii, Tatsuro Amano, Glen P Kenny","doi":"10.1152/ajpregu.00127.2024","DOIUrl":"10.1152/ajpregu.00127.2024","url":null,"abstract":"<p><p>We evaluated reactive oxygen species (ROS) modulation of cutaneous vasodilation during local and whole body passive heating in young and older adults. Cutaneous vascular conductance normalized to maximum vasodilation (%CVC_max) was assessed in young and older adults (10/group) using laser-Doppler flowmetry at four dorsal forearm sites treated with <i>1</i>) Ringer solution (control), <i>2</i>) 100 µM apocynin (NADPH oxidase inhibitor), <i>3</i>) 10 µM allopurinol (xanthine oxidase inhibitor), or <i>4</i>) 10 µM tempol (superoxide dismutase mimetic), via intradermal microdialysis during local (<i>protocol 1</i>) and whole body heating (<i>protocol 2</i>). In <i>protocol 1</i>, forearm skin sites were set at 33°C during baseline and then progressively increased to 39°C and 42°C (30 min each). In <i>protocol 2</i>, participants were immersed in warm water (35°C, midsternum) with the experimental forearm above water level, and local skin sites were maintained at 34°C. Bath temperature was increased (∼40°C) to clamp core temperature at 38.5°C for 60 min. In <i>protocol 1</i>, there were significant treatment site by age interactions for the 39°C (<i>P</i> = 0.015) and 42°C (<i>P</i> = 0.004) plateaus; however no significant effects were observed after post hoc adjustment. In <i>protocol</i> 2, there was a significant treatment site by age interaction (<i>P</i> < 0.001), where %CVC_max in older adults was 11.0% [7.4, 14.6] higher for apocynin (<i>P</i> < 0.001), 8.9% [5.3, 12.5] higher for allopurinol (<i>P</i> < 0.001), and 4.8% [1.3, 8.4] higher for tempol (<i>P</i> = 0.016) sites relative to the control site. ROS derived from NADPH oxidase and xanthine oxidase attenuate cutaneous vasodilation in older adults during passive whole body heating, but not during local skin heating, with negligible effects on their young counterparts for either heating modality.<b>NEW & NOTEWORTHY</b> We found that local infusion of apocynin or allopurinol improved cutaneous vasodilator responses to passive whole body heating (but not local skin heating) in healthy older adults. These findings indicate that impaired microvascular responses to whole body heating with primary aging are linked to augmented production of reactive oxygen species (ROS) from NADPH oxidase and xanthine oxidase. This study sheds new light on the specific ROS pathways that modulate age-related changes in cutaneous microvascular responses to heating.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R543-R552"},"PeriodicalIF":2.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}