Intracellular Sodium Concentration in Diabetic Rat Ventricular Myocytes.

Intracellular sodium concentration in diabetic rat ventricular myocytes.

We measured intracellular NA+ concentration ([Na+]i) of diabetic rat ventricular myocytes using sodium-binding benzofuran isophthalate (SBFI). We used diabetic rats at 8 weeks after the injection of streptozotocin (45 mg/kg i.v.). The level of [Na+]i during the control perfusion was significantly lower in diabetic myocytes than that in normal myocytes (9.2 +/- 0.4 mM v.s. 12.0 +/- 0.3 mM, p < 0...

Stimulation of muscarinic receptors raises free intracellular Ca2+ concentration in rat ventricular myocytes.

The effect of carbachol on free intracellular calcium concentration, ([Ca2+]i) and on intracellular hydrogen concentration (pHi) was determined from fluorescence signals obtained from rat ventricular myocytes. Application of carbachol (300 mumol/l) to quin2-loaded myocytes bathed in 2 mmol/l Ca2+-containing solution caused [Ca2+]i to increase within 7-10 minutes from 182 +/- 9 to 212 +/- 11 nmo...

Cytosolic Ca2+ concentration decreases in diabetic rat myocytes.

Diabetes mellitus has been shown to be associated with heart failure of unknown origin, which is termed ‘diabetic w x w x cardiomyopathy’ 1 . Regan et al. 2 have shown that the small vessel lesions in diabetes mellitus have little or no relation to diabetic cardiomyopathy, suggesting that the contractile function of the diabetic cardiomyopathy was primarily defective. Although many studies have...

Tamoxifen inhibits sodium and potassium currents in rat ventricular myocytes

Intracellular sodium determines frequency-dependent alterations in contractility in hypertrophied feline ventricular myocytes.

Hypertrophy and failure (H/F) in humans and large mammals are characterized by a change from a positive developed force-frequency relationship (+FFR) in normal myocardium to a flattened or negative developed force-frequency relationship (-FFR) in disease. Altered Ca(2+) homeostasis underlies this process, but the role of intracellular Na(+) concentration ([Na(+)](i)) in H/F and frequency-depend...