[The epididymal adipose tissue of mice after nanosecond pulse-periodic microwave irradiation].

The effect of pulse-periodic microwave radiation (PPMR) of the pulse repetition frequency of 8-25 pulseper second, the peak power density of 1500 W/cm2 on the epididymal adipose tissue of micewas investigated. The effect was assessed by the changes in the fat mass and size of the irradiated adipocytes. It was found that the fat mass and size distribution of adipocytes are affected by irradiation. The effects depend on the pulse repetition frequency and intensity of exposure.

[The antioxidant enzyme activity in mouse liver mitochondria after nanosecond pulsed periodic X-ray exposure].

The effect of repetitive pulsed X-ray (4 ns pulse duration, 300 kV accelerating voltage; 2.5 kA electron beam current) on the antioxidant enzyme activity in mouse liver mitochondria has been investigated. The mitochondrial suspension was exposed to single 4000 pulse X-ray radiation with repetition rates ranging between 10 and 22 pps (pulsed dose was 0.3-1.8 x 10(-6) Gy/pulse, the total absorbed dose following a single exposure was 7.2 x 10(-3) Gy). It was shown that a short-time exposure to X-ray radiation changes the antioxidant enzyme activity in mouse liver mitochondria. The greatest effect was observed in the changes of the activity of the metal-containing enzymes: superoxide dismutase and glutathione peroxidase. The effect depends on the pulse repetition frequency and radiation dose.

[DNA double-strand breaks in human lymphocytes after single irradiation by low doses of pulsed X-rays: non-linear dose-response relationship].

Effects of ionizing radiation registered in cells after low dose irradiation are still poorly understood. A pulsed mode of irradiation is even more problematic in terms of predicting the radiation-induced response in cells. Thus, the aim of this paper was to study and analyze the effects of dose and frequency of pulsed X-rays on the frequency of radiation-induced DNA double-strand breaks and their repair kinetics in human peripheral blood lymphocytes in vitro. Analysis of radiation-induced gammaH2AX and 53BP1 repair foci was used to assess the DNA damage in these cells. The dose-response curve of radiation-induced foci of both proteins has shown deviations from linearity to a higher effect in the 12-32 mGy dose range and a lower effect at 72 mGy. The dose-response curve was linear at doses higher than 100 mGy. The number of radiation-induced gammaH2AX and 53BP1 foci depended on the frequency of X-ray pulses: the highest effect was registered at 13 pulses per second. Moreover, slower repair kinetics was observed for those foci induced by very low doses with a nonlinear dose-response relationship.