Effect of low energy shock wave on testicular microenvironment homeostasis in rats

Abstract

Objective: To further investigate whether two sets of low-energy extracorporeal shock waves (LESWs) impulse parameters, i.e., 0.02 mJ/mm2 for 500 impulses and 0.04 mJ/mm2 for 500 impulses, which have been shown to directly affect the testes, can promote testicular spermatogenesis or positively regulate homeostasis of the testicular microenvironment. Methods: (1) Twenty-four experimental rats were randomly divided into a 0.02 mJ/mm2 500 impulses group (L1 group), a 0.04 mJ/mm2 500 impulses group (M1 group), a sham intervention group (S group) and a blank control group (N group). The experiment period was 8 weeks. (2) Apoptosis of the spermatogenic cells in the left testicle was detected by the TUNEL method, VEGF and eNOs protein expression was detected by immunohistochemistry, and histomorphological changes were observed in PAS-stained sections. Moreover, the morphologies of the spermatogenic tubules and testicular stroma were quantitatively analyzed by stereological analysis. The right testicle was used for Western blot detection of the protein expression levels of Bax, Cytochrome C, Caspase-3, Bcl-2, VEGF and eNOs. Results: Compared with the other three groups, the rate of M1 testicular germ cell apoptosis induced by shock treatment was higher, the expression levels of proapoptotic proteins increased significantly while that of the antiapoptotic protein was lower, and the suppression of cell proliferation correlated with the protein expression levels. Additionally, with respect to the absolute volume of the seminiferous tubules, the absolute interstitial testicular volume notably increased, producing a series of biological effects working against testicular sperm production and function. However, there was no significant difference between the L1 group and the N and S groups. Conclusions: LESWs treatment with impulse parameters of 0.02 mJ/mm2 for 500 impulses showed a better protective effect on testicular spermatic function in rats and has a positive regulatory biological effect.

Keywords

• Low energy shock waves
• Apoptosis
• Proliferation
• Microenvironment
• Testes