Radiation effect and neurochemical correlates of white and black rats

The aim of this work was to study the dependence of the individual radiosensitivity of white and black rats, which were cross-bred and named Ratus Ratus-Georgia. Comparative radiosensitivity of white Wistar rats and black rats was studied under general irradiation in sublethal doses (5, 7 and 9 Gy). Radiosensitivity was determined by the cumulative functions of servival, the spectrum of changes in a number of ethological parameters, the content of serotonin and catecholamines in various brain structures. After irradiation at doses of 5, 7 and 9 Gy, the regression coefficients of the dependence of the type of survival functions on the radiation dose in black rats are significantly higher than in white rats. The change in the mortality rate per unit change in the radiation dose depends on the synthesis of serotonin and on the number of sulfhydryl groups, the deficiency of which is one of the important factors for white rats. The data obtained suggest that after the irradiation of rats in sublethal doses, the change in radiosensitivity is caused not only by the consequences of radiation injury, but also by the activation of the serotoninergic system during restitution after radiation injury. On the other hand, the higher radiosensitivity of white rats compared to black rats is associated with a low content of serotonin, thiols, melanin, and some other biologically active substances, which are endogenous radioprotectors that determine individual radio-resistance. (author)