Journal of applied physiology最新文献

{"title":"The effect of heat acclimation on critical environmental limits and rate of rectal temperature change.","authors":"Timo van den Bogaard, Lisa Klous, Rachel M Cottle, Jan Van Erp, Hein A M Daanen","doi":"10.1152/japplphysiol.01004.2024","DOIUrl":"10.1152/japplphysiol.01004.2024","url":null,"abstract":"<p><p>Quantifying the effect of heat acclimation (HA) on critical wet-bulb globe temperature (WBGT_crit) and rate of rectal temperature change (vT_re) is relevant for developing guidelines with regards to occupational safety while working in warm environments. This study quantified the effect of HA and the period following cessation of the HA protocol on WBGT_crit and vT_re. Twenty-eight non-acclimatized participants were divided into a HA (<i>n</i> = 15) and control (CON; <i>n</i> = 13) group. The HA group underwent a warm-humid (35°C, 65% relative humidity) controlled hyperthermia HA protocol (5-9 days of achieving T_re ∼38.5°C for 60 min) and four progressive heat stress tests (HSTs) to identify WBGT_crit and examine vT_re: pre-, after 5 and 9 days of HA, and 4 to 8 days of no heat exposure following HA. CON performed two HSTs on average 13 days apart without heat exposure in between. HA increased WBGT_crit after nine (28.5 ± 2.7°C vs. 30.5 ± 2.0°C; <i>P</i> = 0.016) but not 5 days (28.5 ± 2.4; <i>P</i> > 0.05). No effect of HA on vT_re was observed (<i>P</i> > 0.05). Four-to-eight days post-HA, WBGT_crit and vT_re did not differ compared with 9 days of HA (<i>P</i> > 0.05). However, a reduction in vT_re (-0.4 ± 0.3 °C/h) was observed when comparing 4 to 8 days post-HA to pre-HA. In conclusion, our results demonstrate that more than 5 days of HA are required to increase WBGT_crit and indicate that 9 days of HA proceeded by adequate recovery reduced vT_re during exercise in the heat.<b>NEW & NOTEWORTHY</b> We assessed the effect of heat acclimation (HA) on critical environmental limits and rate of rectal temperature change. We show that more than 5 days of heat acclimation are required to increase critical environmental limits and that 9 days of HA proceeded by adequate recovery reduces the rate of rectal temperature change. These findings enhance our understanding of heat acclimation's effect on work capacity in the heat and may be used to design occupational guidelines.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1150-1160"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795481","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":"Greater negative affective responsivity to daily stressors is positively related to urinary norepinephrine excretion in middle-aged adults.","authors":"Elana M Gloger, Joanna H Hong, Jacqueline Mogle, David M Almeida, Jody L Greaney","doi":"10.1152/japplphysiol.00886.2024","DOIUrl":"10.1152/japplphysiol.00886.2024","url":null,"abstract":"<p><p>Despite mounting evidence that greater affective responsivity to naturally occurring daily stressors is associated with increased risk of cardiovascular diseases (CVDs), few studies have examined dysregulation of the sympathetic nervous system as a potential mechanism. We hypothesized that greater affective responsivity to daily stressful events would be related to increased urinary catecholamine excretion. Daily stress processes (8-day daily diary) were assessed in 715 middle-aged adults (56 ± 11 yr; 57% female) from the Midlife in the United States Study. Urinary norepinephrine and epinephrine concentrations were also measured (24 h; normalized to creatinine). Multilevel modeling was used to calculate negative and positive affective responsivity (i.e., the slope of the within-person differences in negative and positive affect on stressor days compared with stressor-free days). Analyses controlled for relevant covariates (e.g., sex, age, affect on stressor-free days, etc.). On stressor days, negative affect increased (0.1 ± 0.2 stressor-free days vs. 0.3 ± 0.4 au stressor days; <i>P</i> < 0.0001) and positive affect decreased (2.8 ± 0.7 stressor-free days vs. 2.6 ± 0.8 au stressor days; <i>P</i> < 0.0001). Greater negative affectivity responsivity to daily stressors was related to increased urinary norepinephrine (<i>B</i> = 0.42, SE = 0.14, <i>P</i> = 0.003), but not epinephrine (<i>P</i> = 0.142), excretion. Positive affective responsivity to daily stressors was not related to either urinary norepinephrine (<i>B</i> = -0.33, SE = 0.29, <i>P</i> = 0.24) or epinephrine (<i>P</i> = 0.626) excretion. Heightened negative affective responsivity to daily stressors was associated with greater urinary norepinephrine excretion, suggesting that sympathetic overactivation may contribute to the link between emotional vulnerability to daily stressors and increased CVD risk.