THE EFFECTS OF PH AND TEMPERATURE ON FLUORESCENT CALCIUM INDICATORS AS DETERMINED WITH CHELEX-100 AND EDTA BUFFER SYSTEMS

被引:155
作者
LATTANZIO, FA
机构
[1] Department of Pharmacology, Eastern Virginia Medical School, Norfolk, VA 23501
关键词
D O I
10.1016/0006-291X(90)91362-V
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A novel method of determining the apparent dissociation constants of fluorescent calcium indicators is described which utilizes Chelex-100 ion exchange resin and 45Ca. The affinity for calcium of indicators fluo-3, fura-2 and indo-1 measured at either 22° or 37°C decreases as pH is decreased from 7.4 to 5.5. These measurements agree with determinations made using EDTA-calcium buffers. The 1:1 calcium:indicator complex is maintained under all conditions. The necessity to correct dissociation constants during intracellular acidification to properly interpret fluorescence measurements is illustrated by indo-1 measurements in the ischemic rat heart. © 1990.
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页码:102 / 108
页数:7
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