[The effect of ionizing radiation on the nervous mechanisms regulating cardiac activity]. / Vplyv ionizuiuchoï radiatsiï na nervovi mekhanizmy rehuliatsiï diial'nist' sertsia.

Functional state of cardiac nervous links and pattern of cardiogenic reflectory responses to radiation (4 Gy) were studied in acute experiments on anesthetized rats at various periods after single radiation. The control level of nervous activity significantly varies in different terms after radiation. Intensification of parasympathetic effects and domination of depressor reactions are typical of the initial period (the 1st day). A decrease in the sympathetic tone and weakening of adrenergic influences are observed in all terms after radiation (from the 1st till the 14th day). Interrelationships between sympathetic and parasympathetic links of heart regulation as well as cardiogenic reflectory responses are not restored to the control level in remote terms after radiation (the 14th-20th days). So, single radiation of animals in a dose of 4 Gy has induced a disorder in the nervous heart regulation, which may be a cause of different pathological states.