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Objective To investigate the impact of citreoviridin(CIT) on mRNA expression of mitochondrial respiratory chain synthesis related transcriptional regulation gene,mitochondrial membrane(MMP) potential and reactive oxygen species (ROS) in cardiomyocytes of rat.Methods Viability of rat primary cardiomyocytes treated with different concentrations of CIT (0,1,2,3,4,5,6,7,8,9,10 μmol/L) for 24 h was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.Based on the MTT curve,median inhibitory concentration(IC50) was calculated using SPSS 13.0.High-,medium-and low-dose groups of CIT(1.650,1.234,0.715 μmol/L) were defined corresponding to 99％,95％ and 90％ of cardiomyocyte viability,respectively.CIT was not added in as the control group.After 24 hours,the mRNA expression levels of peroxisome-proliferator-activated receptor γcoactivator(PGC-1α),nuclear respiratory factor 1 (Nrf1) and nuclear respiratory factor 2(Nrf2) in cardiomyocytes were detected by reverse transcriptase polymerase chain reaction(RT-PCR).Changes of MMP and intracellular ROS were determined by a fluorescence microplate reader using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) and 2,7-dichlorofluorescein diacetate (DCFH2-DA) as fluorescent probes.Results Compared with 0 μmol/L CIT group [(89.4 ± 17.6)％],viabilities of rat primary cardiomyocytes treated with 2-10 μmol/L CIT groups[(80.2 ± 20.2)％,(74.4 ± 18.7)％,(63.2 ± 8.9)％,(51.5 ± 18.8)％,(39.0 ± 15.7)％,(22.6 ± 10.5)％,(19.9 ± 4.9)％,(20.7 ± 4.8)％,(18.5 ± 3.3)％] decreased significantly(all P ＜ 0.05).The IC50 value of cardiomyocytes after24 h treatment with CIT was 4.6 μmol/L The PGC-1α mRNA expressions ofhigh-,medium-and low-dose groups(0.431 ± 0.041,0.619 ± 0.031,0.653 ± 0.037) were significantly lower compared to that of the control group(0.776 ± 0.081,all P ＜ 0.05).The Nrf1 mRNA expression of high-dose group(0.358 ± 0.05) was significantly lower compared to that of the control group(0.580 ± 0.098,P ＜ 0.05).Nrf2 mRNA expressions of the high-and medium-dose groups(0.352 ± 0.041,0.472 ± 0.011) were significantly lower than that of the control group (0.667 ± 0.091,all P＜ 0.05).Compared with the control groups[(100.00 ± 0.00)％,(100.00 ± 0.00)％],the MMP levels of high-,medium-and low-dose groups[(55.3 ± 3.3)％,(69.8 ± 4.7)％,(81.8 ± 2.7)％] were significantly lower and the ROS levels[(606.0 ± 46.3)％,(275.0 ± 53.5)％,(158.9 ±29.5)％] were significantly higher(all P ＜ 0.05).Conclusions CIT inhibits the biosynthesis of mitochondria in primary cardiomyocytes and induces oxidative stress.Myocardial injury is caused by cardiomyocyte apoptosis through mitochondrial pathway,which leads to myocardial injury.
