Oxidative stress adaptation improves postischemic ventricular recovery
Adaptation to various forms of stress has been found to be associated with increased cellular tolerance to myocardial ischemia. In this study, the effects of myocardial adaptation to oxidative stress was examined by injecting rats with endotoxin (0.5 mg/kg) and its non-toxic derivative, lipid A (0.5 mg/kg). Both compounds exerted oxidative stress within 1 h of treatment as evidenced by enhanced malonaldehyde formation. The oxidative stress disappeared steadily and progressively with time in concert with the appearance of the induction of glutathione and antioxidative enzymes that included superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. After 24 h of endotoxin or lipid A treatment, the amount of oxidative stress and antioxidant enzyme levels were significantly lower and higher, respectively, compared to those at the baseline levels. Corroborating these results, both endotoxin and lipid A provided protection against myocardial ischemia and reperfusion injury as evidenced by significantly improved postischemic recovery of left ventricular functions. The data presented here demonstrates that a controlled amount of oxidative stress induces the expression of intracellular antioxidants that can result in enhanced myocardial tolerance to ischemia. This suggests that myocardial adaptation to oxidative stress may be a potential tool for reduction of ischemic/reperfusion injury.
Key wordsoxidative stress adaptation antioxidant reserve ischemia/reperfusion injury myocardial adaptation to ischemia endotoxin lipid A
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- 2.Maulik N, Engelman RM, Wei Zu, Lu D, Rousou JA, Das DK: Interleukin-1α preconditioning reduces myocardial ischemia reperfusion injury. Circulation 88 (suppl II): 387–394, 1993Google Scholar
- 3.Das DK, Prasad MR, Lu D, Jones RM: Preconditioning of heart by repeated stunning. Adaptive modification of antioxidative defense system. Cell Mol Biol 38: 739–749, 1992Google Scholar
- 4.Flack J, Kimura Y, Engelman RM, Das DK: Preconditioning the heart by repeated stunning improves myocardial salvage. Circulation 84 (suppl III): 369–374, 1991Google Scholar
- 6.Jenero DR, Burghardt B: Oxidative injury to myocardial membrane. Direct modulation by endogenous α-tocopherol. J Mol Cell Cardiol 21: 111–124, 1989Google Scholar
- 7.Das DK, Maulik N: Protection against free radical injury in the heart and cardiac performance. In: C.K. Sen, L. Packer, O. Hanninen (eds). Exercise and Oxygen Toxicity. Elsevier Science, Amsterdam, (in press), 1994Google Scholar
- 8.Das DK, Engelman RM: Mechanism of free radical generation in ischemic and reperfused myocardium. In: D.K. Das, W.B. Essman (eds). Oxygen Radicals: Systemic Events and Disease Processes. Krager, Basel, pp 97–128, 1990Google Scholar
- 10.Takayama K, Qureshi N, Raetz CRH: Influence of fine structure of lipid A on Limulus amebocyte clotting and toxic activities. Infect Immunol 45: 350–355, 1984Google Scholar
- 11.Repine JE: Oxidant-antioxidant balance: some observations from studies of ischemia-reperfusion in isolated perfused rat hearts. Am J Med 91: 45S-53S, 1991Google Scholar
- 12.Brown JM, Grosso MA, Terada LS, Whitman GJR, Banerjee AB, White CW, Harken AH, Repine JM: Endotoxin pretreatment increases endogenous myocardial catalase activity and decreases ischemia/reperfusion injury in isolated rat hearts. Proc Natl Acad Sci, USA 86: 2516–2520, 1989Google Scholar
- 16.Cordis GA, Bagchi D, Maulik N, Das DK: High-performance liquid chromatographic method for the simultaneous detection of malonaldehyde, acetaldehyde, formaldehyde, acetone and propionaldehyde to monitor the oxidative stress in heart. J Chromatogr 661: 181–191, 1994Google Scholar
- 19.Liu X, Engelman RM, Moraru II, Rousou JA, Flack JE, Deaton DW, Maulik N, Das DK: Heat Shock: a new approach for myocardial preservation in cardiac surgery. Circulation 86 (suppl II): 358–363, 1992Google Scholar
- 20.Homma JY, Matsuura M, Kanegasaki S, Kawakubo Y, Kojima Y, Shibukawa N, Kumazawa Y, Yamamoto A, Tanamoto K, Yasuda T, Imoto M, Yoshimura H, Kusumoto S, Shiba T: Structure requirements of lipid A responsible for the functions: a study with chemically synthesized lipid A and its analogs. J Biochem 98: 395–000, 1985PubMedGoogle Scholar