Microscopic detection of thermogenesis in a single HeLa cell
Madoka Suzuki 1, Vadim Tseeb 1, Kotaro Oyama 1 and Shin'ichi Ishiwata 1*
1 Waseda University
* To whom correspondence should be addressed. E-mail: ishiwata{at}waseda.jp.
Submitted on October 2, 2006
Revised on November 7, 2006
Accepted on 18 January 2007
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Abstract |
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We report here the technique for detection and measurement of the temperature changes in single cells using a recently devised microthermometer (a glass micropipette filled with the thermosensitive fluorescent dye Europium (III) thenoyltrifluoroacetonate trihydrate). We found that the heat production in a single HeLa cell occurred with some time delay after the ionomycin-induced Ca2+ influx from the extracellular space. The time delay inversely depended on extracellular [Ca2+], and the increase in temperature was suppressed when Ca2+-ATPases were blocked by thapsigargin. These observations strongly suggest that the enzymatic activity of Ca2+-ATPases in endoplasmic reticulum leads to the heat production. The present study has therefore paved the way for studying the thermogenesis at the single-cell level.
Key Words:
Ca-ATPase, Europium-TTA, Imaging of temperature in microvolume, Ionomycin, Microthermometer, Thapsigargin
