Renal apoptosis after shockwave application in rabbit model

Purpose: To identify any apoptotic effect of shockwave lithotripsy (SWL) on renal tubular and glomerular cells. Materials and Methods: Thirty-five male New Zealand White rabbits were divided into five groups of seven rabbits each: I (control), II (sham), and III, IV, and GV (treated and sacrificed 1, 7, and 28 days after SWL, respectively). Intramuscular anesthetic agent (ketamine HCl; 20 mg/kg) and intravenous contrast medium (iohexol 300 mg of I/mL) were administered to animals in group II. The left kidneys of animals in groups III, IV, and V were exposed to 2000 shockwaves at 18 kV after administration of anesthesia and contrast medium. The animals were sacrificed on day 1, 7, or 28 after SWL, and the kidneys were removed. Apoptotic and proliferative indices of renal tubular and glomerular cells were determined by terminal deoxynucleotidyl transferase dUTP nick and label (TUNEL) and Ki-67 labeling methods, respectively, counting 1000 cells in each preparation. Results: No apoptosis was detected in glomerular cells in any group. The mean apoptotic indices of the tubular cells in animals in groups I and II were 483.0 +/- 85 and 484.4 +/- 105, respectively with no significant difference between the groups. In groups III and IV, the mean apoptotic indices were 343.4 +/- 89 and 358.4 +/- 61, respectively. There were no statistically significant differences between groups III and IV and the control group. Similarly, there were no significant differences in the apoptotic indices in groups III and IV. However, the apoptotic index in group V was 821.4 +/- 57, significantly higher than in the control group. The proliferative indices of all SWL groups were lower than that of the control group. Conclusion: Shockwave lithotripsy has an apoptotic effect on renal tubular cells that can be detected 4 weeks after the procedures, but no apoptotic effect on glomerular cells. Treatment with SWL also attenuates the proliferation of both tubular and glomerular cells.