Alpha-stat calibration of indo-1 fluorescence and measurement of intracellular free calcium in rat ventricular cells at different temperatures

作者：Wang SQ^*; Zhou ZQ

来源：Life Sciences, 1999, 65(9): 871-877.

DOI：10.1016/S0024-3205(99)00317-3

• alpha-stat pH management
• intracellular free calcium
• fluorescent Ca2+ probe
• temperature
• cardiac myocute

To explore how to manage pH when calibrating Ca2+ probes at different temperatures, the dissociation constant (K-d) of indo-1 was determined both in pH-stat (pH is fixed despite the temperature) and in alpha-stat (pH changes with temperature as in cells). The results showed that the K-d was much more sensitive to temperature in pH-stat than in alpha-stat, demonstrating that alpha-stat calibration should be preferred when using a Ca2+ probe to measure intracellular free calcium ([Ca2+](i)) at different temperatures. Based on the calibration in situ and in alpha-stat, we showed a striking increase of [Ca2+](i) from 141+/-8 nM at 30 degrees C to 218+/-22 nM at 10 degrees C in indo-1 loaded rat ventricular cells, which supports that intracellular calcium overload takes place in cardiac myocytes of non-hibernating mammals during hypothermia.

• 出版日期1999-7-23
• 单位北京大学