Effect of selenium, protein and vitamin E deficiency on mRNA expression of rat cardiac selenoprotein / 中国地方病学杂志

ABSTRACT

ObjectiveTo explore the effect of selenium,protein and vitamin E deficiency on mRNA expression of rat cardiac selenoprotein,and their relation with myocardial injury.MethodsForty male Wistar rats were randomly divided into 4 groupslow selenium low protein low vitamin E group(group A),low selenium low protein adequate vitamin E group(group B),adequate selenium adequate protein low vitamin E group(group C),and adequate selenium adequate protein adequate vitamin E group (group D),10 rats in each group.The activity of whole blood glùtathione peroxidase(GSH-Px ) was measured using dithiobis nitrobenzoic acid (DTNB) at the end of sixth month experiment.The levels of mRNA expression of glutathione peroxidase 1(Gpx1),phospholipid hydroperoxide glutathione peroxidase 4(Gpx4),thioredoxin reductase(TrxR),selenoprotein P(Se-P) and selenoprotein W(Se-W) were determined by real-time fluorescence quantitative PCR at the end of sixth month.Histopathological changes of myocardial injury were observed with light microscope.ResultsThe activity of GSH-Px was (44.6 ± 3.1 ),(45.5 ± 1.6),(86.6 ± 2.2),(85.6 ± 1.2)U/L,respectively,in the above four groups at the end of sixth month,and the difference was statistically significant(F =100.7,P ＜ 0.01 ) ; the activity of GSH-Px of groups C and D was higher than that of groups A,B(all P ＜ 0.05).mRNA expression of myocardial tissue of the four groups was as follows,Gpx1(0.099 ± 0.312,0.054 ± 0.007,0.386 ± 0.067,0.340 ± 0.085),Gpx4(1.005 ± 0.089,0.810 ± 0.229,0.895 ± 0.084,0.922 ± 0.399),and Se-W(0.188 ± 0.080,0.119 ± 0.069,0.574 ± 0.167,0.570 ± 0.383),and the difference was statistically significant(F =112.1,3.76,22.8,all P ＜ 0.05) ; the mRNA levels of Gpx1,Se-W of groups C,D were significantly higher than that of groups A,B(all P ＜ 0.05).The mRNA expression of Gpx4 of group A was higher than that of group C(P ＜ 0.05).The mRNA expression of TrxR(0.130 ± 0.037,0.127 ± 0.038,0.134 ± 0.021,0.120 ± 0.014) and Se-P(0.446 ± 0.155,0.413 ± 0.152,0.385 ± 0.041,0.408 ±0.208 ) was not statistically different among the four groups (F =0.91,1.75,all P ＞ 0.05).Pathological changes of myocardial tissue were mainly as foci of coagulative necrosis.The necrosis detection rate of the four groups was 8/10,4/9,2/10,and 1/10,respectively,and the difference was significant statistically(Fisher exact test,P =0.0067).ConclusionsLong-term selenium,protein and vitamin E deficiency will reduce body antioxidant capacity and lead to myocardial injury.The mRNA levels of Gpx1 and Se-W and selenium level are closely related.The mRNA levels of Gpx4,TrxR and Se-P remain relatively stable.