Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow

Ilkka Heinonen, R. Matthew Brothers, Jukka Kemppainen, Juhani Knuuti, Kari K. Kalliokoski, Craig G. Crandall

Research output: Contribution to journalArticle

71 Citations (Scopus)

Abstract

For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positronemission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g -1·min -1 (P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g -1·min -1 (P < 0.01). While whole body heat stress increased intestinal temperature by ∼1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml · 100 g -1 · min -1; heat stress: 1.7 ± 0.3 ml·100 g -1·min -1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g -1·min -1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.

Original languageEnglish (US)
Pages (from-to)818-824
Number of pages7
JournalJournal of Applied Physiology
Volume111
Issue number3
DOIs
StatePublished - Sep 2011

Fingerprint

Heating
Skeletal Muscle
Hot Temperature
Muscles
Skin
Temperature
Water
Leg
Tomography

Keywords

  • Bone blood flow
  • Heat stress
  • Positron-emission tomography
  • Skin blood flow

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow. / Heinonen, Ilkka; Brothers, R. Matthew; Kemppainen, Jukka; Knuuti, Juhani; Kalliokoski, Kari K.; Crandall, Craig G.

In: Journal of Applied Physiology, Vol. 111, No. 3, 09.2011, p. 818-824.

Research output: Contribution to journalArticle

Heinonen, Ilkka ; Brothers, R. Matthew ; Kemppainen, Jukka ; Knuuti, Juhani ; Kalliokoski, Kari K. ; Crandall, Craig G. / Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow. In: Journal of Applied Physiology. 2011 ; Vol. 111, No. 3. pp. 818-824.
@article{351474fa29d749208bdb979004494c51,
title = "Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow",
abstract = "For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positronemission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g -1·min -1 (P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g -1·min -1 (P < 0.01). While whole body heat stress increased intestinal temperature by ∼1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml · 100 g -1 · min -1; heat stress: 1.7 ± 0.3 ml·100 g -1·min -1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g -1·min -1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.",
keywords = "Bone blood flow, Heat stress, Positron-emission tomography, Skin blood flow",
author = "Ilkka Heinonen and Brothers, {R. Matthew} and Jukka Kemppainen and Juhani Knuuti and Kalliokoski, {Kari K.} and Crandall, {Craig G.}",
year = "2011",
month = "9",
doi = "10.1152/japplphysiol.00269.2011",
language = "English (US)",
volume = "111",
pages = "818--824",
journal = "Journal of Applied Physiology",
issn = "0161-7567",
publisher = "American Physiological Society",
number = "3",

}

TY - JOUR

T1 - Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow

AU - Heinonen, Ilkka

AU - Brothers, R. Matthew

AU - Kemppainen, Jukka

AU - Knuuti, Juhani

AU - Kalliokoski, Kari K.

AU - Crandall, Craig G.

PY - 2011/9

Y1 - 2011/9

N2 - For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positronemission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g -1·min -1 (P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g -1·min -1 (P < 0.01). While whole body heat stress increased intestinal temperature by ∼1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml · 100 g -1 · min -1; heat stress: 1.7 ± 0.3 ml·100 g -1·min -1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g -1·min -1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.

AB - For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positronemission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g -1·min -1 (P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g -1·min -1 (P < 0.01). While whole body heat stress increased intestinal temperature by ∼1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml · 100 g -1 · min -1; heat stress: 1.7 ± 0.3 ml·100 g -1·min -1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g -1·min -1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.

KW - Bone blood flow

KW - Heat stress

KW - Positron-emission tomography

KW - Skin blood flow

UR - http://www.scopus.com/inward/record.url?scp=80052988207&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80052988207&partnerID=8YFLogxK

U2 - 10.1152/japplphysiol.00269.2011

DO - 10.1152/japplphysiol.00269.2011

M3 - Article

VL - 111

SP - 818

EP - 824

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 0161-7567

IS - 3

ER -