Hearts during ischemia with or without HTK-protection analysed by dielectric spectroscopy
Objective: We investigated canine hearts during ischemia after aortic cross clamping (UI, n = 20) and after HTK-cardioplegia (HTK, n = 24) at 35 °C, 25 °C, 15 °C, and 5 °C with the aim to compare tissue changes caused by the activity of anaerobic metabolism(AAM), cell membrane destruction(CD), and g...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
26 February 2018
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| In: |
Physiological measurement
Year: 2018, Volume: 39, Issue: 2 |
| ISSN: | 1361-6579 |
| DOI: | 10.1088/1361-6579/aaa575 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1088/1361-6579/aaa575 Verlag, Volltext: https://doi.org/10.1088%2F1361-6579%2Faaa575 
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| Author Notes: | Michael Schaefer, Wolfgang Gross and Martha-Maria Gebhard |
| Summary: | Objective: We investigated canine hearts during ischemia after aortic cross clamping (UI, n = 20) and after HTK-cardioplegia (HTK, n = 24) at 35 °C, 25 °C, 15 °C, and 5 °C with the aim to compare tissue changes caused by the activity of anaerobic metabolism(AAM), cell membrane destruction(CD), and gap junction uncoupling(GJU). Approach: We measured continuously the complex dielectric spectrum(DS), ATP- and lactate content, extracellular pH, and rigor contracture. To identify changes in DS caused by AAM, CD, and GJU we performed additional experiments on the gap junction-free skeletal muscle. We used heart model simulations to calculate the effect of temperature. Main results: AAM affected the DS at 10 MHz and we found a strong correlation between DS and the proton concentration with a maximum of DS at 10 mmol g−1 dry weight in ATP-concentration. The time of GJU was detected by a characteristic increase in DS and CD by a characteristic decrease at 13 kHz. In comparison to UI, GJU, AAM and CD were delayed by HTK and by hypothermia, indicating a minimization of energy consumption and an improved preservation of tissue structure. Significance: The novel findings were that in UI at 5 °C GJU occurred earlier and AAM remained constant, indicating a less effective preservation in UI by deep hypothermia in contrast to HTK. |
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| Item Description: | Gesehen am 24.05.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1361-6579 |
| DOI: | 10.1088/1361-6579/aaa575 |