Impact peculiarities of long-term gamma-irradiation with low-dose rate on the development of laboratory rats and their sperm production.

OBJECTIVE: To study the influence of long-term gamma-irradiation with low dose rate (13×10-6 cGy/s) on the body, testes and ventral prostate, development of laboratory rats, as well as quantitative parameters of sperm production along with kinetic characteristics of spermatozoa.

MATERIALS AND METHODS: The experiments were performed on laboratory white rats of 2,5 months in age. Animals were irradiated in gamma-field of "Ethalon" device in a dose range 0.1-1.0 Gy. Testicles, epididymises, ventral prostate were retrieved from decapitated animal, each organ weight being determined for every exposure dose. Sperm quantities in testicles and epididymises were identified with aid of phase-contrast microscopy after tissue homogenization in saline containing Troton X-100 and NaN3. Kinetic characteristics of spermatozoa were analyzed by video recording at 37 ºC.

RESULTS: The long-term gamma-irradiation with low dose rate was shown to cause no effect on the dynamics of animal weight and weight of epididymis changes. However the testes weight was noticed to diminish at doses 0.1, 0.3, 0.6 and 1.0 Gy, the latter dose being stimulative for the ventral prostate growth and weight accumulation. Total sperm quantities in testicles and epididymices along with daily sperm production declined in gamma-irradiated rats compared to control. However curvilinear and straight line spermatozoid velocity as well as the frequency of tail oscillations tended to increase.

CONCLUSIONS: Long-term gamma-irradiation of rat whole body with low dose rate just insignificantly affects the development of testes and ventral prostate. Apart from this, radiation effects showed up in sperm production slight suppression, from the on hand, and sperm velocity along with tail oscillations intensification, from the other hand.