Effects of repeated extracorporeal shock wave on kidney apoptosis of normal and diabetic rat

To assess the effect of repeated extracorporeal shock waves (ESW) on the apoptosis of renal parenchyma in normal and diabetic rats by the caspase-3 expression.

80 rats were assigned for ESW (Direx Tripter X1(R) - 14 KVA) to one of three groups with 50% rats with diabetes (A) and 50% normal (B) in each: G1 (n = 40): no ESW; G2 (n = 20): one ESW; G3 (n = 20): two ESWin an interval of 14 days. The animals were sacrificed 3 days after the ESW and samples of the renal parenchyma were histologically prepared, stained by the caspase-3 cleavage immunohistochemical method, and the apoptotic index (ApIn) was calculated by computer program Image Pro-Plus V 4,5,1 Media Cybernetics ( ApIn = number of apoptotic cells in the microscopic section / total cells in the microscopic section).

There was no statistical difference in ApIn of normal rats with one ESW (8.4 +/- 0.2) or two ESW (9.1 +/- 0.3) and both were similar to the control group with no ESW (7.9 +/- 0.2). The ApIn of diabetic rats with one ESW (7.4 +/- 0.3) was similar to the normal rats with one or two ESW. On the other hand, the ApIn was statistically higher in diabetic rats with two ESW (11.9 +/- 0.4) than in diabetic rats with one ESW (7.4 +/- 0.3).

The ApIn of normal rats with a single (2,000 SW) or repeated ESW (4,000 SW) was similar to the control animals without any ESW. In diabetic rats, the repeated ESW (4,000 SW) may result in an additional risk of tissue damage expressed by the higher ApIn.