Platelet-rich plasma (PRP) influences tissue repair, stimulating the proliferation and differentiation of progenitor cells. The aim of the study was to evaluate the effect of vascular endothelial growth factor (VEGF) on spermatogenesis after 2 Gy electron irradiation. Materials and Methods. Light microscopy and immunohistochemical reactions with antibodies to VEGF were used to examine testes of 5 groups of experimental animals (Group 1 – control (n=10), Group 2 – 2IR (n=35), Group 3 – 2IR+LP-PRP+IGF-1 (n=30), Group 4 – 2IR+LP-PRP (n=30), Group 5 – LP-PRP (n=30)). Results. After irradiation, a decrease in the number of VEGF-positive cells was observed, which was restored under PRP administration. Conclusion. 2 Gy electron irradiation of the testes leads to a decrease in VEGF-positive cells. PRP administration, containing vascular endothelial growth factor, enhances reparative processes and restores spermatogenesis.

Previously, we showed that a nitric oxide synthase (NOS) inhibitor, compound T1023, induces transient hypoxia and prevents acute radiation syndrome (ARS) in mice. Significant efficacy (according to various tests, dose modifying factor (DMF)—1.6–1.9 against H-ARS/G-ARS) and safety in radioprotective doses (1/5–1/4 LD10) became the reason for testing its ability to prevent complications of tumor radiation therapy (RT). Research methods included studying T1023 effects on skin acute radiation reactions (RSR) in rats and mice without tumors and in tumor-bearing animals. The effects were evaluated using clinical, morphological and histological techniques as well as RTOG classification. T1023 administration prior to irradiation significantly limited the severity of acute RSR. This was due to a decrease in radiation alteration of the skin and underlying tissues, and the preservation of the functional activity of cell populations that are critical in the pathogenesis of radiation burn. The DMF values for T1023 for skin protection were 1.4–1.7. Moreover, its radioprotective effect was fully selective to normal tissues in RT models of solid tumors—T1023 reduced the severity of acute RSR and did not modify the antitumor effects of γ-radiation. The results indicate that T1023 can selectively protect the non-malignant tissues against γ-radiation due to hypoxic mechanism of action and potentiate opportunities of NOS inhibitors in RT complications prevention.