ABSTRACT
<p><b>AIM</b>To set up an IR-HIRc cell model for screening the inhibitor of GFAT (glutamine: fructose-6-phosphate amidotransferase) , the key enzyme in the hexosamine biosynthesis pathway (HBP).</p><p><b>METHODS</b>For GFAT activity assay, the GDH method was improved by adjusting the value of pH in the reaction system and the concentrations of the reactants. The sensitivity to insulin in the cells was estimated by the measurement of insulin-induced glucose-uptake. The IR-HIRc model was set up by the stimulation of long-action insulin for 36 h. The IR-HIRc model and GDH method was used for screening GFAT inhibitor.</p><p><b>RESULTS</b>With the administration of 25 nmol x L(-1) long-action insulin in HIRe cells for 36 hours, the GFAT activity increased by 47% and the insulin-induced glucose-uptake decreased by 21%. Azaserine, a GFAT inhibitor, inhibited GFAT activity significantly in a dose-dependent manner in IR-HIRc model.</p><p><b>CONCLUSION</b>With the stimulation of 25 nmol x L(-1) long-action insulin for 36 h, excess hexosamine flux and insulin resistant in IR-HIRc cell model was set up, which can be used for screening</p>
Subject(s)
Animals , Rats , Azaserine , Pharmacology , Cell Line , Dose-Response Relationship, Drug , Fibroblasts , Cell Biology , Metabolism , Glucose , Metabolism , Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) , Metabolism , Hexosamines , Insulin , Pharmacology , Insulin Resistance , Models, Biological , Recombinant Proteins , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study the effects of L.F04, the active fraction of Lycopus lucidus, on erythrocytes rheological property so as to investigate its mechanism in promoting blood circulation and removing blood stasis.</p><p><b>METHOD</b>The effects of L.F04 (used for treatment for 10 days in different dosages) on deformability, aggregation and membrane liquidity of erythrocytes (MLE) as well as whole blood apparent viscosity (eta(b)) were examined on the basis of rat model of blood-stasis syndrome induced by venous injection of high molecular weight dextran.</p><p><b>RESULT</b>As compared with the normal control group, the model group's RBC deformability and MLE were lower, and the aggregation of erythrocytes and eta(b) were higher. Compared with the model group, both L.F04 0.612 g/kg and 0.306 g/kg showed significant effect in improving deformability and inhibiting aggregation of red blood cells (RBC) and reducing blood viscosity. The trend of improving MLE was also shown.</p><p><b>CONCLUSION</b>L.F04 could significantly improve the abnormal rheological property of erythrocytes.</p>