[Myocardial protection in hypothermia depends on the modulation of intracellular Ca2+ homeostasis].
The effect of a mild hypothermia (30 degrees C) on sarcoplasmic reticulum (SR) Ca2+ content and release has been evaluated in single cardiac cells loaded with the fluorescent indicator, indo-1. SR Ca2+ content, assessed by rapid caffeine application, is more pronounced at 30 than at 37 degrees C. However, hypothermia reduces the occurrence of spontaneous SR Ca2+ oscillations. In fact, following electrical stimulation, the time to onset of first SR Ca2+ oscillation was increased and their frequency reduced. Since spontaneous SR Ca2+ releases are implicated on the genesis of certain forms of ventricular arrhythmias, the protection provided by a mild hypothermia may be dependent on the modulation of intracellular Ca2+ homeostasis.
Gambassi
G
G
Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD.
Capogrossi
M C
MC
Mugelli
A
A
Carbonin
P
P
D000818:Animals; D002118:Calcium / Q000502:physiology*; D005453:Fluorescence; D005456:Fluorescent Dyes; D006321:Heart / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D007036:Hypothermia, Induced; D066298:In Vitro Techniques; D007211:Indoles; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000502:physiology
D005456:Fluorescent Dyes; D007211:Indoles; C048960:indo-1; D002118:Calcium
La protezione miocardica in ipotermia dipende dalla modulazione della omeostasi intracellulare del Ca2+.