Quantification of intracellular free sodium ions by using a new fluorescent indicator, sodium-binding benzofuran isophthalate in guinea pig myocytes.
Isolated guinea pig myocytes were loaded with the Na(+)-sensitive fluorescent probe, sodium-binding benzofuran isophthalate (SBFI). The 340/380 nm fluorescence ratios were measured with fluorescence microscopy. The distribution of intracellular Na+ concentration ([Na+]i) was homogenous, and the mean resting [Na+]i was 8.4 +/- 0.5 mM. There was a significant relationship (r = 0.66, p less than 0.001) between elevation of [Na+]i and shortening of longitudinal length of the cells, during the perfusion of 100 microM strophanthidin. It is concluded that this method is suitable for measuring [Na+]i in isolated myocytes.
Satoh
H
H
Third Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
Hayashi
H
H
Noda
N
N
Terada
H
H
Kobayashi
A
A
Yamashita
Y
Y
Kawai
T
T
Hirano
M
M
Yamazaki
N
N
D000818:Animals; D001572:Benzofurans / Q000737:chemistry*; D003593:Cytoplasm / Q000737:chemistry*; D004988:Ethers, Cyclic / Q000737:chemistry*; D005456:Fluorescent Dyes; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D009132:Muscles / Q000737:chemistry; D012964:Sodium / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013327:Strophanthidin / Q000494:pharmacology
D001572:Benzofurans; D004988:Ethers, Cyclic; D005456:Fluorescent Dyes; C061664:sodium-binding benzofuran phthalate; D013327:Strophanthidin; D012964:Sodium