[Physiological characteristics of posture maintenance by dogs during immediate reaction to irradiation].

The ability of dogs to maintain a vertical posture during the first hours after irradiation at a dose of 10 or 80 Gy was investigated. Two experiments were performed. In the first experiment, during 5 hours after irradiation the vector stabilogram area, peak muscle efforts and sensorimotor coordination were measured 10 times every 30 min. In the second experiment, postural responses to perturbations were measured before and after irradiation at a dose of 10 Gy. During exposure to 10 Gy maximum values of the vector stabilogram area reflected initial excitation and motor unrest, that preceded vomiting, while minimum values of the parameter were related to hypodynamia during 3-5 hours after exposure. During exposure to 80 Gy minimum values of the vector stabilogram area reflected the hypodynamic phase while maximum values were related to the phase of distinct cerebral lesions. A reliable indicator of the quality of vertical posture maintenance, that correlates with the post-irradiation quality of purposeful actions, including intermittent physical acts, or actions, requiring highly precise coordination, is the rate of posture recovery after instantaneous platform displacement. This parameter declined after irradiation, the maximum decrease being during the 4-5th hour.