Investigation on the Effect of Low Intensity Ultrasound Stimulation on Mouse Spermatogonial Stem Cell Proliferation and Colonization

Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis. New procedure such as sound wave especially low intensity ultrasound (LIUS) can be effective on increasing the number of cells. In this study, the effect of LIUS stimulation on mouse SSCs proliferation and colonization was investigated. Isolated SSCs from neonatal mice were cultured in DMEM culture medium with 10% Fetal Bovine Serum (FBS). In the first phase of study, temperature controlled by LIUS of plate containing culture medium and in the next phase, SSCs stimulated by LIUS with 3 different Intensity doses (100, 200 and 300 mW/cm2) for 5 days and SSCs proliferation and colonization assessed at day 7. The LIUS treatment of mouse SSCs increased the proliferation and colonization of SSCs in experimental groups compared to the control group. The average of proliferation in 100, 200, 300 mW/cm2 and control group were 1.96 ± 0.03, 2.26 ± 0.03, 1.73 ± 0.03 and 1.66 ± 0.03, respectively. The average number of colonies in 100, 200,300 mW/cm2 and control group were 45 ± 1.2, 53 ± 2.4, 28 ± 1.2 and 20 ± 0.8, respectively. The average diameters of colonies in 100, 200, 300 mW/cm2 and control group were 235.3 ± 6.8 μm, 204.6 ± 12.3 μm, 203.6 ± 5.6 and 214.3 ± 9.1 μm, respectively. The results showed significant increase in proliferation rate and number of colonies in experimental groups compared to control group (P<0.05), whereas there were no significant difference between groups regarding to diameter of colonies. The results suggested that LIUS treatment can be an efficient and cost-effective method to improve the proliferation and colonization of SSCs during culture.