記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/japplphysiol.01008.2024

PubMed

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Exercise-induced increases in shear rate (SR) acutely improve peripheral endothelial function, but the presence of this mechanism in cerebral arteries remains unclear. Thus, we evaluated shear-mediated dilation of the internal carotid artery (ICA), which is an index of cerebrovascular endothelial function, before and after exercise. Shear-mediated dilation was measured with 30 s of hypercapnia in 16 young adults before and 10 min after 30 min of sitting rest (CON) or three cycling exercises on four separate days. The target exercise intensity was 80% of oxygen uptake at the ventilatory threshold. To manipulate the ICA SR during exercise, participants breathed spontaneously (ExSB, SR increase) or hyperventilated without (ExHV, no increase in SR) or with ([Formula: see text], restoration of SR increase) addition of CO2 to inspiratory air. Shear-mediated dilation was calculated as a percent increase in diameter from baseline. Doppler ultrasound measures ICA velocity and diameter. The CON trial revealed that 30 min of sitting did not alter shear-mediated dilation (4.34 ± 1.37% to 3.44 ± 1.23%, P = 0.052). ICA dilation after exercise compared with preexercise levels increased in the ExSB trial (3.32 ± 1.37% to 4.74 ± 1.84%, P < 0.01), remained unchanged in the ExHV trial (4.07 ± 1.55% to 3.21 ± 1.48%, P = 0.07), but was elevated in the [Formula: see text] trial (3.35 ± 1.15% to 4.33 ± 2.12%, P = 0.04). Our results indicate that exercise-induced increases in cerebral shear may play a crucial role in improving cerebrovascular endothelial function after acute exercise in young adults.NEW & NOTEWORTHY We found that 30-min cycling (target intensity was 80% of the ventilatory threshold) with increasing shear of the internal carotid artery (ICA) enhanced transient hypercapnia-induced shear-mediated dilation of the ICA, reflecting improved cerebrovascular endothelial function. This enhancement of ICA dilation was diminished by suppressing the exercise-induced increase in ICA shear via hyperventilation. Our results indicate that increases in cerebral shear may be a key stimulus for improving cerebrovascular endothelial function after exercise in young adults.

DOI： 10.1152/japplphysiol.00543.2023

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Abstract

Handgrip exercise (HG), a small muscle exercise, improves cognitive function and is expected to provide a useful exercise mode to maintain cerebral health. However, the effect of HG on cerebral blood flow regulation is not fully understood. The present study aimed to examine the effect of acute HG on cerebral endothelial function as one of the essential cerebral blood flow regulatory functions. Thirteen healthy young participants performed interval HG, consisting of 4 sets of 2 min HG at 25% of maximum voluntary contraction with 3 min recovery between each set. Cognitive performance was evaluated before and at 5 and 60 min after interval HG using the Go/No‐Go task (reaction time and accuracy). The diameter and blood velocity of the internal carotid artery (ICA) were measured using a duplex Doppler ultrasound system. To assess cerebral endothelial function, hypercapnia (30 s of hypercapnia stimulation, end‐tidal partial pressure of CO₂: +9 mmHg)‐induced cerebrovascular flow‐mediated dilatation (cFMD) was induced, calculated as relative peak dilatation from baseline diameter. The shear rate (SR) was calculated using the diameter and blood velocity of the ICA. As a result, cognitive performance improved only at 5 min after interval HG (reaction time, P = 0.008; accuracy, P = 0.186), whereas ICA SR during interval HG and cFMD after interval HG were unchanged (P = 0.313 and P = 0.440, respectively). These results suggest that enhancement in cerebral endothelial function is not an essential mechanism responsible for acute HG‐induced cognitive improvement.

New Findings

What is the central question of this study?

Does handgrip exercise, a small muscle exercise, improve cerebral endothelial function?

What is the main finding and its importance?

Acute interval isometric handgrip exercise (2 min of exercise at 25% maximum voluntary contraction, followed by 3 min of recovery, repeated for a total of 4 sets) did not improve cerebral endothelial function. Since the cerebrovascular shear rate did not change during exercise, it is possible that acute handgrip exercise is not sufficient stimulation to improve cerebral endothelial function.

DOI： 10.1113/ep091125

PubMed

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Postprandial hyperglycemia is assumed to have a negative impact on flow-mediated dilation (FMD), an index of endothelial function, and blood flow of the peripheral conduit arteries. This study aimed to determine whether the enhancement of postprandial hyperglycemia by skipping breakfast accelerates endothelial dysfunction and reduces the blood flow in the brachial artery in young men. METHODS: Using a randomized cross-over design, ten healthy men completed two trials: with and without breakfast (Eating and Fasting trials, respectively). Venous blood sampling and brachial FMD tests were conducted before, 30, 60, 90, and 120 min after a 75-g oral glucose tolerance test (OGTT). RESULTS: Skipping breakfast boosted post-OGTT glucose levels than having breakfast (P = 0.01). The magnitude of the decrease in FMD via OGTT did not vary between trials (main effect of trial P = 0.55). Although brachial blood flow tended to decrease after OGTT in both trials (interaction and main effect of time P = 0.61 and P = 0.054, respectively), the decrease in blood flow following OGTT was greater in the Fasting trial than in the Eating trial (main effect of trial, mean difference =  - 15.8 mL/min [95%CI =  - 25.6 to - 6.0 mL/min], P < 0.01). CONCLUSION: Skipping breakfast did not enhance the magnitude of the decrease in FMD following glucose loading, but did accelerate hyperglycemia-induced reduction in brachial blood flow. Current findings suggest that even missing one breakfast has negative impacts on the blood flow regulation of the peripheral conduit arteries in young men who habitually eat breakfast.