<b>NEW & NOTEWORTHY</b> Few studies have examined sympathetic dysregulation as a potential mechanism linking affective responsivity to daily stressors to future cardiovascular diseases. Using a large national sample, our findings show that amplified negative affective responsivity to daily stressors is related to increased urinary norepinephrine excretion independent of the frequency of stressor occurrence. These data suggest that chronic sympathetic overactivation may contribute to the link between emotional vulnerability to daily stressors and increased risk of future cardiovascular comorbidities.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1251-1260"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982232","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":"Key determinants of impaired gait performance in adults with neuromuscular diseases: a multiparametric and multimodal analysis.","authors":"Romain Feigean, Cylia Afroun-Roca, Cloé Guerrini, Juliette Souchu, Frédéric Fer, Olivier Benveniste, Guillaume Bassez, Jean-Yves Hogrel, Damien Bachasson","doi":"10.1152/japplphysiol.00287.2024","DOIUrl":"10.1152/japplphysiol.00287.2024","url":null,"abstract":"<p><p>Neuromuscular diseases (NMD) are associated with gait impairments affecting the quality of life. Contributing factors such as the severity of muscle weakness or kinematics alterations have mostly been studied separately. Therefore, the key determinants of impaired gait in patients with NMD remain unclear. This work aimed at investigating the major determinants of gait impairments through the assessment of muscle weakness, lower limb kinematic, muscle activation, and spatiotemporal parameters within a single session in patients and controls. Patients with NMD and controls were studied. After assessing maximal voluntary strength, subjects underwent a 2-min walk test (2MWT) while recording electromyography, kinematics, perceived exertion, dyspnea, and pain using verbal scales. A penalized regression was used to identify the main contributing variable to impaired gait performance and to build a predictive model for validation; 28 with NMD and 17 controls were included. Eight major features of 2MWT gait performance were identified by the model: toe-off, stride length, step duration, cadence, ankle angle at foot strike, knee extensors strength, and timing variability in hip flexion-extension. The LASSO model provided accurate estimation of gait performance with 5.4% of average absolute error and 0.89 of <i>R</i>². Substantial alterations in muscle activation patterns and lower limb kinematics were found in patients compared with controls. This study provides insights regarding the gait impairments in patients with NMD. Identified determinants can guide targeted interventions to improve gait and quality of life. More research with larger cohorts and diverse conditions is needed to confirm and broaden these findings.<b>NEW & NOTEWORTHY</b> This is the first study aiming to identify the key determinants of impaired gait in patients with neuromuscular diseases using a comprehensive approach. Lower limb muscle activation, joint kinematics, spatiotemporal gait parameters, strength capacity and perceived stability, exertion, dyspnea, and pain were measured during a single gait session. Using a penalized regression model, 8 major determinants were identified among the 74 assessed. Delayed toe-off time was identified as the factor with the greatest relative importance.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1261-1274"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144003227","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":"Task-specific motor units in the extrinsic hand muscles control single- and multidigit tasks of the human hand.","authors":"Marius Oßwald, Andre L Cakici, Daniela Souza de Oliveira, Dominik I Braun, Dario Farina, Alessandro Del Vecchio","doi":"10.1152/japplphysiol.00911.