Chen-Hsiu Chen1, Chih-Wei Wu2, Cheng-Dean Shih3, Wei-Hung Lien2, Shiao-Lin Huang2, Cheng-Cheng Huang4. 1. Department of Anesthesiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan. 2. Department of Anesthesiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan. 3. Department of Pharmacy and Master Program, Tajen University, Pingtung, Taiwan. 4. Department of Anesthesiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan. Electronic address: kent7892002@msn.com.
Abstract
OBJECTIVES: To evaluate the efficiency of isoflurane-induced anesthetic preconditioning and the role of mitochondrial manganese superoxide dismutase (MnSOD) in hypertensive hypertrophied hearts. DESIGN: A prospective animal investigation. SETTING: Medical center hospital research laboratory. PARTICIPANTS: Male spontaneously hypertensive rats (SHRs) and normotensive control Wistar-Kyoto (WKY) rats. INTERVENTIONS: All pentobarbital-anesthetized open-chest rats were subjected to a 45-minute left coronary artery occlusion followed by a 120-minute reperfusion. Before ischemia, both SHR and WKY rats were assigned randomly to receive a 30-minute exposure to 0.9% saline or 1.0 minimum alveolar concentration isoflurane. MEASUREMENTS AND MAIN RESULTS: The myocardial infarct size, assessed as a percentage of the area at risk, was significantly greater in the hypertrophied SHRs than in the WKY rats (65.3%±8.7% v 51.8%±7.2%, p<0.05). Isoflurane preconditioning appreciably reduced the infarct size in the WKY hearts (30.9%±10.5%, p<0.05) but not in the SHR hearts. MnSOD protein expression and enzymatic activity were increased drastically in response to isoflurane exposure in the hearts of the WKY rats (p<0.05) but not in the SHRs. CONCLUSIONS: Isoflurane-induced anesthetic preconditioning is attenuated in hypertensive hypertrophied hearts. This impairment may be associated with the loss of MnSOD augmentation during ischemia and reperfusion.
OBJECTIVES: To evaluate the efficiency of isoflurane-induced anesthetic preconditioning and the role of mitochondrial manganese superoxide dismutase (MnSOD) in hypertensive hypertrophied hearts. DESIGN: A prospective animal investigation. SETTING: Medical center hospital research laboratory. PARTICIPANTS: Male spontaneously hypertensiverats (SHRs) and normotensive control Wistar-Kyoto (WKY) rats. INTERVENTIONS: All pentobarbital-anesthetized open-chest rats were subjected to a 45-minute left coronary artery occlusion followed by a 120-minute reperfusion. Before ischemia, both SHR and WKY rats were assigned randomly to receive a 30-minute exposure to 0.9% saline or 1.0 minimum alveolar concentration isoflurane. MEASUREMENTS AND MAIN RESULTS: The myocardial infarct size, assessed as a percentage of the area at risk, was significantly greater in the hypertrophied SHRs than in the WKY rats (65.3%±8.7% v 51.8%±7.2%, p<0.05). Isoflurane preconditioning appreciably reduced the infarct size in the WKY hearts (30.9%±10.5%, p<0.05) but not in the SHR hearts. MnSOD protein expression and enzymatic activity were increased drastically in response to isoflurane exposure in the hearts of the WKY rats (p<0.05) but not in the SHRs. CONCLUSIONS:Isoflurane-induced anesthetic preconditioning is attenuated in hypertensive hypertrophied hearts. This impairment may be associated with the loss of MnSOD augmentation during ischemia and reperfusion.