Calcium transients in aequorin-injected frog cardiac muscle.
The Ca2+ -sensitive bioluminescent protein aequorin was microinjected into cells of frog atrial trabeculae to study intracellular calcium transients associated with excitation-contraction coupling. The amplitude of the aequorin signal increased with extracellular Ca2+ concentration and stimulus frequency, but decreased with stretch. Isoprenaline and acetylstrophanthidin both increased the amplitude, but had strikingly different effects on the time course of the signal.
D000200:Action Potentials; D000331:Aequorin; D000818:Animals; D001001:Anura; D002118:Calcium / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D006339:Heart Rate; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D011894:Rana pipiens; D013327:Strophanthidin / Q000031:analogs & derivatives / Q000494:pharmacology
D000331:Aequorin; D013327:Strophanthidin; D007545:Isoproterenol; D002118:Calcium