DOI： 10.1007/s00421-023-05273-6

PubMed

researchmap

記述言語：日本語   出版者・発行元：(一社)日本基礎理学療法学会  

医中誌

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/jcm12062441

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Intermittent- (IH), as opposed to continuous hypoxia (CH), is thought to have beneficial effects on cardiovascular function and health. In the present study we examined the acute effects of IH and CH (~80% pulse oxygen saturation via 10% oxygen tank) on peripheral vascular function. Brachial artery flow-mediated dilation (FMD) was used to assess vascular function in 12 young adults (23±5 yr; 8M/4F) before and after 50 minutes of IH [5 cycles; 4 min normoxia/6 min hypoxia per cycle], CH [20 min normoxia followed by 30 min hypoxia], or time control [50 min normoxia] interventions. Brachial artery diameter and velocity were measured using Doppler ultrasound to assess blood flow and shear rate. The total change in shear rate was greater during IH (634±1073·s-1, P<0.05) and CH (321±833·s-1, P=0.05) compared to time control (-412±789·s-1). %FMD was reduced following time control (7.4±1.2% to 5.9±1.1%, P<0.05) but was maintained following both hypoxia trials (IH: 7.2±1.5% to 7.5±1.5%, P=0.52; CH: 6.9±1.6% to 6.8±1.4%, P=0.73). Normalized %FMD for shear rate area under the curve (%FMDSRAUC) was reduced following the time control trial (4.2±1.4% to 3.7±0.9%, P<0.05) with no change observed with CH (4.0±1.5% to 3.9±1.4%, P=0.71). However, %FMDSRAUC increased with IH (3.8±1.1% to 4.5±1.5%, P<0.05). Our data suggest that acute exposure to hypoxia (both intermittently and continuously) offset the decline in vascular function following brief inactivity. The potential beneficial effect of hypoxia on peripheral vascular function observed in the current study may be associated with enhanced brachial artery shear in response to the hypoxic challenge.

DOI： 10.1152/ajpregu.00161.2022

PubMed

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00421-022-05096-x

PubMed

researchmap

担当区分：最終著者,　責任著者   記述言語：英語  

DOI： 10.1007/s00421-021-04785-3

PubMed

researchmap

記述言語：日本語   出版者・発行元：(一社)日本基礎理学療法学会  

医中誌

researchmap

記述言語：日本語   出版者・発行元：(一社)日本基礎理学療法学会  

医中誌

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Exercise-induced increases in shear rate (SR) across different exercise intensities may differentially affect hypercapnia-induced vasodilation of the internal carotid artery (ICA), a potential index of cerebrovascular function. We aimed to elucidate the effects of exercise intensity on ICA SR during exercise and post-exercise hypercapnia-induced vasodilation of the ICA in young men. METHODS: Twelve healthy men completed 30 min of cycling at moderate [MIE; 65 ± 5% of age-predicted maximal heart rate (HRmax)] and high (HIE; 85 ± 5% HRmax) intensities. Hypercapnia-induced vasodilation was induced by 3 min of hypercapnia (target end-tidal partial pressure of CO2 + 10 mmHg) and was assessed at pre-exercise, 5 min and 60 min after exercise. Doppler ultrasound was used to measure ICA diameter and blood velocity during exercise and hypercapnia tests. RESULTS: SR was not altered during either exercise (interaction and main effects of time; both P > 0.05). ICA conductance decreased during HIE from resting values (5.1 ± 1.3 to 3.2 ± 1.0 mL·min-1·mmHg-1; P < 0.01) but not during MIE (5.0 ± 1.3 to 4.0 ± 0.8 mL·min-1·mmHg-1; P = 0.11). Consequently, hypercapnia-induced vasodilation declined immediately after HIE (6.9 ± 1.7% to 4.0 ± 1.4%; P < 0.01), but not after MIE (7.2 ± 2.1% to 7.3 ± 1.8%; P > 0.05). Sixty minutes after exercise, hypercapnia-induced vasodilation returned to baseline values in both trials (MIE 8.0 ± 3.1%; HIE 6.4 ± 2.9%; both P > 0.05). CONCLUSION: The present study showed blunted hypercapnia-induced vasodilation of the ICA immediately after high-intensity exercise, but not a moderate-intensity exercise in young men. Given that the acute response is partly linked to the adaptive response in the peripheral endothelial function, the effects of aerobic training on cerebrovascular health may vary depending on exercise intensity.

