Ultrastructural changes of hypothalamic endocrine zones after irradiation with high energy carbon ions, neutrons, and gamma-rays*.

Ultrastructural lesions in the cells of hypothalamicendocrine zones of the rat brain were investigated 2 and 5 weeks after the exposure to accelerated carbon ions (E = 300 MeV/nucleon) and gamma-rays at a dose of 1.0 Gy and 11 weeks following irradiation with fast neutrons (1.5 MeV) at the doses of 0.25 and 1.0 Gy. The development of degenerative changes in cells of the rat's median eminence and arcuate nucleus after relatively low doses of carbon ions and neutrons was demonstrated. These changes in the hypothalamic endocrine structures could be the reason of the hormonal homeostasis disturbance.