Post-rest contractions of amphibian cardiac muscle
Braz. j. med. biol. res
; 24(8): 843-6, 1991. ilus
Article
in En
| LILACS
| ID: lil-102075
Responsible library:
BR1.1
ABSTRACT
Post-rest potentiated contractions have been reported to be more dependent on Ca2+ stored in intracellular sites than on transmembrana Ca2+ influx. The phenomenon was examined using toad ventricular strips contracting isometrically and superfused with Ringer solution. Toad ventricular strips did not present post-rest potentiation, a fact that may be explained be the reduced volume of the sarcoplasmic reticulum in the amphibian myocardium. Potentiated post-res contractins were obtained after calcium influx blockade with 10 µM verapamil or 2mM Mn2+ and the slow reduction of extracellular Ca2+ concentration obtained by slowly exchanging the bath fluid was accompanied by a progressive decrease of both steady-state and post-rest contractions. These data suggestion of the dependende of post-rest potentiation on activator calcium liberated from intracellular stores
Search on Google
Index:
LILACS
Main subject:
Calcium
/
Extracellular Space
/
Myocardial Contraction
Limits:
Animals
Language:
En
Journal:
Braz. j. med. biol. res
Journal subject:
BIOLOGIA
/
MEDICINA
Year:
1991
Type:
Article
/
Congress and conference
/
Project document