Education 【 display / non-display 】

Education 【 display / non-display 】

• 2010

  -

  2013

  Nagoya University   医学系研究科 短縮修了（医学博士）  

• 2008

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  2010

  Hiroshima University   保健学研究科 修了（保健学修士）  

Degree 【 display / non-display 】

Degree 【 display / non-display 】

• 名古屋大学   博士（医学）

Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2024.04

  -

  Now

  札幌医科大学 保健医療学部 理学療法学科   准教授

• 2020.04

  -

  2024.03

  Sapporo Medical University   School of Health Sciences   講師

• 2019.10

  -

  2019.12

  University of Iowa, Human Integrative and Cardiovascular Physiology Laboratory  

• 2016.09

  -

  2017.09

  University of Iowa   Human Integrative and Cardiovascular Physiology Laboratory  

• 2013.04

  -

  2020.03

  Sapporo Medical University   助教

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Professional Memberships 【 display / non-display 】

Professional Memberships 【 display / non-display 】

• 　

  　

  　

  THE JAPANESE SOCIETY OF PHYSICAL FITNESS AND SPORTS MEDICINE

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  JAPANESE PHYSICAL THERAPY ASSOCIATION

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  American College of Sports Medicine

• 　

  　

  　

  American Physiological Society

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  日本基礎理学療法学会

Research Areas 【 display / non-display 】

Research Areas 【 display / non-display 】

• Life sciences   Sports science  

• Life sciences   Rehabilitation science  

Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• University of Iowa / Human Integrative and Cardiovascular Physiology Laboratory   Visiting scholar  

• Sapporo Medical University   School of Health Sciences   准教授  

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

• Hypoxia

• 内部障害リハビリテーション

• locomotor-respiratory coordination

• Blood flow

• Exercise program

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Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Effects of inspiratory muscle metaboreflex on cerebral circulation at rest and during light-intensity exercise in healthy males.

  Kohei Sato, Tatsuki Kamoda, Rintaro Sakamoto, Keisho Katayama, Toru Neki, Masaki Katayose, Erika Iwamoto

  Respiratory physiology & neurobiology   336   104422 - 104422  2025.03  [International journal]

  Authorship：   Last author  , Corresponding author

  　View Summary

  PURPOSE: This study aimed to clarify the effects of inspiratory muscle metaboreflex on cerebral circulation at rest and during exercise. METHODS: Twelve young males randomly completed two trials (rest and exercise [leg cycling at 40% peak oxygen uptake] trials) on separate days. In each trial, the internal carotid artery (ICA), an index of cerebral circulation, was measured using Doppler ultrasound 2min after inspiratory loading breathing (IL condition) or non-loading breathing (control condition). During ICA assessments, participants engaged in 3min of spontaneous breathing (SB), followed by 3min of isocapnic hyperventilation (IHV). RESULTS: ICA conductance was lower in the IL condition than in the control condition in both rest and exercise trials. Inspiratory mucle metaboreflex did not reduce ICA blood flow during SB but decreased it during IHV in both trials. CONCLUSION: Our findings suggest that inspiratory muscle metaboreflex could decrease cerebrovascular conductance from rest to light-intensity exercise and attenuates cerebral blood flow with increased respiratory muscle work.

  DOI PubMed

• Dilatory responsiveness of the internal carotid artery to shear stimulus is constant under different levels of transient hypercapnia.

  Rintaro Sakamoto, Tatsuki Kamoda, Shigehiko Ogoh, Kohei Sato, Masaki Katayose, Toru Neki, Erika Iwamoto

  Journal of applied physiology (Bethesda, Md. : 1985)   138 ( 2 ) 397 - 403  2025.02  [International journal]