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00911.2024","url":null,"abstract":"<p><p>Movements of the hand require a precise distribution of synaptic inputs to spinal motor neurons innervating intrinsic and extrinsic hand muscles. Humans can generate complex multidigit tasks as well as separate motions of individual digits. The specific mechanisms by which the central nervous system controls multidigit and single-digit tasks on a motor neuron level remain poorly understood. We recorded synchronized three-dimensional hand kinematics and high-density surface electromyographic data from extrinsic hand muscles, including all extrinsic thumb and digit flexors and extensors. Twelve participants each performed 13 dynamic periodic single-digit flexion and extension- and multidigit grasping tasks for 45 s per task. Multidigit tasks were composed of combinations of the performed single-digit tasks. We decoded single motor unit (MU) activity from 7.8 ± 1.8 MUs (means ± SD) per task and participant in all muscles and identified MUs across tasks. For single-digit tasks, as expected, the activity of some MUs was associated with digit kinematics (task-modulated MUs), whereas other MUs discharged in a tonic way with little modulation of their discharge rate. MUs showed task-modulated activity only for one specific single digit. Moreover, a relatively small proportion of task-modulated MUs active during single-digit tasks could be identified during the multidigit grasping tasks [median 7.5%, interquartile range (IQR) 2.2%-15.0%]. Similarly, only few task-modulated MUs were identified in more than one multidigit task (median 3.6%, IQR 0%-18.4%). These results indicate a high task specificity in the control of MUs determining hand motions.<b>NEW & NOTEWORTHY</b> We investigated the neural control of motor units in the extrinsic hand muscles during dynamic single- and multidigit movements. We consistently found motor units that modulated the generation of flexion and extension movements of individual digits. Only a small number of motor units were active in both single- and multidigit tasks. The findings suggest high neural specificity in the recruitment and modulation of discharge rates for motor units controlling single- and multidigit hand tasks.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"138 5","pages":"1187-1200"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020552","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":"The effects of acute intermittent hypercapnia on cardiovascular and ventilatory control.","authors":"Conan L H Shing, Scott F Thrall, Megan L Lance, Glen E Foster","doi":"10.1152/japplphysiol.00654.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00654.2024","url":null,"abstract":"<p><p>Acute intermittent blood-gas perturbations elicit cardiorespiratory neuroplasticity, with intermittent hypercapnic hypoxia resulting in well-characterized and persistent increases in ventilation, sympathetic activity, and blood pressure. However, the effects of intermittent hypercapnia (IHc) independent of hypoxia remain unknown in humans. We investigated the long-lasting effects of acute IHc on ventilation, blood pressure, and limb vascular conductance. Twenty-four healthy participants (age: 23 ± 3 yr; body mass index: 22 ± 2 kg/m²) underwent a 10-min baseline, 40 min of either IHc (<i>n</i> = 17; 60-s intervals: 40-s +5 mmHg end-tidal Pco₂, 20-s normocapnia) or room-air control (<i>n</i> = 7), both delivered using end-tidal forcing, followed by 30 min of room-air recovery. Minute ventilation (V̇e) and mean arterial pressure (MAP) were measured continuously, whereas arm and leg blood flow were measured via strain-gauge plethysmography at baseline and every 10 min of recovery. Limb vascular conductance (LVC) was calculated as the sum of arm and leg blood flow multiplied by two and divided by MAP. The change in ventilation from baseline was not different across 30 min of recovery (<i>P</i> = 0.09) or between groups (<i>P</i> = 0.08). MAP was elevated at 10 ([Formula: see text] 6.1 mmHg, CI_95%: 3.8-8.4, <i>P</i> < 0.001), 20 ([Formula: see text] 6.7 mmHg, CI_95%: 4.3-9.0, <i>P</i> < 0.001), and 30 ([Formula: see text] 7.7 mmHg, CI_95%: 5.4-10.0, <i>P</i> < 0.001) min of recovery and was 4.4 mmHg (CI_95%: 0.4-8.4, <i>P</i> = 0.03) greater than control throughout recovery. LVC was reduced across recovery in both groups (<i>P</i> < 0.001). These findings suggest that IHc elicits long-term facilitation of MAP with minimal effect on V̇e. These results further our understanding of intermittent hypercapnia in the regulation of the cardiorespiratory system.<b>NEW & NOTEWORTHY</b> Our findings show that in humans, intermittent hypercapnia independent of hypoxia does not appreciably affect ventilation but increases mean arterial pressure for upward of 30 min. These results help further our understanding of how repeated arterial blood gas fluctuations contribute to persistent changes in cardiovascular control.