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Updated: Aug 18, 2026

Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging
Published on: June 20, 2016
Effects of thapsigargin on stimulation frequency--dependent changes in mitochondrial calcium in rat cardiac myocytes
1Department of Clinical Physiology, Medical Center of Postgraduate Education, Marymoncka 99, 01-813, Warsaw, Poland. bohdanp@cmkp.edu.pl
Abstract:
We investigated in the single myocytes of rat heart the effect of blocking of ATP-ase of sarcoplasmic reticulum (SR) on mitochondrial Ca2+ uptake and release. Mitochondrial Ca2+ content was investigated as Mn(2+) - resistant fluorescence of Indo 1 - AM loaded into cells. SR ATP-ase was blocked with 10(-6) M thapsigargin (Tg). Tg blocked almost completely stimulation -dependent mitochondrial Ca2+ uptake and slowed down its release despite that the maximal cytosolic Ca2+ concentration was not decreased. We propose that mitochondrial stimulation -dependent Ca2+ uptake is greatly enhanced by [Ca2+] built by SR in microdomains adjacent to these organelle.
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