DOI： 10.1007/s00421-021-04721-5

PubMed

researchmap

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study aimed to elucidate the effects of change in estrogen during the menstrual cycle and menopause on shear-mediated dilation of the internal carotid artery (ICA), a potential index of cerebrovascular endothelial function. Shear-mediated dilation of the ICA and serum estradiol were measured in 11 premenopausal (Pre-M, 21 ± 1 yr), 13 perimenopausal (Peri-M, 49 ± 2 yr), and 10 postmenopausal (Post-M, 65 ± 7 yr) women. Measurements were made twice within the Pre-M group at their early follicular (EF, lower estradiol) and late follicular (LF, higher estradiol) phases. Shear-mediated dilation was induced by 3 min of hypercapnia (target PETCO2 + 10 mmHg from individual baseline) and was calculated as the percent rise in peak diameter relative to baseline diameter. ICA diameter and blood velocity were simultaneously measured by Doppler ultrasound. In Pre-M, shear-mediated dilation was higher during the LF phase than during the EF phase (P < 0.01). Comparing all groups, shear-mediated dilation was reduced across the menopausal transition (P < 0.01), and Pre-M during the LF phase showed the highest value (8.9 ± 1.4%) compared with other groups (Pre-M in EF, 6.4 ± 1.1%; Peri-M, 5.5 ± 1.3%; Post-M, 5.2 ± 1.9%, P < 0.05 for all). Shear-mediated dilation was positively correlated with serum estradiol even after adjustment of age (P < 0.01, r = 0.55, age-adjusted; P = 0.02, r = 0.35). Collectively, these data indicate that controlling the menstrual cycle phase is necessary for the cross-sectional assessments of shear-mediated dilation of the ICA in premenopausal women. Moreover, current findings suggest that a decline in cerebrovascular endothelial function may be partly related to the reduced circulating estrogen levels in peri- and postmenopausal women.NEW & NOTEWORTHY The present study evaluated the effects of the menstrual cycle and menopause stages on the shear-mediated dilation of the ICA, a potential index of cerebrovascular endothelial function, in pre-, peri-, and postmenopausal women. Shear-mediated dilation of the ICA was increased from the low- to high-estradiol phases in naturally cycling premenopausal women and was reduced with advancing menopause stages. Furthermore, lower estradiol was associated with reduced shear-mediated dilation of the ICA, independent of age.

DOI： 10.1152/ajpheart.00810.2020

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Interval exercise has been determined to be more effective than continuous exercise for achieving improvement in the cardiovascular function of individuals suffering from cardiovascular disease. However, whether interval exercise improves the cerebrovascular function remains unclear. As per our hypothesis, interval exercise induces a higher cerebrovascular shear rate (SR) than continuous exercise. In this study, 11 adult men randomly performed continuous exercise for 12 min or work-equivalent (57.6 kJ/exercise session) interval exercise of semi-recumbent cycling. The SR in the internal carotid artery (ICA) represents an index of the cerebrovascular SR, which was measured during both the exercises using Doppler ultrasonography. Both the aerobic exercise modes increased the ICA SR. Moreover, the average ICA SR of the interval exercise for the final 4 min of exercise or 2 min of recovery was significantly higher than that for continuous exercise (exercise, 351 ± 75 vs. 330 ± 61/s, p = .038; recovery, 327 ± 86 vs. 290 ± 56/s, p = .014). To our knowledge, this is the first study to show that aerobic interval exercise increased the ICA SR more than equivalent work volume of aerobic continuous exercise. Thus, aerobic interval exercise may be more effective at stimulating the cerebrovasculature, resulting in greater improvements in cerebrovascular function as compared to continuous aerobic exercise in healthy adult men. These findings provide some important information that would help enhance exercise therapy programs for patients with arteriosclerosis, especially in the cerebral circulation.

DOI： 10.14814/phy2.14705

PubMed

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1113/EP089174

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The balance of angiogenic factors, including vascular endothelial growth factor (VEGF), and angiostatic factors, like thrombospondin-1 (TSP-1) and endostatin, controls striated muscle angiogenic responses to exercise training. The effect of age on circulating levels of these factors following a bout of exercise is unclear. The authors hypothesized that older adults would have lower circulating VEGF but higher TSP-1 and endostatin after exercise compared with young adults. Ten young and nine older participants cycled for 45 min at 60% estimated HRmax. Serum [VEGF], [TSP-1], and [endostatin] obtained before (PREX), immediately after (POSTX0), and 3 hr after (POSTX3) exercise were analyzed. [VEGF] increased in older adults only from PREX to POSTX0 (p < .05). [TSP-1] increased in both age groups (p < .05). There was no effect of age or exercise on [endostatin]. In conclusion, immediately after exercise, both groups had a similar increase in [TSP-1], but [VEGF] increased in older adults only.

