The Influence of Platelet-Derived Growth Factors on the Proliferation of Germinal Epithelium After Local Irradiation with Electrons.

Background: At present, the damage of male reproductive function caused by electron irradiation, as well as the development of methods for its correction are the relevant topics for further research. In fact, the effect of leukocyte-poor platelet-rich plasma (LP-PRP) growth factors are poorly investigated on different aspects of male fertility.

Methods: In this study, Wistar rats were divided into four groups; I) control which were injected with saline; II and III) groups (n=65) whose testes were locally irradiated with electrons to a dose of 2 Gy (linear accelerator "NOVAC-11"); III) the group (n=30) which received LP-PRP for 11 weeks after irradiation; and IV) animals (n=30) which received only LP-PRP (conditional control). The testes were studied by histological, immunohistochemical (IHC), western blotting, and TUNEL methods using Ki-67, Bcl-2, and p53. Comparison between groups was performed and p<0.01 was set as the level of significance.

Results: The results showed a decrease in the expression levels of Ki-67 and Bcl-2 besides an increase in p53-positive cells by the end of the experiment (p<0.01). After injection of LP-PRP, a gradual restoration of the proliferative activity of gametes was noted, which was confirmed by an increase in the proportion of Ki-67- and Bcl-2-positive germ cells (46.4±2.3, p<0.01 and 23.5±1.1, respectively, p<0.01).

Conclusion: Ki-67 expression and TUNEL analysis in the testes revealed a modulation of the proliferative-apoptotic balance towards apoptosis of germ cells after 2 Gy local electron irradiation. A tendency to restore the proliferative-apoptotic balance was noted after LP-PRP injections as indicated by increase in Ki-67-positive germ cells.