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Updated: Sep 23, 2026

Optical Mapping of Intra-Sarcoplasmic Reticulum Ca2+ and Transmembrane Potential in the Langendorff-perfused Rabbit Heart
Published on: September 10, 2015
Sarcoplasmatic reticulum function in the ischemic myocardium
J Blom1, P D Verdouw, J M Lamers
1Department of Biochemistry, Erasmus University Rotterdam, The Netherlands.
Abstract:
The effects of different periods of myocardial ischemia on sarcoplasmatic reticulum function were studied in porcine hearts in which successive occlusions of branches of the left anterior descending coronary artery yielded myocardium ischemic for 0.5, 1 or 2 h. Sarcoplasmatic reticulum vesicles were isolated from transmural biopsies of control and ischemic segments. Ca2+ pumping ATPase was already impaired after 0.5 h of ischemia (77 +/- 9% of control, n = 5) and had decreased to 44 +/- 9% of control (n = 4) after 1 h of ischemia. The functional damage caused by ischemia may be related to an altered second messenger control of the Ca2+ pump because the in vitro phosphorylation of phospholamban by catalytic subunit was also reduced.
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