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"138 5","pages":"1217-1227"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144007535","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":"Elevated circulating endothelial cell-derived microvesicles: a biomarker of endothelial vasomotor dysfunction in adults with obesity.","authors":"Vinicius P Garcia, Hannah K Fandl, Kendra N Wegerson, Auburn R Berry, Samuel T Ruzzene, Jared J Greiner, Kelly A Stockelman, Caitlin A Dow, Andrew J Park, Brian L Stauffer, Christopher A DeSouza","doi":"10.1152/japplphysiol.00081.2025","DOIUrl":"10.1152/japplphysiol.00081.2025","url":null,"abstract":"<p><p>Endothelial cell-derived extracellular microvesicles (EMVs) have emerged as a biomarker of cardiovascular disease risk, progression, and severity. The aims were to determine <i>1</i>) if circulating EMV levels are elevated in adults with obesity and <i>2</i>) whether circulating EMVs are associated with obesity-related endothelial vasomotor dysfunction. Thirty-six sedentary, midlife adults (45-63 yr) were studied: 18 adults with normal weight (12 M/6 F; age: 56 ± 6 yr; body mass index: 23.3 ± 1.5 kg/m²) and 18 adults with obesity (12 M/6 F; 53 ± 5 yr; 31.9 ± 1.7 kg/m²). EMV (CD31⁺/42b^-) concentration in plasma was determined by flow cytometry. Forearm blood flow (FBF; via plethysmography) was assessed in response to intra-arterial infusions of acetylcholine (4.0, 8.0, and 16.0 μg/100 mL·tissue/min), sodium nitroprusside (1.0, 2.0, and 4.0 μg/100 mL·tissue/min), and the selective endothelin (ET)-1 receptor antagonist BQ-123 (ET_A receptor blockade; 100 nmol/min; for 60 min). Circulating EMVs were ∼85% higher (<i>P</i> < 0.001) in adults with obesity (147 ± 54 EMV/μL) than in adults with normal weight (79 ± 27 EMV/µL). FBF response to acetylcholine was significantly lower (∼30%) in adults with obesity (from 4.3 ± 0.9 to 10.5 ± 2.3 mL/100 mL·tissue/min) versus adults with normal weight (from 4.2 ± 0.9 to 15.1 ± 2.4 mL/100 mL·tissue/min). BQ-123 elicited a significantly greater (∼35%) increase in FBF in adults with obesity, indicative of higher ET-1-mediated vasoconstrictor tone. Circulating EMVs were inversely related with total FBF response to acetylcholine (<i>r</i> = -0.49; <i>P</i> = 0.001) and positively associated with total FBF response to BQ-123 (<i>r</i> = 0.46; <i>P</i> = 0.005). In conclusion, circulating levels of EMVs are elevated in adults with obesity and are associated with reduced endothelium-dependent vasodilation and increased ET-1-mediated vasoconstrictor tone.<b>NEW & NOTEWORTHY</b> Circulating endothelial microvesicles (EMVs) may serve as a key biomarker and mediator of vascular dysfunction in obesity. This study demonstrates that EMV levels are markedly higher in adults with obesity compared with adults with normal weight. Elevated EMVs were associated with impaired endothelial vasodilation and heightened endothelin-1-mediated vasoconstriction. These findings highlight a potential mechanistic link between obesity and cardiovascular disease risk, emphasizing the role of EMVs in vascular health.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1143-1149"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143624822","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":"High-fat diets promote hematopoietic stem cell expansion and exercise reduces myeloid skewing during maintenance hematopoiesis.","authors":"James J Vanhie, Wooseok Kim, Cole Goode, Nicolas Collao, Alice Tate, Michael De Lisio","doi":"10.1152/japplphysiol.00899.2024","DOIUrl":"10.1152/japplphysiol.00899.2024","url":null,"abstract":"<p><p>High-fat diets (HFD) and exercise (EX) exert differential impacts on hematopoietic stem and progenitor cell (HSPC) differentiation during stress hematopoiesis, in part, through alterations in the HSPC niche. However, how HFDs and EX alter HSPC differentiation during maintenance conditions remains unknown. Therefore, we examined HSPC and niche cell concentrations during maintenance hematopoiesis following a HFD and EX training intervention. Male CBA mice (<i>n</i> = 40) underwent 8 wk of HFD or control (CON) diet consumption with the latter 4 wk involving sedentary (SED) or EX training interventions. Bone marrow cells were quantified by flow cytometry, and marrow-derived HSPCs were magnetically isolated for a colony-forming unit assay. HFD mice had higher body weight, body fat percentage, and lean body mass compared with CON mice without any effect of exercise. HFD promoted HSPC and myeloid progenitor cell expansion without impacting lymphoid progenitor cells. HSPCs derived from HFD mice displayed enhanced myeloid colony formation, which was inhibited by EX. EX reduced mesenchymal stromal cell concentrations. Together, these results suggest that during maintenance hematopoiesis, EX inhibits myeloid and mesenchymal stromal cell expansion, whereas HFD opposes these effects, which is similar to their effects during stress hematopoiesis.