Ten-day endurance training attenuates the hyperosmotic suppression of cutaneous vasodilation during exercise but not sweating

Takashi Ichinose, Kazunobu Okazaki, Shizue Masuki, Hiroyuki Mitono, Mian Chen, Hiroshi Endoh, Hiroshi Nose

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

It is well known that hyperosmolality suppresses thermoregulatory responses and that plasma osmolality (Posmol) increases with exercise intensity. We examined whether the decreased esophageal temperature thresholds for cutaneous vasodilation (THFVC) and sweating (THSR) after 10-day endurance training (ET) are caused by either attenuated increase in Posmol at a given exercise intensity or blunted sensitivity of hyperosmotic suppression. Nine young male volunteers exercised on a cycle ergometer at 60% peak oxygen consumption rate (V̇O2 peak) for 1 h/day for 10 days at 30°C. Before and after ET, thermoregulatory responses were measured during 20-min exercise at pretraining 70% V̇O2 peak in the same environment as during ET under isoosmotic or hyperosmotic conditions. Hyperosmolality by ∼4% mosmol/kgH2O was attained by acute hypertonic saline infusion. After ET, V̇O2 peak and blood volume (BV) both increased by ∼4% (P < 0.05), followed by a decrease in THFVC (P < 0.05) but not by that in THSR. Although there was no significant decrease in Posmol at the thresholds after ET, the sensitivity of increase in THFVC at a given increase in Posmol [ΔTHFVC/ ΔPosmol, °C · (mosmol/kgH2O)-1], determined by hypertonic infusion, was reduced to 0.021 ± 0.005 from 0.039 ± 0.004 before ET (P < 0.05). The individual reductions in ΔTHFVC/ ΔPosmol after ET were highly correlated with their increases in BV around THFVC (r = -0.89, P < 0.005). In contrast, there was no alteration in the sensitivity of the hyperosmotic suppression of sweating after ET. Thus the downward shift of THFVC after ET was partially explained by the blunted sensitivity to hyperosmolality, which occurred in proportion to the increase in BV.

Original languageEnglish
Pages (from-to)237-243
Number of pages7
JournalJournal of Applied Physiology
Volume99
Issue number1
DOIs
Publication statusPublished - 2005 Jul
Externally publishedYes

Fingerprint

Sweating
Vasodilation
Osmolar Concentration
Exercise
Skin
Blood Volume
Oxygen Consumption
Volunteers
Temperature

Keywords

  • Esophageal temperature threshold
  • Plasma volume

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Ten-day endurance training attenuates the hyperosmotic suppression of cutaneous vasodilation during exercise but not sweating. / Ichinose, Takashi; Okazaki, Kazunobu; Masuki, Shizue; Mitono, Hiroyuki; Chen, Mian; Endoh, Hiroshi; Nose, Hiroshi.

In: Journal of Applied Physiology, Vol. 99, No. 1, 07.2005, p. 237-243.

Research output: Contribution to journalArticle

Ichinose, Takashi ; Okazaki, Kazunobu ; Masuki, Shizue ; Mitono, Hiroyuki ; Chen, Mian ; Endoh, Hiroshi ; Nose, Hiroshi. / Ten-day endurance training attenuates the hyperosmotic suppression of cutaneous vasodilation during exercise but not sweating. In: Journal of Applied Physiology. 2005 ; Vol. 99, No. 1. pp. 237-243.
@article{992cb93b53e344219240664db147838f,
title = "Ten-day endurance training attenuates the hyperosmotic suppression of cutaneous vasodilation during exercise but not sweating",
abstract = "It is well known that hyperosmolality suppresses thermoregulatory responses and that plasma osmolality (Posmol) increases with exercise intensity. We examined whether the decreased esophageal temperature thresholds for cutaneous vasodilation (THFVC) and sweating (THSR) after 10-day endurance training (ET) are caused by either attenuated increase in Posmol at a given exercise intensity or blunted sensitivity of hyperosmotic suppression. Nine young male volunteers exercised on a cycle ergometer at 60{\%} peak oxygen consumption rate (V̇O2 peak) for 1 h/day for 10 days at 30°C. Before and after ET, thermoregulatory responses were measured during 20-min exercise at pretraining 70{\%} V̇O2 peak in the same environment as during ET under isoosmotic or hyperosmotic conditions. Hyperosmolality by ∼4{\%} mosmol/kgH2O was attained by acute hypertonic saline infusion. After ET, V̇O2 peak and blood volume (BV) both increased by ∼4{\%} (P < 0.05), followed by a decrease in THFVC (P < 0.05) but not by that in THSR. Although there was no significant decrease in Posmol at the thresholds after ET, the sensitivity of increase in THFVC at a given increase in Posmol [ΔTHFVC/ ΔPosmol, °C · (mosmol/kgH2O)-1], determined by hypertonic infusion, was reduced to 0.021 ± 0.005 from 0.039 ± 0.004 before ET (P < 0.05). The individual reductions in ΔTHFVC/ ΔPosmol after ET were highly correlated with their increases in BV around THFVC (r = -0.89, P < 0.005). In contrast, there was no alteration in the sensitivity of the hyperosmotic suppression of sweating after ET. Thus the downward shift of THFVC after ET was partially explained by the blunted sensitivity to hyperosmolality, which occurred in proportion to the increase in BV.",
keywords = "Esophageal temperature threshold, Plasma volume",
author = "Takashi Ichinose and Kazunobu Okazaki and Shizue Masuki and Hiroyuki Mitono and Mian Chen and Hiroshi Endoh and Hiroshi Nose",
year = "2005",
month = "7",
doi = "10.1152/japplphysiol.00813.2004",
language = "English",
volume = "99",
pages = "237--243",
journal = "Journal of Applied Physiology Respiratory Environmental and Exercise Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Ten-day endurance training attenuates the hyperosmotic suppression of cutaneous vasodilation during exercise but not sweating