  Authorship：   Last author  , Corresponding author

  　View Summary

  Peripheral endothelial function, which accounts for the variability in shear stimulus, can be assessed using shear-mediated dilation normalized to the increased shear stimulus. Similarly, shear-mediated dilation of the internal carotid artery (ICA), an index of cerebrovascular endothelial function, should be normalized to increased shear stimulus. However, this approach has not yet been validated. Thus, the shear-mediated dilation of the ICA was assessed in 14 young adults during three levels of transient hypercapnia, induced by elevating the partial pressure of end-tidal carbon dioxide for 30 s by 6, 9, and 12 mmHg. The ICA shear rate (SR) was calculated using the ICA diameter and velocity, both measured by Doppler ultrasound. The total vasodilator stimulus was quantified as the SR area under the curve from the onset of hypercapnia to peak dilation, including and excluding baseline values [(SRAUC) and delta SRAUC (DSRAUC), respectively]. Shear-mediated dilation was calculated as the percent increase in diameter from baselines. ICA dilation was positively associated with DSRAUC [r(rm) = 0.47, P < 0.01] but not with SRAUC [r(rm) = 0.32, P = 0.09]. Consequently, ICA dilation normalized to DSRAUC did not differ among trials (main effect of rial, P = 0.77). Contrarily, the difference in ICA dilation among trials remained significant when normalized to SRAUC (main effect of trial, P = 0.02). Therefore, normalized shear-mediated dilation using DSRAUC can reduce variability associated with increased shear stimulus during ICA dilation assessment, thereby enhancing the validity of evaluating cerebrovascular endothelial function.NEW & NOTEWORTHY This study demonstrated that shear-mediated dilation of the internal carotid artery (ICA), an index of cerebrovascular endothelial function, increased with the increase of shear stimulus induced by different degrees of transient hypercapnia. However, when ICA dilation was normalized to the total increased shear stimulus above baseline, the vasodilation became comparable across different hypercapnia levels. Thus, normalizing ICA dilation to the total shear stimulus increased from baseline may enhance the validity of assessing cerebrovascular endothelial function.

  DOI PubMed

• Prolonged sitting is not associated with altered shear-mediated dilation of the internal carotid artery, despite impairing lower limb endothelial function.

  Shotaro Saito, Kento Dora, Marino Karaki, Narumi Kunimatsu, Hayato Tsukamoto, Jun Sugawara, Erika Iwamoto, Shigehiko Ogoh

  Physiological reports   13 ( 3 ) e70097  2025.02  [International journal]

  　View Summary

  The present study aims to examine the effect of 4 h of continuous sitting on cerebral endothelial function, which is a crucial component of cerebral blood flow regulation. We hypothesized that 4 h of sitting may impair cerebral endothelial function similarly to how it affects lower limb vasculature. Thirteen young, healthy participants were instructed to remain seated for 4 h without moving their lower limbs. The blood flow and shear rate (SR) in the popliteal and internal carotid artery (ICA) were measured using duplex Doppler ultrasound. During the 4-h sitting, peripheral (popliteal artery) and cerebral (ICA) endothelial function were assessed every hour. We induced peripheral and cerebral flow-mediated dilation (pFMD and ICA FMD) using hyperemia (5 min of cuff inflation on lower limb, then deflation) or hypercapnia (30s of hypercapnia, end-tidal partial pressure of CO2 + 9 mmHg), respectively. We then calculated each relative peak dilation from the baseline diameter to identify both pFMD and ICA FMD. We observed a significant decrease in pFMD starting at 2 h from the onset of sitting, and this reduction persisted throughout the 4-h sitting [Base (6.8 ± 4.2%) vs. 2-h (3.9 ± 2.0%), p = 0.044; vs. 3-h (3.2 ± 1.8%), p = 0.016; vs. 4-h (3.2 ± 1.9%), p = 0.005]. In contrast, during the 4-h sitting, ICA blood flow, SR, and ICA FMD remained unchanged (p = 0.062, p = 0.068, and p = 0.203, respectively). Unlike peripheral endothelial function, cerebral endothelial function remained stable during 4-h sitting. This suggests that the acute effect of prolonged sitting on cerebral vasculature differs from that of lower limb vasculature.

  DOI PubMed

• inhibition of sympathetic vasomotor outflow during low-intensity leg cycling is attenuated in heathy older females

  Katayama K., Shiozawa K., Ishida K., Banno R., Kinoshita A., Iwamoto E., Ogoh S.

