Expression And Significance Of MDR2 Gene In Hyperlipidemic Rats

Abstract:Objective:Studying on the expression of MDR2 gene and Pgp3 in hyperlipidemic rats, To explore the expression and Significance between the MDR2 gene and Pgp3 in liver cell, so as to provide a new theory foundation and molecular basis about how to prevent and control Hyperlipidemic.Methods:20 healthy adult male Spague-Dawlay (SD) rats were divided into two groups randomly after Adaptive feeding one week, normal control group (A group) 10 rats, the model group (B group) 10 rats. The normal diet group was fed with the foundation feed, the model group was fed with high-fat diet,drank water freely. According to pre-test results, after feeding 6 weeks, both control group and model group were killed,Blood was collected through Automatic biochemical analyzer to determinated rat's blood lipid and serum aminopherase in each group inculded TG,TC,ALT,AST.Model is successful, through Sodium pentobarbital anesthesia, Then the liver was taken out rapidly to take it's wet weight, the liver index was calculated as follows:liver wet weight/body mass×100%. And in the middle of the left lobe of liver was cut into 1cm×1cm×1cm as samples,one placed in 10% formalin fixed and paraffin sections; the other placed Sterile cryopreservation tubes, and to group numbers,-70℃cryopreservation standby. The liver tissue samples were taken to preparate paraffin sections. The liver tissue pathological changes were observed through the hematoxylin-eosin (HE) staining under light microscope and the degree of liver fibrosis was detected. the expression of protein of pgp3 in liver tissue were examined by immunohistochemistry,By image analysis system, integrated optical density was analyzed.the expression of MDR2 mRNA in the liver tissue was detected by RT-PCR method (reverse transcription-Polymerase Chain reaction). the gray value was analyzed by Biod-rad softwares.Gray ratio represents expression amount of MDR2 mRNA Optical density value denotes protein expression amount of Pgp3. Measuring data was demonstrated with mean±standard deviation (x±s), using t test. the groups were compared with variance analysis. Count data was used chi-square test; Test level a= 0.05, the difference of P<0.05 has statistical significance.Results:All 20 rats were entered into the final analysis.(1) the body weight, liver index, serum lipid and transaminase levels of the model group rat were significantly increased; fatty change in liver tissue,the fibrosis performance of a small number.TC in the model group was(3.32±0.20)mmol/L, significantly higher than that of the control group(1.86±0.15) mmol/L (p＜0.05). TG in the model group was(1.92±0.28)mmol/L, significantly higher than that of the control group(0.78±0.16)mmol/L (p＜0.05). liver index in the model group was(3.03±0.29)%, significantly higher than that of the control group(2.28±0.39)%(p＜0.05). (2) the immunity histochemistry staining method showed that the expressions of Pgp3 in liver were dyed yellowish brown under the high power objective. With integral optical density (IOD) for analysis, IOD in the model group was(14.41±6.33), significantly higher than that of the control group (6.70±0.82) (P＜0.05). The difference between the two groups was statistically significant.(3) the expression of MDR2 mRNA in the liver tissue was detected by RT-PCR method (reverse transcription-Polymerase Chain reaction). MDR2 gene amplification in the model with significantly higher brightness. RT-PCR showed that the mRNA expressions of MDR2 gene in the model group (2.23±0.38)were significantly Higher in hyperlipidemic rats than those Normal control group(0.70±0.18)(P＜0.05).Results:(1) the model was successfully constructed, in hyperlipidemic rats, transaminase increased Significantly Liver function was damaged in Varying degrees. Steatosis was Notable And even liver fibrosis (2). expression of MDR2 gene in hyperlipidemic rats was increased, (3). In hyperlipidemic rats,expression of MDR2 gene and Pgp3 in hyperlipidemic rats was increased, Therefore, we speculate Pgp3 liver cells as a transporter of lecithin and its expression significantly increased the concentration of lecithin will, thus contributing to lipid metabolism.