Molecular Mechanism Of Ameliorative Effects Of Rat Serum With Rhizoma Coptidis And Radix Rehmanniae On The Damage Of NIT-1β Cell Induced By Palmitate

objectiveTo observe the effect of rat serum with rhizoma coptidis, radix rehmanniae andtheir combination on the apoptosis and GSIS dysfunction of NIT-1cell induced bypalmitate as so as to reveal the effect mechanism of lipotoxicity caused by palmitate inpancreatic β cell can be reduced by rat serum with rhizoma coptidis and radixrehmanniae throng the two aspects of cells apotosis and GSIS of β cell.MethodsPart1Effect of rat serum with rhizoma coptidis, radix rehmanniae on the apoptosisof NIT-1cell induced by palmitate0.25mmol/L PA interacted with NIT-1cell for24h. Model group, serum ofrhizoma coptidis group（SRC）, serum of radix rehmanniae group（SRR）, serum of rhizomacoptidis-radix rehmanniae group（SRCRR）, Repaglinide group（REP）, the controled groupand the normal serum group（NS） were prepared, Using Annexin V-PI double labelingmethod to detect the apotosis of cells with the technique of flow cytometry.Part2Effect of rat serum with rhizoma coptidis, radix rehmanniae on the GSISdysfunction of NIT-1cell induced by palmitateGlucose stimulated insulin secretion （GSIS） test was done with KRBH solution containing2.8mmol/L glucose and KRBH solution containing16.7mmol/L glucose.ATP/ADP was measured by the bioluminescent kit. The current of beta cell K+ATPchanneland Ca²⁺channels detected by patch clamp. Laser confocal microscope measured Ca²⁺concentration inside the cell.Insulin concentration was measured by radioimmunoassay.ResultsPart1Effect of rat serum with rhizoma coptidis, radix rehmanniae on the apoptosisof NIT-1cell induced by palmitateModel group apoptosis rate is significantly higher than control group （P <0.01）,and that of intervention groups are lower than model group （P <0.01）. Among themSRCRR group is significantly lower than SRC, SRR and NS groups （P <0.01）Part2Effect of rat serum with rhizoma coptidis, radix rehmanniae on the GSISdysfunction of NIT-1cell induced by palmitate1. Insulin concentrations of model group is significantly lower than control group （P <0.01）, that of of every intervention group are significantly higher than model group（P <0.01）. Among them SRCRR group is significantly higher than SRC, SRR andNS groups （P <0.05）2. Ration of ATP/ADP in beta cells is significantly lower than control group （P <0.01）, and that of intervention group is significantly higher than model group （P <0.01）. Among them ATP/ADP of SRCRR group is significantly higher than SRRSRC group and NS group groups （P <0.05）.3. K+ATPion channels in model group is significantly higher than control group （P <0.01）, and that of intervention groups are significantly lower than the modelgroup （P <0.01）. Among them, K+ATPion channels current of SRCRR group issignificantly lower than SRR, SRC and NS groups （P <0.05）..4. Ca²⁺ion channels current in model group is significantly lower than control group（P <0.01）, and that of intervention group is significantly higher than model group （P <0.01）. Among them Ca²⁺ion channels current of SRCRR group issignificantly higher than SRR,SRC and NS group （P <0.01）.5. Calcium ion concentration in model group is significantly lower than control group（P <0.01）, and that of intervention groups are significantly higher than modelgroup （P <0.01）. Among them Ca²⁺concentration of SRCRR group issignificantly higher than SRR, SRC and NS groups （P <0.05）.Conclusion1. Rhizoma coptidis and radix rehmanniae can prevent cell apoptosis caused by PA in longterm. The effect of SRCRR is better than other drug groups except Repaglinide group2..Rhizoma coptidis and radix rehmanniae may adjust cell metabolism and causeATP/ADP to increase, leading to closure of K+ATPchannels resulting in beta cellsdepolarization. The depolarization causes voltage dependant Ca²⁺channels to opencausing Ca²⁺to flow into the cells, and triggering insulin secretion which can protectbeta cell GSIS function from damage. The effect of SRCRR is better than other druggroups except Repaglinide group.