Expression And Regulation Of Glucose Transporter1 In Peritoneal Mesothelial Cells Of Primary Culture

Peritoneal Dialysis ( PD) is an adequate and effective replacement therapy for the patients with end - stage renal failure. The longevity of PD depends on the long term as a dialystic membrane. During dialysis, because of continuously exposed to unphysiologic peritoneal dialysate of low PH, hyperosmolality and high glucose concentration, the PMCs serving as a biological barrier have great changes in structure and function: increase in cell volume, accumulation of extracellular matrix (ECM) under the PMCs, inhibition of cell proliferation. These lead to peritoneal fibrosis, increased glucose absorption and decreased ulrtafiltra-tion(UF). The extremely high glucose concentration in the dialysate was supposed to be the major reason.Glucose can not come through the plasma membrane lonely, must rely on the glucose transporters. Glucose transporters are the rate - limiting step in glucose uptake and utilization. Several reports indicate that glucose transporterl ( GLUT1) is the primary glucose transporter in PMCs. So, the change of GLUT1 may determine the glucose uptake in PMCs. It has been demonstrated that protein kinaseC ( PKCs) play an important role in the progression of diabetic ne-phropathy.The present study investigated the effect of high glucose and PKC activator -PMA on GLUT1 at the plasma membrane of primary cultured PMCs which might provide the theories to reduce the absorption of glucose and increase UF.Methods1. Enzymatic disaggregation used for primary culture of PMCs in male Wist-ar rats.2. Indirect immunofluorescent staining used for identification.3. Flow cytomety analysis the mean fluorescence intensity ( MFI) of GLUT1 at the plasma membrane.4. Observing the regulation effect of each treatment factor.Results1. Indirect immunofluoresent staining of confluent cells demonstrated that all cells expressed GLUTl.2. Glucose induced expression of GLUTl at the plasma membrane in a dose - dependent way. At 4.25% Glc , MFI of PMCs was 2.15 times more than thecontrol group( P < 0. 05 ) .3. High glucose stimulated the absorption of glucose in PMCs.4. PMA up-regulated GLUTl in time and dose - dependent manners. The strongest effect occurred at 24h, MFI increased 5.18 times compared to the control.5. Go6976 surpressed the overexpression of GLUTl stimulated by PMA, MFI decreased 33% (P <0. 05).Conclution1. All the PMCs express GLUTl.2. Glucose up-regulated GLUTl at the plasma membrane in a dose - dependent manner,and the absorption of glucose in PMCs also increased.3. PKC activitor - PMA increased the expression of GLUTl at the plasma membrane in time and dose - dependent manners. So, the up-regulation of GLUTl might involve in the damage of PMCs caused by high glucose.4. The inhibitor of cPKC blocked up-regulation of GLUT1 stimulated by PMA . It might be an effective method to increase UF by using inhibitor of cPKC in PD.