DOI： 10.1123/japa.2020-0024

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpheart.00532.2020

PubMed

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cyclic intermittent hypoxia (IH) increases cerebral blood velocity. This enhanced velocity augments the commensurate shear stimulus and may subsequently increase cerebrovascular endothelial function. This study aimed to examine the effects of cyclic IH on hypercapnia-induced shear-mediated dilation of the internal carotid artery (ICA), a potential index of cerebrovascular endothelial function. Shear-mediated dilation was measured in nine adults (22 ± 4 yr) before as well as after 50 min of cyclic IH [5 cycles, 4 min of normoxia, followed by 6 min of hypoxia (target 80% [Formula: see text]) per cycle] and control normoxia (sham, 50 min of continuous normoxia) on separate days (≥72 h apart). ICA diameter and velocity were measured using Doppler ultrasound during cyclic IH and hypercapnia. Shear-mediated dilation was induced by 3 min of hypercapnia (Δ[Formula: see text]; IH: pre 10.1 ± 1.0 mmHg, post 10.8 ± 1.3 mmHg; sham: pre 10.5 ± 1.5 mmHg, post 10.8 ± 1.5 mmHg) and was calculated as the percent rise in peak relative to baseline diameter. Hypoxia increased ICA blood flow and shear rate (SR) during each cycle [blood flow: 322 ± 90 to 406 ± 74 mL/min, P < 0.01; SR: 179 ± 42 to 207 ± 55/s, P = 0.06, baseline to hypoxia (average of last minute of each cycle)], which was normalized during the succeeding normoxic period (blood flow: 322 ± 90 to 329 ± 68 mL/min, P = 0.54, SR: 179 ± 42 to 176 ± 32/s, P = 0.56). As such, shear-mediated dilation increased following cyclic IH (4.6 ± 1.3% to 6.2 ± 2.2%, P < 0.01), but not control normoxia (4.9 ± 1.4% to 4.9 ± 1.4%, P = 0.92). Our data indicate that increased blood flow and SR during cyclic IH enhance shear-mediated dilation of the ICA in young adults. These results suggest that cyclic IH could be used to optimize cerebral vascular health.NEW & NOTEWORTHY We explored the effects of cyclic intermittent hypoxia (IH) on shear-mediated dilation of the internal carotid artery (ICA), a potential index of cerebral endothelial function, in young adults. Cyclic IH increased blood flow and shear rate in the ICA and, as a result, increased shear-mediated dilation of the ICA. These data suggest that cyclic IH could potentially be applied as a nonpharmacological therapy to optimize cerebral vascular health.

DOI： 10.1152/japplphysiol.00274.2020

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Consumption of a single, sugar-sweetened beverage (SSB) impairs vascular endothelial function. Regular aerobic exercise improves endothelium-dependent vasodilation; however, it is unknown whether these beneficial effects persist with frequent SSB consumption. Therefore, the purpose of this study was twofold; we studied the effects of repetitive SSB consumption (75 g d-glucose, 3 times/day) for 1 wk (Glu, n = 13, 23 ± 4 yr, 23.5 ± 3.4 kg/m2) on endothelium-dependent vasodilation (FMD). Then, in a separate cohort, we investigated whether 45 min of moderate-intensity aerobic exercise on five separate days offset the hypothesized decrease in FMD during the Glu protocol (Glu+Ex, n = 11, 21 ± 3 yr, 23.8 ± 2.4 kg/m2). Baseline, fasting [glucose] (P = 0.15), [insulin] (P = 0.25), %FMD (P = 0.48), absolute FMD (P = 0.66), and shear rate area under the curve (SRAUC; P = 0.82) were similar between groups. Following the interventions, fasting [glucose] (Glu: 94 ± 6 to 92 ± 6 mg/dL, Glu+Ex: 89 ± 8 to 87 ± 6 mg/dL, P = 0.74) and [insulin] (Glu: 11.3 ± 6.2 to 11.8 ± 8.9 μU/mL, Glu+Ex: 8.7 ± 2.9 to 9.4 ± 3.2 μU/mL, P = 0.89) were unchanged. %FMD was reduced in Glu (6.1 ± 2.2 to 5.1 ± 1.3%) and increased in Glu+Ex (6.6 ± 2.2 to 7.8 ± 2.4%, P < 0.05 for both). SRAUC increased similarly in both Glu [17,715 ± 8,275 to 22,922 ± 4,808 arbitrary units (A.U.)] and Glu+Ex (18,216 ± 4,516 to 21,666 ± 5,392 A.U., main effect of time P < 0.05). When %FMD was adjusted for SRAUC, attenuation was observed in Glu (0.41 ± 0.18 to 0.23 ± 0.08%/s × 103, P < 0.05) but not Glu+Ex (0.38 ± 0.14 to 0.38 ± 0.13%/s × 103, P = 0.88). Despite unchanged fasting [glucose] and [insulin], repeated consumption of SSBs impaired conduit artery vascular endothelial function. Additionally, subjects who engaged in regular moderate-intensity aerobic exercise did not demonstrate the same SSB-induced endothelial dysfunction. Collectively, these data suggest aerobic exercise may offset the deleterious effects of repetitive SSB consumption.

