Establishment Of Renal Calculus Rat Model Induced By Calcium Nanoparticles And The Preliminary Study Of Its Mechanism

Objective:Establishment of renal calculus rat model induced by calcium nanoparticles.In the process of establishment of renal calculus rat model induced by calcifying nanoparticles,the contents of neutrophil gelatinase associated lipocalin(NGAL),osteopontin(OPN),monocyte chemoattractant protein-1(MCP-1)in rat urinein different time periods were detected to analyse the formation mechanism of kidney stones induced by CNPs.Those provide new ways of the treatment and prevention of recurrence of patients suffering from kidney stone.Methods:Calcifying nanoparticles were extracted and cultivated from clinically diagnosed patients with nephrolithiasis.40 adult male SD rats were randomized into 4 groups(n=10 each): group A1,A2,A3,given an intravenous injection of calcifying nanoparticles;group B,given an intravenous injection of 0.9%NS.Urine of rats was collected by using metabolic cages in different time periods after injection of CNPs.The contents of NGAL,OPN and MCP-1 in rat urine in different time periods were detected using ELISA method.Rats were sacrificed in different time periods.The kidneys were examined for pathology.Results: At the eighth week,histopathological studies of the renal tissue of group A after Von Kossa staining and nuclear fast red staining showed irregular distribution of dark brown or brown calcium crystallization,mainly distributed in the proximal tubule and distal convoluted tubule.Therefore,the establishment of renal calculus rat model induced byCNPs was successfully established.The concentration of NGAL in groupA(1913.46 ? 223.23ng/L)were higher than that in group B(1583.54 ? 57.49ng/L)at the fourth hour after the injection(P<0.05);the concentration of OPN(28.00 ? 2.69?g/L)and MCP-1(573.78 ? 50.22ng/L)in group A began to increase largely compared with the concentration of OPN(16.40 ? 1.54?g/L)and MCP-1(525.92 ? 29.95ng/L)in group B at the second week after the injection(P<0.05);the concentration of NGAL(3978.85 ? 810.81ng/L)and OPN(33.35 ? 10.93?g/L)and MCP-1(734.07 ? 201.47ng/L)in group A multiplied more significantly compared with the concentration of NGAL(1642.58 ? 109.75ng/L)and OPN(18.56 ? 2.93?g/L)and MCP-1(534.81 ? 51.14ng/L)in group B at the eighth week after the injection(P<0.05).At the first week,histopathological studies of the renal tissue of group A showed a small amount of renal tubular epithelial cells granular degeneration,and no renal tubular crystallization.At the second week,histopathological studies revealed small quantities of calcium crystallization in the renal tubules,accompanied with vacuolar degeneration and granular degeneration of a few renal tubular epithelial cells.After two weeks,the deposition of calcium crystals in the renal tubules was positively related to the level of NGAL,OPN and MCP-1.At the eighth week,histopathological studies revealed a large number of calcium crystallization in the renal tubules,accompanied with extensive vacuolar degeneration of renal tubular epithelial cells.No calcium crystals deposition and no pathological changes could be seen in the renal tissue of group B.Conclusion:The CNPs extracted from humam beings who were diagnosed with nephrolithiasis could result in rats suffering from kidney stones.Calcifying nanoparticles began to injure renal tubular epithelial cells at the fourth hour after the injection.The adhesion and aggregation of calcium crystals began to appear in the renal tubules at the second week after the injection,and the crystals multiplied more and more with the severity of injury.The increasing number of calcium crystals can stimulate more expression of MCP-1 in renal tubular epithelial cells.Mononuclear macrophage and OPN were involved in the adhesion and aggregation process.