Free-radical production triggered by hyperthermia contributes to heat stress-induced cardioprotection in isolated rat hearts. - Archive ouverte HAL Access content directly
Journal Articles British Journal of Pharmacology Year : 2002

Free-radical production triggered by hyperthermia contributes to heat stress-induced cardioprotection in isolated rat hearts.

(1) , (1) , (2) , (1) , (1) , (1)
1
2

Abstract

1. Heat stress (HS) is known to protect the myocardium against ischaemic damage. It has been reported that reactive oxygen species (ROS) are abundantly produced during this stress. Since mechanisms triggering the HS-induced cardioprotection remain unknown, we investigated the role of ROS in the genesis of this protective phenomenon. 2. Rats were divided into four groups (n=8 in each group), subjected to either hyperthermia (42 degrees C internal temperature for 15 min) or sham anaesthesia and treated or not with N-2-mercaptopropionyl glycine (MPG), a synthetic antioxidant, 10 min before HS. Twenty-four hours later, their hearts were isolated, retrogradely perfused, and subjected to a 30-min occlusion of the left coronary artery followed by 120 min of reperfusion. Myocardial Hsp 27 and 70 expression was assessed by Western blot analysis (n=4). Cardiac activities of antioxidant enzymes (superoxide dismutase and glutathione peroxidase) were also examined (n=4). 3. Infarct-to-risk zone ratio was significantly reduced in HS (17+/-1.3%) compared to Sham (34.3+/-1.7%) hearts. This effect was abolished by MPG pretreatment (40.6+/-1.9% in HS+MPG vs. 39.8+/-2.5% in Sham+MPG hearts). This cardioprotection was associated with an enhanced Hsp 27 and 70 expression, which was not modified by MPG pretreatment. Antioxidant enzyme activities was not modified by heat stress or MPG pretreatment. 4. Free radical production following hyperthermia appears to play a role in the heat stress induced cardioprotection, independently of Hsp levels. Antioxidant enzyme activities do not seem to be implicated in this cardioprotective mechanism.
Fichier principal
Vignette du fichier
MPG.pdf (266.58 Ko) Télécharger le fichier
Loading...

Dates and versions

inserm-00266209 , version 1 (21-03-2008)

Identifiers

Cite

Claire Arnaud, Marie Joyeux, Catherine Garrel, Diane Godin-Ribuot, Pierre Demenge, et al.. Free-radical production triggered by hyperthermia contributes to heat stress-induced cardioprotection in isolated rat hearts.. British Journal of Pharmacology, 2002, 135 (7), pp.1776-82. ⟨10.1038/sj.bjp.0704619⟩. ⟨inserm-00266209⟩

Collections

INSERM UGA
219 View
243 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More