DOI： 10.1152/ajpregu.00055.2020

PubMed

researchmap

記述言語：日本語   出版者・発行元：(公財)明治安田厚生事業団  

医中誌

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In the present study, we hypothesized that habitual cigarette smoking attenuates endothelial function in the cerebral circulation as well as that of the peripheral circulation in young adults. To test this hypothesis, we measured cerebrovascular and peripheral flow-mediated dilation (FMD) in young smokers and nonsmokers in the present study. Ten healthy nonsmokers and 10 smokers participated in the study. We measured blood velocity and diameter in the brachial artery and internal carotid artery (ICA) using Doppler ultrasound. We identified shear-mediated dilation in the brachial artery and ICA by the percentage change in peak diameter during hyperemia stimulation (reactive hyperemia and hypercapnia). We measured the baseline diameter and the shear rate area under the curve from the onset of hyperemia to peak dilation in the brachial artery and ICA, finding the measurements of the smokers and those of the nonsmokers did not differ (p > .05). In contrast to brachial FMD (5.07 ± 1.79% vs. 7.92 ± 3.01%; smokers vs. nonsmokers, p = .019), FMD in the ICA was not attenuated in the smokers compared with that of the nonsmokers (5.46 ± 2.32% vs. 4.57 ± 2.70%; p = .442). These findings indicate that in young healthy smokers, cerebral endothelial function was preserved, and the response of cerebral endothelial function to smoking was different from that of peripheral vasculature.

DOI： 10.14814/phy2.14369

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: This study aimed to test our hypothesis that acute hypotension attenuates brachial flow-mediated dilation (FMD) as an index of endothelial function in healthy humans. METHODS: Twelve healthy men (21.8 ± 1.6 years, body mass index; 22.2 ± 1.6 kg/m2) participated in this study. Brachial FMD was measured in three trials: standardized FMD protocol (control trial), abrupt decrease in blood pressure (BP) via thigh cuff inflation-deflation (hypotension trial) and decrease in shear rate (SR) via a shortened forearm occlusion time (SR reduction trial). Brachial diameter and blood velocity were measured using Duplex ultrasound. RESULTS: Mean arterial pressure during reactive hyperaemia showed a marked decrease in the hypotension trial (- 23.7 ± 6.0 mmHg), but not in the control and SR reduction trials. SR area under the curve was attenuated in the SR reduction trial (P < 0.001), but not in the control and hypotension trials (P = 0.316). Consequently, FMD was attenuated in the hypotension and SR reduction trials compared with that in the control trial (P = 0.003 and P = 0.043, respectively), and was attenuated to a greater extent in the hypotension trial compared with the SR reduction trial (P = 0.006; control, 6.9 ± 3.5%; hypotension, 3.5 ± 1.7%; SR reduction, 5.0 ± 2.2%). After adjusting FMD using SR, FMD remained attenuated in the hypotension trial (P = 0.014), but not in the SR reduction trial. CONCLUSION: Our findings indicate that arterial pressure as well as sympathetic nervous system activation could be an important determinant of FMD. Blunted FMD of peripheral arteries may be a rational response to restore BP and/or prevent further reduction of BP following acute hypotension in healthy humans.

DOI： 10.1007/s00421-019-04260-0

PubMed

researchmap

記述言語：日本語   出版者・発行元：(一社)日本基礎理学療法学会  

その他リンク： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2019&ichushi_jid=J05805&link_issn=&doc_id=20191227260008&doc_link_id=%2Fch1thrpy%2F2019%2F002201%2F008%2F0054-0062%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fch1thrpy%2F2019%2F002201%2F008%2F0054-0062%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

医中誌

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We hypothesized that respiratory muscle endurance training (RMET) in hypoxia induces greater improvements in respiratory muscle endurance with attenuated respiratory muscle metaboreflex and consequent whole-body performance. We evaluated respiratory muscle endurance and cardiovascular response during hyperpnoea and whole-body running performance before and after RMET in normoxia and hypoxia. METHODS: Twenty-one collegiate endurance runners were assigned to control (n = 7), normoxic (n = 7), and hypoxic (n = 7) groups. Before and after the 6 wk of RMET, incremental respiratory endurance test and constant exercise tests were performed. The constant exercise test was performed on a treadmill at 95% of the individual's peak oxygen uptake (V˙O2peak). The RMET was isocapnic hyperpnoea under normoxic and hypoxic conditions (30 min·d). The initial target of minute ventilation during RMET was set to 50% of the individual maximal voluntary ventilation, and the target increased progressively during the 6 wk. Target arterial oxygen saturation in the hypoxic group was set to 90% in the first 2 wk, and thereafter it was set to 80%. RESULTS: Respiratory muscle endurance was increased after RMET in the normoxic and hypoxic groups. The time to exhaustion at 95% V˙O2peak exercise also increased after RMET in the normoxic (10.2 ± 2.4 to 11.2 ± 2.6 min) and hypoxic (11.5 ± 2.6 to 12.6 ± 3.0 min) groups, but not in the control group (9.6 ± 3.2 to 9.4 ± 4.0 min). The magnitude of these changes did not differ between the normoxic and the hypoxic groups (P = 0.84). CONCLUSION: These results suggest that the improvement of respiratory muscle endurance and blunted respiratory muscle metaboreflex could, in part, contribute to improved endurance performance in endurance-trained athletes. However, it is also suggested that there are no additional effects when the RMET is performed in hypoxia.

