Quantitative analysis of spontaneous mitochondrial depolarizations

被引:109
作者
O'Reilly, CM
Fogarty, KE
Drummond, RM
Tuft, RA
Walsh, JV
机构
[1] Univ Massachusetts, Sch Med, Dept Physiol, Worcester, MA 01655 USA
[2] Univ Massachusetts, Sch Med, Biomed Imaging Grp, Worcester, MA 01655 USA
关键词
D O I
10.1016/S0006-3495(03)74754-7
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
Spontaneous transient depolarizations in mitochondrial membrane potential (DeltaPsi(m)), mitochondrial flickers, have been observed in isolated mitochondria and intact cells using the fluorescent probe, tetramethylrhodamine ethyl ester ( TMRE). In theory, the ratio of [TMRE] in cytosol and mitochondrion allows DeltaPsi(m) to be calculated with the Nernst equation, but this has proven difficult in practice due to fluorescence quenching and binding of dye to mitochondrial membranes. We developed a new method to determine the amplitude of flickers in terms of millivolts of depolarization. TMRE fluorescence was monitored using high-speed, high-sensitivity three-dimensional imaging to track individual mitochondria in freshly dissociated smooth muscle cells. Resting mitochondrial fluorescence, an exponential function of resting DeltaPsi(m), varied among mitochondria and was approximately normally distributed. Spontaneous changes in mitochondrial fluorescence, indicating depolarizations and repolarizations in DeltaPsi(m), were observed. The depolarizations were reversible and did not result in permanent depolarization of the mitochondria. The magnitude of the flickers ranged from <10 mV to >100 mV with a mean of 17.6 +/- 1.0 mV (n = 360) and a distribution skewed to smaller values. Nearly all mitochondria flickered, and they did so independently of one another, indicating that mitochondria function as independent units in the myocytes employed here.
引用
收藏
页码:3350 / 3357
页数:8
相关论文
共 20 条
[1]   Spontaneous changes in mitochondrial membrane potential in cultured neurons [J].
Buckman, JF ;
Reynolds, IJ .
JOURNAL OF NEUROSCIENCE, 2001, 21 (14) :5054-5065
[2]   SUPERRESOLUTION 3-DIMENSIONAL IMAGES OF FLUORESCENCE IN CELLS WITH MINIMAL LIGHT EXPOSURE [J].
CARRINGTON, WA ;
LYNCH, RM ;
MOORE, EDW ;
ISENBERG, G ;
FOGARTY, KE ;
FREDRIC, FS .
SCIENCE, 1995, 268 (5216) :1483-1487
[3]  
CARRINGTON WA, 1990, NONINVASIVE TECHNIQU, P53
[4]   Mitochondria are morphologically and functionally heterogeneous within cells [J].
Collins, TJ ;
Berridge, MJ ;
Lipp, P ;
Bootman, MD .
EMBO JOURNAL, 2002, 21 (07) :1616-1627
[5]   Electrical coupling and plasticity of the mitochondrial network [J].
De Giorgi, F ;
Lartigue, L ;
Ichas, F .
CELL CALCIUM, 2000, 28 (5-6) :365-370
[6]   Homogeneous longitudinal profiles and synchronous fluctuations of mitochondrial transmembrane potential [J].
Diaz, G ;
Falchi, AM ;
Gremo, F ;
Isola, R ;
Diana, A .
FEBS LETTERS, 2000, 475 (03) :218-224
[7]   Mitochondrial Ca2+ homeostasis during Ca2+ influx and Ca2+ release in gastric myocytes from Bufo marinus [J].
Drummond, RM ;
Mix, TCH ;
Tuft, RA ;
Walsh, JV ;
Fay, FS .
JOURNAL OF PHYSIOLOGY-LONDON, 2000, 522 (03) :375-390
[8]   Transient mitochondrial depolarizations reflect focal sarcoplasmic reticular calcium release in single rat cardiomyocytes [J].
Duchen, MR ;
Leyssens, A ;
Crompton, M .
JOURNAL OF CELL BIOLOGY, 1998, 142 (04) :975-988
[9]   Contributions of mitochondria to animal physiology: from homeostatic sensor to calcium signalling and cell death [J].
Duchen, MR .
JOURNAL OF PHYSIOLOGY-LONDON, 1999, 516 (01) :1-17
[10]   Visualization of cyclosporin A and Ca2+-sensitive cyclical mitochondrial depolarizations in cell culture [J].
Fall, CP ;
Bennett, JP .
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 1999, 1410 (01) :77-84