Affordable Access

Exercise training prevents the inflammatory response to hypoxia in cremaster venules.

Authors
  • Orth, Teresa A
  • Allen, Julie A
  • Wood, John G
  • Gonzalez, Norberto C
Type
Published Article
Journal
Journal of applied physiology (Bethesda, Md. : 1985)
Publication Date
Jun 01, 2005
Volume
98
Issue
6
Pages
2113–2118
Identifiers
PMID: 15705731
Source
Medline
License
Unknown

Abstract

Systemic hypoxia produces microvascular inflammation in several tissues, including skeletal muscle. Exercise training (ET) has been shown to reduce the inflammatory component of several diseases. Alternatively, ET could influence hypoxia-induced inflammation by improving tissue oxygenation or increasing mechanical antiadhesive forces at the leukocyte-endothelial interface. The effect of 5 wk of treadmill ET on hypoxia-induced microvascular inflammation was studied in the cremaster microcirculation of rats using intravital microscopy. In untrained rats, hypoxia (arterial Po(2) = 32.3 +/- 2.1 Torr) increased leukocyte-endothelial adherence from 2.3 +/- 0.4 to 10.2 +/- 0.3 leukocytes per 100 microm of venule (P < 0.05) and was accompanied by extravasation of FITC-labeled albumin after 4 h of hypoxia (extra-/intravascular fluorescence intensity ratio = 0.50 +/- 0.07). These responses were attenuated in ET (leukocyte adherence was 1.5 +/- 0.4 during normoxia and 1.8 +/- 0.7 leukocytes per 100 mum venule after 10 min of hypoxia; extra-/intravascular fluorescence intensity ratio = 0.11 +/- 0.02; P < 0.05 vs. untrained) despite similar reductions of arterial (32.4 +/- 1.8 Torr) and microvascular Po(2) (measured with an oxyphor-quenching method) in both groups. Shear rate decreased during hypoxia to similar extents in ET and untrained rats. In addition, circulating blood leukocyte count was similar in ET and untrained rats. The effects of ET on hypoxia-induced leukocyte-endothelial adherence remained up to 4 wk after discontinuing training. Thus ET attenuated hypoxia-induced inflammation despite similar effects of hypoxia on tissue Po(2), venular shear rate, and circulating leukocyte count.

Report this publication

Statistics

Seen <100 times