DOI： 10.1249/MSS.0000000000001929

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Brain-derived neurotrophic factor (BDNF) plays several important roles in nervous system function including neuronal growth and plasticity. The purpose of the present study was to clarify whether neuromuscular electrical stimulation (NMES) and voluntary exercise to the same integrated force as by the NMES-induced exercise would enhance serum BDNF. Eleven healthy male subjects completed three interventions (NMES, voluntary exercise, and resting interventions) for 20 min on different days. In the NMES intervention, NMES was applied to the quadriceps femoris muscles. The stimulus intensity of NMES was progressively increased to the highest tolerated intensity during the experiment. In the voluntary exercise intervention, subjects performed an isometric knee-extension task; in this intervention, the target torque was calculated in accordance with the integrated force of knee extension obtained during the NMES intervention. In the resting intervention, subjects relaxed in a sitting posture. We measured serum BDNF, blood lactate, heart rate, oxygen uptake, respiratory ratio, and blood pressure. Serum BDNF was increased in the NMES (p = 0.003) and voluntary exercise interventions (p = 0.004) after each intervention. At the post-timepoint, serum BDNF in the NMES intervention was highest among all interventions (p = 0.038) and significantly higher than in the voluntary exercise (p = 0.036) and resting (p = 0.037) interventions. Our results showed that NMES was more effective for enhancing serum BDNF than voluntary exercise at least when employing the same method and integrated force.

DOI： 10.1007/s00221-018-5396-y

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study aimed to elucidate the effect of aging on shear-mediated dilation of the common and internal carotid arteries (CCA and ICA, respectively). Hypercapnia-induced shear-mediated dilation in the CCA and ICA were assessed in 10 young (5 women and 5 men, 23 ± 1 yr) and 10 older (6 women/4 men, 68 ± 1 yr) healthy adults. Shear-mediated dilation was induced by two levels of hypercapnia (target end-tidal Pco2, +5 and +10 mmHg from individual baseline values) and was calculated as the percent rise in peak diameter from baseline diameter. There were no differences in shear-mediated dilation between young and older adults in either artery under lower levels of hypercapnia (CCA: 2.8 ± 0.6 vs. 2.0 ± 0.3%, P = 0.35; ICA: 4.6 ± 0.8 vs 3.6 ± 0.4%, P = 0.37). However, shear-mediated dilation in response to higher levels of hypercapnia was attenuated in older compared with young adults in the ICA (4.5 ± 0.5 vs. 7.9 ± 1.2%, P < 0.01) but not in the CCA (3.7 ± 0.6 vs. 4.5 ± 0.8%, P = 0.35). Shear-mediated dilation was significantly correlated to the percent change in shear rate in the ICA (young: r = 0.55, P = 0.01; older: r = 0.49, P = 0.03) but not in the CCA in either young or older adults (young: r = -0.30, P = 0.90; older: r = 0.16, P = 0.50). These data indicate that aging attenuates shear-mediated dilation of the ICA in response to higher levels of hypercapnia, and shear rate is an important stimulus for hypercapnic vasodilation of the ICA in both young and older adults. The present results may provide insights into age-related changes in the regulation of cerebral circulation in healthy adults. NEW & NOTEWORTHY We explored the effect of aging on shear-mediated dilation in the common and internal carotid arteries (CCA and ICA, respectively) in healthy adults. Our findings suggest that 1) aging attenuates shear-mediated dilation of the ICA but not the CCA and 2) shear rate is an important stimulus for hypercapnic vasodilation of the ICA in young and older adults. These findings may provide insights into the age-related changes in cerebrovascular regulation of healthy adults.

