A comparison of cytosolic free Ca2+ in resting feline and rat ventricular myocytes.
The Ca2+-sensitive dye quin-2 was used to measure the cytosolic free Ca2+ (Cai2+) in suspensions of ventricular myocytes isolated from cat and rat ventricles. Following an isolation procedure that was similar for both species, the cells were loaded with quin-2 AM (25 microM) for 30 min at 37 degrees C. After two washes to remove extracellular dye, the cells were resuspended for fluorescence measurements. Extracellular Ca2+ was 2.0 mM. Resting Cai2+ in the rat (121 +/- 11 nM) was found to be significantly higher than in the cat (57 +/- 4 nM). These results are discussed in terms of known differences in excitation-contraction coupling between these two species.
D000634:Aminoquinolines; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002415:Cats; D003600:Cytosol / Q000378:metabolism*; D005456:Fluorescent Dyes; D006352:Heart Ventricles; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D013050:Spectrometry, Fluorescence
D000634:Aminoquinolines; D005456:Fluorescent Dyes; C035739:Quin2; D002118:Calcium