Detection of Ca2+‐transients elicited by flash photolysis of DM‐nitrophen with a fast calcium indicator

FEBS Letters

Escobar, Ariel L.¹  Vergara, Julio L.¹  Cifuentes, Fredy¹ 

[1] Department of Physiology, UCLA School of Medicine, Los Angeles, CA 90024, USA

关键词: Flash photolysis;    Ca2+ dyes;    Kinetic rate constant;    Ca2+ transient;   

DOI  :  10.1016/0014-5793(95)00425-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A confocal spot detection optical setup was used to record fluorescence signals in response to calcium pulses, elicited by flash photolysis of DM-nitrophen, with the calcium indicators CaOrange-5N and Fluo-3. Our results yield the following conclusions: [Ca²⁺] changes are almost perfect spikes at pCa 9 and broader transients followed by a step at pCa 7. The [Ca²⁺] spikes were used to measure the dissociation rate constant of the Ca²⁺ dyes. Experiments at pCa 7 were used to verify the kinetic rate constants of the dyes and to obtain those of DM-nitrophen. The association rate constant of this compound was found to be more than one order of magnitude faster than that suggested previously. CaOrange-5N was able to track changes in [Ca²⁺] more accurately than Fluo-3. This latter dye introduced severe distortions which preclude a quantitative deconvolution of the fluorescence transients into changes in the free [Ca²⁺].

【 授权许可】

Unknown