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 < 0.01). After the 40 min perfusion of 1 microM hexamethylene amiloride (HMA), [Na+]i decreased significantly in both groups. However, there was no difference in [Na+]i between the two groups after the perfusion of HMA. It was suggested that the lower [Na+]i in diabetic myocytes could be due to the decreased activity of Na+/H+ exchange system.
Katoh
H
H
Third Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
Noda
N
N
Hayashi
H
H
Satoh
H
H
Terada
H
H
Ohno
R
R
Yamazaki
N
N
D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers / Q000187:drug effects; D013311:Streptozocin
D017923:Sodium-Hydrogen Exchangers; C057360:5-(N,N-hexamethylene)amiloride; D013311:Streptozocin; D000584:Amiloride; D012964:Sodium