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ObjectiveTo observe the morphological feature of myocardial changes in adult rat exposed to citreoviridin(CIT) with selenium and protein deficiency.MethodsAccording to 2 × 2 factorial design,48 healthy male Wistar rats aged 4-week were randomly divided into four groups:group Ⅰ (Se-Pro-CIT+,low selenium and low protein plus CIT group),group Ⅱ (Se-Pro-CIT-,low selenium and low protein without CIT group),group Ⅲ (Se+Pro+CIT+,adequate selenium and adequate protein plus CIT group),and group Ⅳ (Se+Pro+CIT-,adequate selenium and adequate protein without CIT group),12 rats in each group.After one week of normal adaptive feeding,all the rats were fed with selenium and protein deficiency feed for 2 months,and then the animals in group Ⅰ and group Ⅲwere fed with 8 mg·kg-1 ·d-1 of CIT for 2 more months,after that the CIT dose was increased to 10 mg·kg-1 ·d-1 for the final 2 weeks.At the end of the experiment,all the rats were sacrificed by femoral artery bleeding,and body and heart weight were measured.Heart weight index was calculated and histopathological changes were observed under light microscope.Results Heart weight indexes of the 4 groups(Se-Pro-CIT+,Se-Pro-CIT-,Se+Pro+CIT+ and Se+Pro+CIT- groups) were (3.65 ± 0.45) × 10-3,(3.05 ± 0.19) × 10-3,(3.83 ± 1.06) × 10-3 and (3.31 ± 0.52) × 10-3,respectively.The results of factorial analysis showed that the effects of CIT on heart weight index were statistically significant(F =8.524,P ＜ 0.05 ),the effects of Se + Pro were not statistically significant(F =1.347,P ＞ 0.05),and there were no interactions between the two factors (F =0,048,P ＞ 0.05).Morphologically,tissue fibrosis around branch coronary artery in group Ⅰ rats,plenty of cardiocyte pycnosis in group Ⅱ,and myocardial scattered necrotic foci in group Ⅲ were observed,accompanied by inflammatory cell infiltration in group Ⅲ,and normal myocardial structure in group Ⅳ rats.Conclusions Citreoviridin plays a major role in causing myocardial injury( degeneration and necrosis) and CIT combined with selenium and protein deficiency can aggravate the
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ObjectiveTo clarify the causative effect of citreoviridin toxins(CIT) as well as nutritional deficiency of selenium and protein on rat myocardial injury at biochemical level.Methods According to 2 × 2 factorial design,48 healthy male Wistar rats aged 4-week were randomly divided into four groups:exposed to CIT along with nutritional deficiency of selenium and protein,nutritional deficiency of selenium and protein,exposed to CIT and control groups.After the rats in each group began to be fed with selenium and protein deficiency and(or) adequate fodder for 3 months,8 mg/kg body weight of CIT was fed daily to the rats in the two CIT toxin groups for two months.After that the CIT dose was raised up to 10 mg/kg body weight each day within the final 2 weeks.At the experimental endpoint,all the rats were sacrificed by femoral artery bleeding after ether anesthesia,and serum and heart specimens were collected for biochemical analysis by detecting serum Tn-Ⅰ and albumin,serum activities of CK and GSH-Px,myocardial SOD and T-AOC.ResultsThe interactions between Se & protein and CIT in rat final body weight,serum albumin,and Tn-Ⅰ was observed(F=8.186,6.160,19.183,all P＜ 0.05),whereas interactions in rat body weight of 12 weeks,serum GSH-Px,CK as well as myocardial SOD,T-AOC activity were not found (F=1.633,1.987,0.075,0.474,1.145,all P ＞ 0.05).Under the nutritional deficiency of selenium and protein,serum albumin and Tn-Ⅰ level in the groups with CIT toxin[ (42.88 ± 1.19) g/L,(668.6 ± 55.8) ng/L,respectively]were lower than that of the group without CIT toxin[ (47.59 ± 1.05)g/L,(989.3 ± 49.2)ng/L,respectively,all P ＜0.05].The main effects of selenium and protein on rat body weight of 12 weeks,serum GSH-Px,myocardial SOD and T-AOC were statistically significant between different groups (F =96.860,58.086,4.475,25.485,all P ＜ 0.05).Rat body weights of 12 weeks in the two groups of nutritional deficiency of selenium and protein[ (186.33 ± 7.89),(197.83 ± 7.89)g] were all lower than others[ (274.08 ± 7.89),(265.42 ± 7.89)g,all P ＜ 0.05]; serum GSH-Pxs in the two groups of nutritional deficiency of selenium and protein[ (317.5 ± 102.6),(296.9 ± 90.5)U/L] were all lower than others[ (926.1 ± 110.9),( 1181.7 ± 85.9)U/L,all P ＜ 0.05] ; myocardial SODs in the two groups of nutritional deficiency of selenium and protein [ (65.22 ± 5.91 ) × 106, (62.68 ± 5.61 ) × 106 U/kg] were all lower than others [(74.07 ± 7.24) × 106, (80.07 ± 5.91) × 106 U/kg,all P＜ 0.05]; myocardial T-AOCs in the two groups of nutritional deficiency of selenium and protein[ (1.138 ± 0.086) × 106,(0.806 ± 0.081 ) × 106 U/kg] were all lower than others[(1.688 ± 0.105) × 106,(1.163 ± 0.086) × 106 U/kg,all P ＜ 0.05].Conclusions Animal model with selenium and protein deficiency is successfully established.However,the results of biochemical index tested in the experimental rats show no regularity effect,which needs to be checked again in the future study.