AU - Ichinose, Takashi

AU - Okazaki, Kazunobu

AU - Masuki, Shizue

AU - Mitono, Hiroyuki

AU - Chen, Mian

AU - Endoh, Hiroshi

AU - Nose, Hiroshi

PY - 2005/7

Y1 - 2005/7

N2 - It is well known that hyperosmolality suppresses thermoregulatory responses and that plasma osmolality (Posmol) increases with exercise intensity. We examined whether the decreased esophageal temperature thresholds for cutaneous vasodilation (THFVC) and sweating (THSR) after 10-day endurance training (ET) are caused by either attenuated increase in Posmol at a given exercise intensity or blunted sensitivity of hyperosmotic suppression. Nine young male volunteers exercised on a cycle ergometer at 60% peak oxygen consumption rate (V̇O2 peak) for 1 h/day for 10 days at 30°C. Before and after ET, thermoregulatory responses were measured during 20-min exercise at pretraining 70% V̇O2 peak in the same environment as during ET under isoosmotic or hyperosmotic conditions. Hyperosmolality by ∼4% mosmol/kgH2O was attained by acute hypertonic saline infusion. After ET, V̇O2 peak and blood volume (BV) both increased by ∼4% (P < 0.05), followed by a decrease in THFVC (P < 0.05) but not by that in THSR. Although there was no significant decrease in Posmol at the thresholds after ET, the sensitivity of increase in THFVC at a given increase in Posmol [ΔTHFVC/ ΔPosmol, °C · (mosmol/kgH2O)-1], determined by hypertonic infusion, was reduced to 0.021 ± 0.005 from 0.039 ± 0.004 before ET (P < 0.05). The individual reductions in ΔTHFVC/ ΔPosmol after ET were highly correlated with their increases in BV around THFVC (r = -0.89, P < 0.005). In contrast, there was no alteration in the sensitivity of the hyperosmotic suppression of sweating after ET. Thus the downward shift of THFVC after ET was partially explained by the blunted sensitivity to hyperosmolality, which occurred in proportion to the increase in BV.

AB - It is well known that hyperosmolality suppresses thermoregulatory responses and that plasma osmolality (Posmol) increases with exercise intensity. We examined whether the decreased esophageal temperature thresholds for cutaneous vasodilation (THFVC) and sweating (THSR) after 10-day endurance training (ET) are caused by either attenuated increase in Posmol at a given exercise intensity or blunted sensitivity of hyperosmotic suppression. Nine young male volunteers exercised on a cycle ergometer at 60% peak oxygen consumption rate (V̇O2 peak) for 1 h/day for 10 days at 30°C. Before and after ET, thermoregulatory responses were measured during 20-min exercise at pretraining 70% V̇O2 peak in the same environment as during ET under isoosmotic or hyperosmotic conditions. Hyperosmolality by ∼4% mosmol/kgH2O was attained by acute hypertonic saline infusion. After ET, V̇O2 peak and blood volume (BV) both increased by ∼4% (P < 0.05), followed by a decrease in THFVC (P < 0.05) but not by that in THSR. Although there was no significant decrease in Posmol at the thresholds after ET, the sensitivity of increase in THFVC at a given increase in Posmol [ΔTHFVC/ ΔPosmol, °C · (mosmol/kgH2O)-1], determined by hypertonic infusion, was reduced to 0.021 ± 0.005 from 0.039 ± 0.004 before ET (P < 0.05). The individual reductions in ΔTHFVC/ ΔPosmol after ET were highly correlated with their increases in BV around THFVC (r = -0.89, P < 0.005). In contrast, there was no alteration in the sensitivity of the hyperosmotic suppression of sweating after ET. Thus the downward shift of THFVC after ET was partially explained by the blunted sensitivity to hyperosmolality, which occurred in proportion to the increase in BV.

KW - Esophageal temperature threshold

KW - Plasma volume

UR - http://www.scopus.com/inward/record.url?scp=21644466388&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=21644466388&partnerID=8YFLogxK

U2 - 10.1152/japplphysiol.00813.2004

DO - 10.1152/japplphysiol.00813.2004

M3 - Article

C2 - 15761088

AN - SCOPUS:21644466388

VL - 99

SP - 237

EP - 243

JO - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

JF - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

SN - 8750-7587

IS - 1

ER -