<b>NEW & NOTEWORTHY</b> We are the first to show that exercise inhibits myeloid progenitor cell expansion and mesenchymal stromal cell concentration with high-fat diet consumption during maintenance hematopoiesis in vivo. Further, we show that exercise prevents high-fat diet-induced hematopoietic stem and progenitor cell myeloid differentiation priming. Together, our findings show an important role for exercise in regulating the maintenance of hematopoiesis under high-fat diet conditions.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1275-1283"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992180","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 exposure to oscillatory shear stress impairs endothelial function in oral contraceptive pill users across pill phases.","authors":"Lindsay A Lew, Raelisa Etwaroo, Justin Bureau, Kyra E Pyke","doi":"10.1152/japplphysiol.00033.2025","DOIUrl":"10.1152/japplphysiol.00033.2025","url":null,"abstract":"<p><p>Acute exposure to oscillatory shear stress (OSS), characterized by low mean and high retrograde shear stress, can impair endothelial function in humans. However, the majority of studies have only included men and none have assessed the impact of oral contraceptive pills (OCPs) on OSS-induced endothelial function impairment. Oxidative stress is higher in OCP users versus nonusers with the highest oxidative stress in the active pill (AP; synthetic hormone) compared to the placebo pill (PP; no synthetic hormone) phase. As oxidative stress is a key mechanism linking OSS and impaired endothelial function, we hypothesized that OCP users would experience OSS-induced impairment in endothelial function in both phases with the greatest decline occurring in the AP phase. Flow-mediated dilation (FMD; via Duplex ultrasound) was assessed before and after an OSS (30-min 70-mmHg cuff occlusion) and control condition (30-min rest) in 27 OCP users (20 ± 1 years) during the AP and PP phase of the OCP cycle. A condition × time interaction (<i>P</i> < 0.001) was detected with lower percent FMD post-OSS (Pre = 5.8 ± 2.3%; Post = 4.2 ± 2.3%) but not postcontrol (Pre = 5.3 ± 2.3%; Post = 5.4 ± 2.3%). The impact of OSS on %FMD did not differ between the AP and PP phase (phase × condition × time: <i>P</i> = 0.881). In conclusion, OCP users demonstrated a decline in FMD following acute exposure to OSS, which was not impacted by the phase of the OCP cycle. Future research should explore whether endothelial function responses to OSS vary across different hormonal statuses and types of contraceptive use.<b>NEW & NOTEWORTHY</b> Oscillatory shear stress is a proatherogenic blood flow pattern characterized by low mean and high retrograde flow. Endothelial function is impaired following exposure to oscillatory shear stress in men. This article provides the first evidence that oral contraceptive pill users experience an impairment in flow-mediated dilation following an acute exposure to oscillatory shear stress that does not differ across OCP phases.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1228-1238"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144022650","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":"Prenatal cannabinoid exposure affects central cardiorespiratory control in young male and female rats.","authors":"Luis Gustavo A Patrone, Marlusa Karlen-Amarante, Luciane H Gargaglioni, Daniel B Zoccal","doi":"10.1152/japplphysiol.00044.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00044.2025","url":null,"abstract":"<p><p>Cannabis use among pregnant women is rising globally, mainly for recreational and medical reasons to relieve symptoms like nausea, vomiting, anxiety, and insomnia. This trend is reinforced by the misconception that its natural origin guarantees safety, along with government policies promoting legalization. However, exposure to cannabinoids in utero can impact normal offspring's neurodevelopment and induce malfunctioning of various physiological systems, including the cardiorespiratory function. The present study investigated whether prenatal cannabinoid exposure disrupts the generation and control of autonomic and respiratory activities in early adulthood. Using in situ preparations of juvenile male and female rats (27-28 days old) exposed to a synthetic cannabinoid (WIN 55,212-2; 0.5 mg/kg/day, <i>n</i> = 