  J. Appl. Physiol.   138 ( 5 ) 1133 - In press  2025  [International journal]

  　View Summary

  The purpose of the present study was to elucidate the impact of age on muscle sympathetic nerve activity (MSNA) during dynamic leg exercise in females. Nine older females (71 ± 2 yr, means ± SD) and ten younger females (21 ± 2 yr) completed the study. The participants performed two 4-min leg cycling at 10% of their heart rate reserve using a cycle ergometer in a semirecumbent position [MSNA and estimated central venous pressure (eCVP) trials]. MSNA was recorded via microneurography of the left radial nerve. The CVP was estimated based on peripheral venous pressure, which was monitored using a cannula in the right antecubital vein. The magnitude of the change in mean arterial blood pressure during exercise was larger (P < 0.001) in older females (+11.6 ± 4.7 mmHg) compared with younger females (+4.1 ± 3.2 mmHg). MSNA burst frequency (BF) was decreased during cycling in both groups, but the magnitude of the decrease in MSNA BF was smaller (P = 0.004) in older females (-5.6 ± 1.8 bursts/min) than in younger females (-9.1 ± 2.5 bursts/min). The eCVP increased during exercise in both groups, and there was no difference in the changes in eCVP between the two groups (older, +0.80 ± 0.27 vs. younger, +1.02 ± 0.51 mmHg, P = 0.462). From these results, it is possible that the cardiopulmonary baroreflex-mediated inhibition of sympathetic vasomotor outflow, elicited by the muscle pump, may be attenuated with advancing age in females.NEW & NOTEWORTHY Aging does not affect the sympathoinhibitory effect of the cardiopulmonary baroreflex during low-intensity dynamic exercise in males; however, its impact on females remains unknown. The reduction in muscle sympathetic nerve activity burst frequency during low-intensity leg cycling was smaller in older females than in younger females, even with similar changes in estimated central venous pressure. In females, muscle pump-induced inhibition of sympathetic vasomotor outflow during leg cycling may be attenuated with advancing age.

  DOI PubMed

• Acute aerobic exercise enhances cerebrovascular shear-mediated dilation in young adults: the role of cerebral shear.

  Rintaro Sakamoto, Tatsuki Kamoda, Kohei Sato, Shigehiko Ogoh, Masaki Katayose, Toru Neki, Erika Iwamoto

  Journal of applied physiology (Bethesda, Md. : 1985)   136 ( 3 ) 535 - 548  2024.03  [International journal]

  Authorship：   Last author  , Corresponding author

  　View Summary

  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 PubMed

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Misc 【 display / non-display 】

Misc 【 display / non-display 】

• Effect of Leg Cycling with Different Degrees of Blood Flow Restriction on Brachial Flow-Mediated Dilation

  水野沙洸, 石田浩司, 齊藤満, 岩本えりか, 片山敬章

  デサントスポーツ科学   43  2022

  J-GLOBAL

• Effect of cigarette smoking on hypercapnia induced shear-mediated dilation in the internal carotid artery

  Kazuya Suzuki, Takuro Washio, Shingo Tsukamoto, Kazunori Kato, Erika Iwamoto, Shigehiko Ogoh

  FASEB JOURNAL ( WILEY )  33  2019.04

  Research paper, summary (international conference)  

  　View Summary

  0

• Respiratory Muscle Endurance And Cardiovascular Response To Hyperpnoea After Respiratory Muscle Training In Hypoxia

  Keisho Katayama, Erika Iwamoto, Toshiyuki Ohya, Kazushige Goto, Kenji Takao, Nobukazu Kasai, Daichi Sumi, Koji Ishida, Yasuhiro Suzuki

  MEDICINE AND SCIENCE IN SPORTS AND EXERCISE ( LIPPINCOTT WILLIAMS & WILKINS )  49 ( 5 ) 796 - 796  2017.05

  Research paper, summary (international conference)  

  DOI

• Combined Effect of Heating and Electrical Stimulation on Endothelial Vasodilator Function

  Erika Iwamoto, Shotaro Oiwa, Jiro Takami, Ryohei Nagaoka, Shota Ito, Toru Neki, Masaki Katayose

  FASEB JOURNAL ( FEDERATION AMER SOC EXP BIOL )  31  2017.04

  Research paper, summary (international conference)  

• Effects of acute electric stimulation on flow-mediated vasomotor function

  Shotaro Oiwa, Erika Iwamoto, Ryohei Nagaoka, Shota Ito, Jiro Takami, Toru Neki, Masaki Katayose

  Rigakuryoho Kagaku ( Society of Physical Therapy Science (Rigaku Ryoho Kagakugakkai) )  32 ( 2 ) 249 - 254  2017

  　View Summary

  [Purpose] The aim of the present study was to investigate the effects of acute electric stimulation on flow-mediated vasomotor function. [Subjects and Methods] Eight young healthy men participated in this study. Electrical stimulation was applied to the right forearm for 30 minutes. Before and after electrical stimulation, flow-mediated dilation (FMD) and low flow-mediated constriction (L-FMC) were measured at the right brachial artery. [Results] FMD and L-FMC tended to increase after electrical stimulation, but no significant differences were observed between pre- and post-stimulation. In contrast, FMD+L-FMC significantly increased after electrical stimulation compared to before stimulation. [Conclusion] These results suggest that acute electric stimulation affects flow-mediated vasoconstrictor and dilator functions. Further studies are needed to elucidate the effect of electrical parameter settings on the vascular function.

