A method to estimate mitochondrial Ca2+ uptake in intact cardiac myocytes
Braz. j. med. biol. res
;
29(12): 1699-1707, Dec. 1996. ilus
Article
in English
| LILACS
| ID: lil-188457
ABSTRACT
In the present paper we describe a method to estimate mitochondrial Ca2+ uptake during the declining phase of Ca2+ transients (cell relaxation) in intact isolated myocardial cells. This method is based on inhibition of sarcoplasmic reticulum (SR) Ca2+ accumulation by caffeine, blockade of Ca2+ transport via sarcolemmal Ca2+ -ATPase by treatment with carboxyeosin and inhibition of sarcolemmal Na+/Ca+ exchange by removal of extracellular Na+ and Ca2+. Ca2+ transients were evoked in rabbit ventricular myocytes by quick and sustained caffeine application (10 mM) after a 5-min period of electrical stimulation to load the SR with Ca2+. Mitochondrial Ca2+ transport was estimated using a model described by Sipido and Wier (Journal of Physiology (1991), 435: 605-630), which was originally proposed to describe Ca2+ fluxes during excitation-contraction coupling in cardiac cells. Our results indicate that, in intact rabbit myocytes, the Ca2+ flux due to net mitochondrial CA2+ uptake may attain a value close to 1 muM/sec.
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Index:
LILACS (Americas)
Main subject:
In Vitro Techniques
/
Calcium
/
Ion Transport
/
Mitochondria, Heart
/
Myocardial Contraction
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
1996
Type:
Article
/
Project document
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