4-9) or vehicle (<i>n</i> = 3-10) during gestation, we analyzed the activity of nerves innervating respiratory muscles and blood vessels. We noticed that females receiving WIN prenatally exhibited a reduced excitatory drive (postinspiratory activity, post-I) to laryngeal muscles under resting conditions, suggesting impaired control of upper airway patency. Moreover, males and females exposed to WIN displayed reduced post-I and abdominal expiratory motor activities during stimulation of carotid body chemoreceptors (mimicking low-oxygen situations) or exposure to high carbon dioxide levels, indicating an inability to mount appropriate reflex respiratory motor responses during blood gas disturbances. In addition, WIN-treated males showed attenuated sympathoexcitatory responses to carotid body activation or hypercapnia, evidencing a limited capacity to promote sympathetic-mediated hemodynamic changes. Thus, manipulating the fetal endocannabinoid system impacts the development of networks controlling respiratory and autonomic functions, leading to negative, long-term consequences for ventilation and cardiovascular function.<b>NEW & NOTEWORTHY</b> Cannabis use among pregnant women is rising globally; however, the impact on offspring's homeostatic physiological systems is still uncertain. We found that prenatal cannabinoid exposure impairs respiratory motor control in early adulthood. We also identified that sympathetic control is limited in juvenile males exposed to cannabinoids prenatally. Cannabinoids during pregnancy disrupt offspring's central cardiorespiratory control, highlighting the need for caution regarding cannabis use during pregnancy and its postnatal implications.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"138 5","pages":"1201-1216"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017866","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":"Quantifying altered oxygen kinetics and reducing metabolic test times for children with cerebral palsy: a dual-exponential Bayesian modeling approach.","authors":"Pavreet K Gill, J Maxwell Donelan, Katherine M Steele, Michael H Schwartz, Andrew J Ries","doi":"10.1152/japplphysiol.01013.2024","DOIUrl":"10.1152/japplphysiol.01013.2024","url":null,"abstract":"<p><p>Prior research using indirect calorimetry has shown that children with cerebral palsy (CP) exhibit significantly increased energetic costs during walking. However, metabolic testing to obtain oxygen cost is challenging. As a result, differences in oxygen uptake kinetics (V̇o₂) in CP compared with their typically developing peers remain unexplored. Step changes in work rate have been shown to result in an exponential V̇o₂ response with three distinct phases <i>1</i>) cardiodynamic, <i>2</i>) primary, and <i>3</i>) steady-state. Here, we applied a dual-exponential Bayesian model to assess the time constant of the primary phase V̇o₂ response from resting to walking in children with CP. In addition, we evaluated the model's ability to estimate steady-state V̇o₂ using shorter test durations. From a sample of 263 children with CP, the median V̇o₂ time constant was 33.1 s (5th-95th percentile range: 14.5-69.8 s), significantly longer than reported values for typically developing children (range of means: 10.2-31.6 s). Furthermore, the model accurately estimated steady-state V̇o₂ using only the first 3 min of metabolic data compared with the typical 6 min used in current clinical practice. The 3-min estimate explained >95% of the 6-min estimate variance, with <5% mean absolute error. Slower oxygen kinetics in children with CP suggest impairments in metabolic control, potentially contributing to their higher energy demands. Although the exact mechanisms remain unclear, this study provides valuable insights into the walking energetics of children with CP and presents a more efficient method for analyzing V̇o₂ for this population.<b>NEW & NOTEWORTHY</b> We used a Bayesian model to study oxygen kinetics in children with CP. First, we quantified the oxygen kinetics time constant, finding no significant differences across GMFCS, sex, or age despite slower kinetics compared with typically developing peers. Next, we validated the model's ability to estimate steady-state V̇o₂ with only 3 min of data, halving the usual testing time. This method has important implications for faster, accurate metabolic analyses in clinical and research settings.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1239-1250"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970455","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}