  DOI CiNii

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Awards 【 display / non-display 】

Awards 【 display / non-display 】

• 最優秀若手演題賞

  2022.11   日本血管血流学会  

  Winner： 坂本琳太郎 (指導教員 岩本えりか)

• John F. Perkins, Jr. Memorial Award for International Physiologists

  2019.06   American Physiological Society  

  Winner： IWAMOTO Erika

• International Early Career Physiologist Travel Award

  2018.04   American Physiological Society  

  Winner： IWAMOTO Erika

• 最優秀演題賞

  2015.11   日本血管血流学会  

  Winner： 岩本えりか

Research Projects 【 display / non-display 】

Research Projects 【 display / non-display 】

• 加齢に伴う血管収縮力増加に対抗し脳血流を維持するための新規メカニズムの解明

  基盤研究(B)

  Project Year :

  2025.04

  -

  2029.03

   

  岩本 えりか

• 糖尿病患者におけるレジスタンス運動中の眼圧上昇を防ぐ新規介入方策の開発

  挑戦的研究(萌芽)

  Project Year :

  2024.06

  -

  2027.03

   

  岩本 えりか, 片山 敬章, 小河 繁彦

• 心不全の治療経過に着目したサルコペニアの発症・進行因子の解明

  基盤研究(C)

  Project Year :

  2024.04

  -

  2027.03

   

  山田 悠, 角谷 尚哉, 岩本 えりか, 片寄 正樹

• Comparative Analysis of Cerebral and Peripheral Circulatory Function, Exercise Pressor Response, and Brain Anatomical Characteristics Between Japanese and Caucasian Americans

  Fund for the Promotion of Joint International Research (International Collaborative Research)

  Project Year :

  2023.09

  -

  2029.03

   

  小河 繁彦, 菅原 順, 岩本 えりか, 樽味 孝, 塚本 敏人

  　View Summary

  本国際共同研究では，欧米人と比較して日本人は，心血管疾患による死亡率が低いにもかかわらず，脳卒中による死亡率が非常に高い．この知見から．欧米人と異なり，心血管疾患発症リスク以外の脳循環生理要因の欧人との差異が，日本人の脳疾患発症リスクであるとの斬新な仮説を立てた．本国際共同研究では，日本及び米国で異なる人種の測定を行うことによりこの仮説を検証する．脳血管疾患発症リスクの人種間の差異について，環境・生活習慣要因を考慮した上で，運動効果や脳循環研究領域における検討は行われていない．本国際共同研究による仮説の検証は，日本人に最適な脳血管疾患予防法の確立の一助となる．人種間の体・脳循環機能の差異だけでなく，運動がこれら人種間の疾患発症やそのメカニズムの差異に及ぼす影響，さらに米国在住日本人の測定から環境・生活習慣の影響についても検討する．これらの研究結果から，心血管疾患及び脳疾患発症メカニズムの解明につながると考える．したがって，本研究の研究アプローチは，今までにない生理メカニズム解明のための新たな情報を提供する可能性を秘める． 本国際共同研究は２つの課題からなり，１年目から３年目にかけて，若年者を対象(日本人，白人米国人，米国在住日本人又は日系米国人，男女各10名)に脳疾患に関連する体・脳循環機能及び循環動態の測定を行い，脳疾患発症リスク要因の人種の差異を同定し，本交際共同研究の結果と先行研究の知見から脳疾患発症リスクの差異の原因を探る．本年度は研究期間の初年度であり，また採択から年度末まで期間が短いこともあり，初年度は，研究課題１の測定を日本と米国で行う為の実験の準備に終始した．アメリカの研究拠点となるテキサス大学とテキサス大学サウスウエスタンメディカルセンターのBrothers教授，Fadel教授，Fu教授と実験の方法，計画等の論議を行い，実験計画の確認を行った．

• Effect of the response of shear rate in the cerebral artery to exercise on cerebral endothelial function and cognitive function

  Grant-in-Aid for Scientific Research (B)

  Project Year :

  2022.04

  -

  2026.03

   

  小河 繁彦, 岩本 えりか, 橋本 健志

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Social Activities 【 display / non-display 】

Social Activities 【 display / non-display 】

• Review Editor, Frontiers in Physiology

  2022.06

  　

  　

• Reviewer, Journal of Applied Physiology

  2019.03

  　

  　

• Reviewer, Clinical Physiology and Functional Imaging

• Reviewer, Physiological Reports

• Reviewer, The Journal of Physiological Sciences

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