Christopher Lotz1, Jan Stumpner2, Thorsten M Smul2. 1. Department of Anesthesia and Critical Care, University of Würzburg, Germany. Electronic address: Lotz_C@ukw.de. 2. Department of Anesthesia and Critical Care, University of Würzburg, Germany.
Abstract
BACKGROUND: Pharmacological interventions reducing myocardial ischemia and reperfusion (I/R) injury include the administration of anesthetics. Both sevoflurane as well as propofol have been shown to elicit cardiac protection via distinct molecular mechanisms. We investigated the hypothesis that sevoflurane in contrary to propofol anesthesia elicits cardiac protection against I/R-injury via mitochondrial mechanisms of disease. METHODS: Male New Zealand white rabbits (n = 42) were subjected 30 min of coronary artery occlusion followed by 3 h of reperfusion. After induction with pentobarbital, the animals either received sevoflurane or propofol to maintain general anesthesia. Infarct size was determined gravimetrically after triphenyltetrazolium chlorid-staining. Cardiac mitochondria were isolated and mitochondrial oxygen consumption was measured using a Clark electrode. Mitochondrial respiratory chain complex activities (I-IV) were analyzed utilizing specific assays. Data are mean ± SD. RESULTS: Sevoflurane anesthesia significantly decreased the resulting myocardial infarct size compared to propofol anesthesia (p = 0.0275 vs. propofol). Mitochondria from animals receiving propofol anesthesia showed a significantly reduced mitochondrial respiratory control ratio (p = 0.01909 vs. sham) and impaired activities of respiratory complex I (p = 0.0147 vs. sham; p < 0.01 vs. sevoflurane) as well as respiratory complex IV (p = 0.0181 vs. sham). Mitochondrial dysfunction was absent in sevoflurane anesthesized animals. Furthermore, a significantly higher portion of complex I was found to be in its deactive form during I/R-injury in animals receiving sevoflurane anesthesia (p = 0.0123 vs. propofol). CONCLUSIONS: Sevoflurane as opposed to propofol anesthesia preserved mitochondrial respiration and elicited cardiac protection against I/R-injury.
BACKGROUND: Pharmacological interventions reducing myocardial ischemia and reperfusion (I/R) injury include the administration of anesthetics. Both sevoflurane as well as propofol have been shown to elicit cardiac protection via distinct molecular mechanisms. We investigated the hypothesis that sevoflurane in contrary to propofol anesthesia elicits cardiac protection against I/R-injury via mitochondrial mechanisms of disease. METHODS: Male New Zealand white rabbits (n = 42) were subjected 30 min of coronary artery occlusion followed by 3 h of reperfusion. After induction with pentobarbital, the animals either received sevoflurane or propofol to maintain general anesthesia. Infarct size was determined gravimetrically after triphenyltetrazolium chlorid-staining. Cardiac mitochondria were isolated and mitochondrial oxygen consumption was measured using a Clark electrode. Mitochondrial respiratory chain complex activities (I-IV) were analyzed utilizing specific assays. Data are mean ± SD. RESULTS:Sevoflurane anesthesia significantly decreased the resulting myocardial infarct size compared to propofol anesthesia (p = 0.0275 vs. propofol). Mitochondria from animals receiving propofol anesthesia showed a significantly reduced mitochondrial respiratory control ratio (p = 0.01909 vs. sham) and impaired activities of respiratory complex I (p = 0.0147 vs. sham; p < 0.01 vs. sevoflurane) as well as respiratory complex IV (p = 0.0181 vs. sham). Mitochondrial dysfunction was absent in sevoflurane anesthesized animals. Furthermore, a significantly higher portion of complex I was found to be in its deactive form during I/R-injury in animals receiving sevoflurane anesthesia (p = 0.0123 vs. propofol). CONCLUSIONS:Sevoflurane as opposed to propofol anesthesia preserved mitochondrial respiration and elicited cardiac protection against I/R-injury.