Damage Of Peritubular Capillaries And Renal Tubules In Contrast Induced Acute Kidney Injury

Objective:To study the relationship between peritubular capillaries and renal tubular injury during the occurrence and development of contrast induced acute kidney injury.Methods:48 SD rats weighing 250-300 g were randomly divided into experimental group and control group.The experimental group was dehydrated for 48 hours,and 30 minutes after intramuscular injection of furosemide injection(10m L/kg),iohexol injection(15m L/kg)was injected into the femoral vein.Blood samples were collected at 5 minutes,10 minutes,15 minutes,1 hour,24 hours,48 hours and 72 hours after contrast medium injection and the kidneys were taken out to make paraffin sections.In the control group,rats were dehydrated for 48 hours,and normal saline(10m L/kg)was injected intramuscularly for 30 minutes,then normal saline(15m L/kg)was injected into the femoral vein.Blood was collected from the vein,and the kidneys were taken out to make paraffin sections.Blood samples were collected from jugular vein in both experimental group and control group before operation.Serum creatinine concentration was measured by enzyme linked immunosorbent assay(ELISA)in both the experimental group and the control group.Renal tubular injury was evaluated by HE staining in renal paraffin sections,peritubular capillary dialatation was observed by PAS staining and the expression of intercellular cell adhesion mlecule-1 was detected by immunohistochemical staining.Results:Compared with the control group,the concentration of serum creatinine in the experimental group at 5min,24 h and 48 h after operation was significantly higher than that before operation(P<0.05).The scores of renal tubular injury in the experimental group at 5min,24 h and 48 h were significantly higher than those in the control group and the renal tubular injury was the most serious in the 5min group,followed by 24 h and48 h(P<0.05).Compared with the control group,the positive expression of intercellular cell adhesion molecule-1 in 5min in the experimental group was significantly higher than that in the control group(P < 0.05).PAS staining showed peritubular telangiectasia at 5min in the experimental group.Conclusion:Severe renal tubular injury and peritubular capillary injury occur in the early stage of contrast induced acute kidney injury.The disease may be the result of the interaction of two kinds of structural damage.