DOI： 10.1152/ajpheart.00335.2018

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1113/JP275777

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physiological Society  

DOI： 10.1152/japplphysiol.01011.2017

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Habitual aerobic exercise attenuates elevated vasoconstriction during acute exercise (functional sympatholysis) in older men; however, this effect remains unknown in postmenopausal women (PMW). This study tested the hypothesis that PMW who participate in habitual aerobic exercise demonstrate a greater functional sympatholysis compared with their untrained counterparts. Nineteen PMW (untrained n = 9 vs. trained n = 10) performed 5 min of steady-state (SS) forearm exercise at relative [10% and 20% of maximum voluntary contraction (MVC)] and absolute (5 kg) contraction intensities. Lower-body negative pressure (LBNP) was used to increase sympathetic vasoconstriction during rest and forearm exercise. Brachial artery diameter and blood velocities (via Doppler ultrasound) determined forearm blood flow (FBF; ml/min). Forearm muscle oxygen consumption ([Formula: see text]; ml/min) and arteriovenous oxygen difference (a-vO2diff) were estimated during SS-exercise and SS-exercise with LBNP. Forearm vascular conductance (FVC; ml·min-1·100 mmHg-1) was calculated from FBF and mean arterial pressure (MAP; mmHg). Vasoconstrictor responsiveness was determined as the %change in FVC during LBNP. The reduction in FVC (% change FVC) during LBNP was lower in trained compared with untrained PMW at 10% MVC (-7.3 ± 1.2% vs. -13.0 ± 1.1%; P < 0.05), 20% MVC (-4.4 ± 0.8% vs. -8.6 ± 1.4%; P < 0.05), and 5 kg (-5.3 ± 0.8% vs. -8.9 ± 1.4%; P < 0.05) conditions, whereas there were no differences at rest (-32.7 ± 4.4% vs. -33.7 ± 4.0%). Peripheral (FVC, FBF, and [Formula: see text]) and the magnitude change in systemic hemodynamics (heart rate and MAP) did not differ between groups during exercise. Collectively, the findings present the first evidence suggesting that PMW who participate in aerobic exercise demonstrate a greater functional sympatholysis compared with untrained PMW during mild to moderate forearm exercise. NEW & NOTEWORTHY Habitual aerobic exercise attenuates the elevated sympathetic nervous system-induced vasoconstriction during an acute bout of exercise (improved functional sympatholysis) in aging men; however, this effect remains unknown in postmenopausal women (PMW). The novel findings of this study suggest that habitual aerobic exercise results in an enhanced functional sympatholysis in PMW. Conversely, habitual aerobic exercise does not alter blood flow and oxygen utilization during acute forearm exercise compared with PMW who do not habitually exercise.

DOI： 10.1152/japplphysiol.00411.2017

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Lippincott Williams and Wilkins  

DOI： 10.1249/MSS.0000000000001405

PubMed

researchmap

記述言語：日本語   出版者・発行元：(一社)理学療法科学学会  

その他リンク： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J02929&link_issn=&doc_id=20170425450017&doc_link_id=%2Fca8ryoho%2F2017%2F003202%2F017%2F0249-0254%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fca8ryoho%2F2017%2F003202%2F017%2F0249-0254%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

医中誌

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physiological Society  

DOI： 10.14814/phy2.13046

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.resp.2016.04.010

PubMed

Web of Science

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cell division, a prerequisite for cell proliferation, is a process in which each daughter cell inherits one complete set of chromosomes. The mitotic spindle is a dedicated apparatus for the alignment and segregation of chromosomes. Extracellular signal-regulated kinase (ERK) 1/2 plays crucial roles in cell cycle progression, particularly during M-phase. Although, association with the mitotic spindle has been reported, the precise roles played by ERK in the dynamics of the mitotic spindle and in M-phase progression remain to be elucidated. In this study, we used MEK inhibitors U0126 and GSK1120212 to dissect the roles of ERK in M-phase progression and chromosome alignment. Fluorescence microscopy revealed that ERK is localized to the spindle microtubules in a manner independent of Src kinase, which is one of the kinases upstream of ERK at mitotic entry. ERK inhibition induces an increase in the number of prophase cells and a decrease in the number of anaphase cells. Time-lapse imaging revealed that ERK inhibition perturbs chromosome alignment, thereby preventing cells from entering anaphase. These results suggest that ERK plays a role in M-phase progression by regulating chromosome alignment and demonstrate one of the mechanisms by which the aberration of ERK signaling may produce cancer cells.

DOI： 10.1002/jcb.25424

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/cpf.12194

PubMed

Web of Science

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physiological Society  

DOI： 10.14814/phy2.12423

PubMed

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00421-013-2694-8

PubMed

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpregu.00489.2012

PubMed

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The purpose of this study was to clarify the effect of acute exercise in hypoxia on flow-mediated vasodilation (FMD). Eight males participated in this study. Two maximal exercise tests were performed using arm cycle ergometry to estimate peak oxygen uptake [Formula: see text] while breathing normoxic [inspired O(2) fraction (FIO(2)) = 0.21] or hypoxic (FIO(2) = 0.12) gas mixtures. Next, subjects performed submaximal exercise at the same relative exercise intensity [Formula: see text] in normoxia or hypoxia for 30 min. Before (Pre) and after exercise (Post 5, 30, and 60 min), brachial artery FMD was measured during reactive hyperemia by ultrasound under normoxic conditions. FMD was estimated as the percent (%) rise in the peak diameter from the baseline value at prior occlusion at each FMD measurement (%FMD). The area under the curve for the shear rate stimulus (SR(AUC)) was calculated in each measurement, and each %FMD value was normalized to SR(AUC) (normalized FMD). %FMD and normalized FMD decreased significantly (P < 0.05) immediately after exercise in both condition (mean ± SE, FMD, normoxic trial, Pre: 8.85 ± 0.58 %, Post 5: -0.01 ± 1.30 %, hypoxic trial, Pre: 8.84 ± 0.63 %, Post 5: 2.56 ± 0.83 %). At Post 30 and 60, %FMD and normalized FMD returned gradually to pre-exercise levels in both trials (FMD, normoxic trial, Post 30: 1.51 ± 0.68 %, Post 60: 2.99 ± 0.79 %; hypoxic trial, Post 30: 4.57 ± 0.78 %, Post 60: 6.15 ± 1.20 %). %FMD and normalized FMD following hypoxic exercise (at Post 5, 30, and 60) were significantly (P < 0.05) higher than after normoxic exercise. These results suggest that aerobic exercise in hypoxia has a significant impact on endothelial-mediated vasodilation.

