Levels of catecholamines in the hypothalamus, hypophysis and in the adrenal in sheep after whole-body exposure to gamma rays

The changes were studied in the levels of catecholamines and L-DOPA in the control system of reproduction cycle (hypothalamus, hypophysis) and in adrenal glands of sheep after all-body irradiation with 60Co at the total dose of 6.7 Gy for seven days. The power input per hour of irradiation source was 0.039 Gy. The catecholamines (noradrenaline, dopamine and adrenaline) and L-DOPA were determined, after having been isolated from the tissues, by the method of spectral fluorimetry. After all-body exposition to gamma-radiation noradrenaline dropped in hypothalamus in comparison with the control group of sheep, most significantly in the rostral (by 74.2%) and caudal part (by 40%). A similar drop like in the case of noradrenaline was also observed in dopamine, the concentrations of which decreased in rostral hypothalamus by 72%, in medial hypothalamus by 94% and in caudal hypothalamus by 60%. Adrenaline shows a drop in hypothalamus, most significant in caudal region (by 62%). In relation with that the level of a precursor for the synthesis of catecholamines and L-DOPA has been changed which achieved, in the studied regions of hypothalamus in sheep, significantly lower levels than were determined in the control group of sheep. As regards the hypophysis, after irradiation no significant changes in the levels of noradrenaline and adrenaline were recorded, however, dopamine and L-DOPA dropped significantly (P less than 0.01). The exposition to gamma-radiation also causes a decrease in the concentrations of catecholamines and L-DOPA in the adrenal glands of sheep, most significant in noradrenaline (by 61%).(ABSTRACT TRUNCATED AT 250 WORDS)