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Objective To ohserve the rat myocardial damage induced by citreoviridin(CIT)in the status of combined selenium and protein deficiency.Methods According to 2×2 factorial design,forty 4-week-old healthy Wistar rats were randomly divided into four groups.i.e.combined selenium and protein adequate with no CIT and with some CIT groups(Se+Pro+CIT-.Se+Pro+CiT+),combined selenium and protein deficiency with no CIT and with some CIT groups(Se-Pro-CIT-,Se-Pro-CIT+).The numbers of male and female were fifty-fifty.Theserats were fed with combined selenium and protein adequate and combined selenium and protein deficiency fodder until the 16th week. Cardiac toxicity of CIT was evaluated by general state of health, heart weight index, myocardial pathological change, the levels of selenium and the activities of glutathion peroxidase (GSH-Px) and creatine kinase (CK) in serum, and the activity of superoxide dismutase(SOD) of myocardium. Results The interaction effects of combined selenium and protein deficiency and adequate CIT on body weight, serum levels of selenium and albumin, heart weight index, the activities of CK and GSH-Px in serum and SOD of myocardium were statistically not significant(F= 0.000, 1.210, 0.625, 0.981, 2.785, 0.074, 0.001, all P> 0.05). The main effects of combined selenium and protein on the levels of serum selenium and albumin, heart weight index and the activity of GSH-Px in serum were statistically significant(F = 507.698, 87.734, 4.201, 109.389, all P < 0.05). The main effects of CIT on body weight, the levels of serum selenium and albumin, heart weight index and the activity of CK in serum were statistically significant(F = 10.929, 4.371, 26.108, 24.844, 4.439, all P < 0.05). The mean levels of serum selenium of Se-Pro- groups [(70.4 ± 40.0), (87.7 ± 59.6 )μg/L] were lower than those of Se+Pro+ groups [(446.1 ± 74.8),(502.1 ± 39.2)μg/L, all P < 0.05]. The mean levels of serum albumin of Se-Pro- groups [(34.36 ± 1.28 ), (33.38 ±2.48)g/L] were lower than those of Se+Pro+ groups[(40.69 ± 1.30), (38.71 ± 2.15)g/L, all P < 0.05]. The mean levels of heart weight index of CIT+ groups[(4.14 ± 0.36) × 10-3, (4.39 ± 0.53) x 10-3] were higher than those of CIT-groups[(3.56 ± 0.26) x 10-3, (3.80 ± 0.28) x 10-3, all P < 0.05] respectively at the same levels of selenium and protein. The mean levels of CK in serum of Se-Pro-CIT+ group[(2.54 ± 0.56)kU/L] was lower than that of Se-Pro-CIT- group [(3.37 ± 0.67 )kU/L, P < 0.05]. The mean levels of activity of GSH-Px in serum of Se-Progroups[(408.1 ± 412.6), (510.5 ± 392.0)U/L] were lower than those of Se+Pro+ groups[(1667.8 ± 102.2),(1731.5 ± 144.4)U/L, all P < 0.05]. In Se+Pro+CIT+ group, there was part of intercalary disc of cardiac myocytes fragmented;the conjunctions between myoeytes were broken;in some region, cardiac myocytes became edematous,even dissolved. In Se-Pro-CIT- group, the change of cardiac myocytes membrane structures was not obvious;filament structure was disappeared around nucleus;deposition of mass floccule could be seen. In Se-Pro-CIT+ group,the structure of sarcomeres was not obvious;mitochondrial cristae was loosened;cavities in myocytes could be seen occasionally;there were lots of disseminated sareoplasmic reticulum extending. Conclusions .CIT is the main risk factor in inducing myocardial damage. The deficiency of combined selenium and protein can aggravate the damage,but its independent pathogenic effect is weak.