title: [Monitoring calcium in outer hair cells with confocal microscopy and fluorescence ratios of fluo-3 and fura-red].
abstract: Calcium distribution and mobilization during mechanical stimulation in outer hair cells of the guinea pig were monitored using laser scanning confocal microscopy and co-loaded fluo-3 and fura-red fluorescent probes. Spatial calcium gradients were revealed among various subcellular areas. The ratios of the fluorescence intensity of fluo-3 and fura-red were 1.71 +/- 0.85, 1.61 +/- 0.75, 1.47 +/- 0.65 and 1.39 +/- 0.66 for the cytoplasm, the cytoplasmic membrane, the cuticular plate and the nucleus respectively, indicating that free calcium ion concentrations are the highest in the cytoplasm and the lowest in the nucleus. While the calcium concentration remained relatively constant under resting conditions, it increased during mechanical stimulation. The results show that confocal ratio imaging of fluo-3 and fura-red enables us to determine more accurately the subcellular calcium distribution and that the calcium ions make a contribution to the mechanic-electrical transduction in hair cells.
authors.affiliation: Institute of Otolaryngology and Medical Experiment and Analyze Center, Chinese PLA General Hospital, Beijing 100853.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Su
authors.forename: N
authors.initials: N
authors.lastname: Li
authors.forename: Y R
authors.initials: YR
authors.lastname: Sun
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: I M
authors.initials: IM
authors.lastname: Wang
authors.forename: S C
authors.initials: SC
authors.lastname: Jiang
mesh_terms: D000814:Aniline Compounds; D000818:Animals; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005456:Fluorescent Dyes; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000378:metabolism*; D007093:Imidazoles; D018613:Microscopy, Confocal; D014966:Xanthenes
chemical_list: D000814:Aniline Compounds; D001572:Benzofurans; D005456:Fluorescent Dyes; D007093:Imidazoles; D014966:Xanthenes; C082877:fura red; C059715:Fluo-3; D002118:Calcium