Hearts during ischemia with or without HTK-protection analysed by dielectric spectroscopy

• Verfasst von: Schäfer, Michael [VerfasserIn]
• Verfasst von: Gross, Wolfgang [VerfasserIn]
• Verfasst von: Gebhard, Martha-Maria [VerfasserIn]
• Titel: Hearts during ischemia with or without HTK-protection analysed by dielectric spectroscopy
• Verf.angabe: Michael Schaefer, Wolfgang Gross and Martha-Maria Gebhard
• E-Jahr: 2018
• Jahr: 26 February 2018
• Teil: volume:39
• Teil: year:2018
• Teil: number:2
• Fussnoten: Gesehen am 24.05.2019
• Titel Quelle: Enthalten in: Physiological measurement
• Ort Quelle: Bristol : IOP Publ., 1980
• Jahr Quelle: 2018
• Band/Heft Quelle: 39(2018,2) Artikel-Nummer 025002, ? Seiten
• ISSN Quelle: 1361-6579
• DOI: doi:10.1088/1361-6579/aaa575
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1666283436

Abstract

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.