DOI： 10.1007/s00421-012-2442-5

PubMed

researchmap

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1249/MSS.0b013e31824294f9

PubMed

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpregu.00006.2012

PubMed

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpregu.00119.2011

PubMed

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.resp.2010.06.002

PubMed

Web of Science

researchmap

記述言語：日本語   出版者・発行元：日本基礎理学療法学会学術誌局  

その他リンク:： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2016&ichushi_jid=J05805&link_issn=&doc_id=20161128310005&doc_link_id=%2Fch1thrpy%2F2016%2F001902%2F005%2F0029-0038%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fch1thrpy%2F2016%2F001902%2F005%2F0029-0038%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

医中誌

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

DOI： 10.1249/01.mss.0000485587.76585.f6

PubMed

Web of Science

researchmap

記述言語：日本語   出版者・発行元：日本基礎理学療法学会学術誌局  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

researchmap

記述言語：日本語   出版者・発行元：(一社)日本心臓病学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本心臓病学会  

医中誌

researchmap

記述言語：日本語   出版者・発行元：日本運動療法学会  

医中誌

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

DOI： 10.1249/01.mss.0000478755.75605.c1

Web of Science

researchmap

記述言語：日本語   出版者・発行元：(公社)全国大学保健管理協会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(公社)全国大学保健管理協会  

医中誌

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：日本語   出版者・発行元：名古屋大学総合保健体育科学センター  

DOI： 10.18999/njhpfs.37.1.53

researchmap

記述言語：日本語   出版者・発行元：The Japanese Society of Physical Fitness and Sports Medicine  

DOI： 10.7600/jspfsm.63.113

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：杏林書院  

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

DOI： 10.7600/jspfsm.62.622

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

DOI： 10.7600/jspfsm.62.527

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：Japan Society of Exercise and Sports Physiology  

その他リンク:： https://projects.repo.nii.ac.jp/?action=repository_uri&item_id=194391

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

DOI： 10.7600/jspfsm.61.597

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

DOI： 10.7600/jspfsm.61.754

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：日本語   出版者・発行元：石本記念デサントスポーツ科学振興財団事務局  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(公財)明治安田厚生事業団  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(公社)全国大学保健管理協会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(公社)全国大学保健管理協会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

Web of Science

researchmap

記述言語：英語   出版者・発行元：Japan Society of Exercise and Sports Physiology  

その他リンク:： https://projects.repo.nii.ac.jp/?action=repository_uri&item_id=194266

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(NPO)日本臨床運動療法学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本生理人類学会  

DOI： 10.20718/jjpa.15.1_1

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本体力医学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：理学療法科学学会  

〔目的〕嚥下前後の呼吸コントロールが飲み込みやすさに与える影響を明らかにする。〔対象〕健常成人22名とした。〔方法〕自由嚥下および嚥下前後の4つの呼吸位相パターンでの嚥下中の舌骨上筋群活動量と時間，喉頭運動時間，および主観的飲み込みやすさを測定した。〔結果〕指示嚥下では，自由嚥下と比較して，喉頭運動時間には有意差が認められなかったが，舌骨上筋群筋活動量は有意に低値を示した。主観的飲み込みやすさは，指示嚥下と自由嚥下間に有意差が認められ，指示嚥下内での比較では嚥下前が呼気であると高値を示した。〔結語〕指示嚥下は，自由嚥下と比較すると，主観的には飲み込みにくくなるが，効率よく嚥下ができる可能性があり，その中で，嚥下前後に呼気コントロールを行うことが，主観的にも飲み込みやすいパターンになることが示唆された。<br>

DOI： 10.1589/rika.24.381

researchmap

記述言語：日本語   出版者・発行元：理学療法科学学会  

DOI： 10.1589/rika.24.381

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(NPO)日本臨床運動療法学会  

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本理学療法士学会  

DOI： 10.15063/rigaku.KJ00005931382

医中誌

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(一社)日本呼吸ケア・リハビリテーション学会  

医中誌

J-GLOBAL

researchmap

researchmap

researchmap

researchmap

researchmap