Expression of 8-hydroxy-2-deoxy guanosine, thioredoxin reductase 1 and glutathione peroxidase 1 in myocardium of autopsy patients with Keshan disease / 中国地方病学杂志

Objective In this study,we investigated the relationship between oxidative stress,selenoproteins level and onset of Keshan disease (KD) through detecting the expression of 8-hydroxy-2-deoxy guanosine (8-OH-dG),thioredoxin reductase 1 (TrxR1) and glutathione peroxidase 1 (GPx1) in myocardial tissue.Methods Myocardium samples of autopsy patients including 8 cases of KD (KD group included 4 acute KD and 4 chronic KD) and 9 cases of non-KD (control group) were immunohistochemically stained for 8-OH-dG,TrxR1 and GPx1.The staining intensities subsequently quantified by using Olympus Image-Pro Plus 6.0 software.Results The positive rate of 8-OH-dG expression in myocardial nuclei was higher in the case group[(68.6 ± 20.4)％] than that of the control group[(2.4 ± 1.5)％,t =8.515,P ＜ 0.05].In addition,the positive rate of 8-OH-dG expression in acute KD[(91.7 ± 3.7)％] was significantly higher than that of chronic KD[(53.2 ± 7.9)％,t =6.409,P＜0.05].The distribution of TrxR1 and GPx1 was not associated with the distribution of myocardial damage.The expression of these two selenoproteins in KD group (401340 ± 59865,497590 ± 197082) were both lower than that of control group(2790300 ± 379298,1348400 ±615840; t =-28.493,-6.016,respectively,all P＜0.01).Conclusions Oxidative damage is detected in myocardium tissue of KD,and 8-OH-dG expression is associated with the degree of myocardial damage in KD.Selenoproteins,TrxR1 and GPx1,may be closely related to the pathogenesis of KD.

Role of peroxisome proliferator-activated receptor alpha activation in acute myocardial damage induced by isoproterenol in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Peroxisome proliferator-activated receptor (PPAR) alpha is one of the subtypes of PPARs. It regulates metabolism of lipid and lipoprotein, as well as glucose homeostasis. In addition, PPARalpha influences cellular proliferation, inflammation, differentiation and apoptosis, which plays a vital role in cardiovascular diseases. The purpose of this study was to investigate the role and mechanisms of PPARa activation in relation to acute myocardial damage induced by isoproterenol in rats.</p><p><b>METHODS</b>Thirty male Wister rats were randomly divided into control group, isoproterenol (Iso) injured group and fenofibrate (FF) treatment group. Acute myocardial damage caused by isoproterenol intraperitoneal injection induced ischemia was established. We determined the levels of creatine kinase (CK) and lactic dehydrogenase (LDH) in serum as well as the concentrations of free fatty acids (FFA) in serum and myocardium. The mRNA expressions of PPARa, muscular type carnitine palmitransferase (M-CPT-I) and medium chain lipid acetyl coenzyme A dehydrogenase (MCAD) were analyzed by reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Compared with the control group, the levels of serum CK and LDH were significantly increased after FF and Iso treatments. Moreover, the concentrations of FFA in both serum and myocardium were obviously increased in the Iso group and FF group, while the mRNA expressions of PPARalpha, M-CPT-I and MCAD declined, respectively (P < 0.01). When compared with the Iso group, significant decreases in serum CK and LDH were observed in the FF group. The concentrations of FFA both in serum and myocardial tissue were markedly decreased in the FF group, while the expressions of PPARalpha, M-CPT-I and MCAD mRNA were increased (vs. Iso, P < or = 0.01).</p><p><b>CONCLUSIONS</b>The utilization of FFA was reduced in isoproterenol induced acute myocardial damage. PPARalpha activation by its activator fenofibrate may play a key role in energy metabolism in acute myocardial damage induced by isoproterenol in rats.</p>

Protective effects of peroxisome proliferate-activated receptor α activation on acute myocardial damage / 中国地方病学杂志

Objective To investigate the protective effects and molecular mechanism of peroxisome proliferate-activated receptor α(PPARα) activation on acute myocardial damage induced by isoproterenol (Iso) in rats. Methods Thirty male Wistar rats, weighting 160～180 g, were randomly divided into control group, Iso group, fenafibrate(FF) group(each n=10) according to physique quantity. Acute myocardial injury caused by Iso abdomen cavity injection induced ischemia was established and the protective effects of peroxisome proliferate-activated receptor α activation were accessed by the level of ereatine kinase(CK), lactic dehydrogenase(LDH) in serum as well as the activities of myoperoxidase(MPO) in myocardium, and the protein expressions of PPABα in myocardium by Western blot. Results The level of serum CK in control group, lso group and FF group, was (62.41±9.47),(101.71±11.05),(75.64±11.73)kU/L, respectively(F= 34.34, P<0.01). Whereas the level of serum CK in Iso group and FF group was higher than that in control group(P<0.01 or<0.05), the level of serum CK in FF group was lower than that in Iso group(P<0.01). The levels of LDH in these three groups were (5912.20±204.44), (6365.78±137.10), (6089.76±169.60) U/L, respectively(F= 17.54, P<0.01). Compared with the control group, the levels of LDH in Iso and Fir groups were significantly increased(P<0.01 or<0.05). But the level of LDH in FIr group was decreased compared with that in Iso group(P<0.01). The activities of myocardial MPO in these three groups were (1.95±0.10),(3.89±0.17),(2.49±0.19)U/g, espectively(F=391.68,P< 0.01). The activities of myocardial MPO in Iso and FF groups were higher than that in the control group (all P< 0.01), while the activities of myocardial MPO in FIr group were lower than that in lso group(P<0.01). The protein expressions of PPARα in myocardium of these three groups were 251.57±10.95,191.97±10.74,215.08±9.61, respectively(F=82.69, P<0.01). Conclusion PPARα activation by its actor FF can exert protective effects on the acute myocardial ischemia injury induced by lso in rats through inhibiting the release of inflammatory cell factors.