Experimental Study On The Relationship Between The Rate Of Calculus Formation And Oxidative Stress In A Modified Drosophila Calcium Oxalate Kidney Stone Model

Objective:To observe the correlation between the formation rate of calcium oxalate stone and oxidative stress in a modified drosophila calcium oxalate kidney stone model.Methods:The drosophila was divided into 3 groups:blank control group(fed on standard medium from the egg stage),conventional model group(fed with medium containing 0.5%ethylene glycol from the adult stage)and modified model group(fed with medium containing 0.5%ethylene glycol from the egg stage).The malpighian tube was dissected and the rate of stone formation in each group was observed by a polarizing microscope every day-age.The stone composition was identified by FT-Raman spectroscopy,and the lifespan of each group was observed.The enzyme activity assay method was used to detect the expression of malondialdehyde(MDA),catalase(CAT)and superoxide dismutase(SOD)at instar larvae 3rd day and adults 0,4th,10th,14th day in each three groups.Results:1,The stone formation was completed and the rate achieved 100%at 14th day and 22th day of adult age in modified model group and conventional model group,respectively.A further compare indicated the ratio of "++"～"+++" in the conventional group and the improved model group were 39%±4.16%and 40.5%±4.43%,respectively(P>0.05).The median survival times were 30.5 days and 30 days respectively in the conventional group and the improved model group(P>0.05).2,The results of enzyme activity assay showed the SOD level in the malpighian tube in conventional model group was lower than the blank control group at adult 4th,10th and 14th days(P<0.01),but the MDA levels in the malpighian tube was higher than the blank control group,additionally,the CAT levels was lower than the blank control group at adult 10th and 14th days(P<0.01).The levels of SOD and CAT in improved model were lower and the MDA levels was higher than the blank control group at 3rd instar larvae,adult 0,4th,10th and 14th day(P<0.01).The SOD levels in modified model group were lower than the conventional model at adult 0,4th,10th and 14th day(P<0.05).And the CAT level in improved model were lower than the conventional model at adult 0,4th and 10th day(P<0.05).The levels of MDA of the malpighian tube in modified model were higher than the conventional model at 3rd instar larvae and adult 0,4th,10th and 14th day(P<0.05).Conclusion:1,The modified calcium oxalate nephrolithiasis model is safe and feasible.Its advantages lie in shortening the model construction time and improving the efficiency of the model establishment.2,The formation of calcium oxalate nephrolithiasis in Drosophila is related to oxidative stress,and the oxidative stress reaction positively correlates with the increase of the stone formation rate.