ABSTRACT
Stress such as exposure to ionizing radiation is able to activate the hypothalamus-pituitary-adrenal axis. The present study sought to examine the effects of different configurations of a 10-Gy gamma irradiation in rats on the hypothalamus-pituitary-adrenal axis to understand the mechanism of negative feedback by glucocorticoids induced by ionizing radiation. Specifically, we determined adrenocorticotropin and corticosterone levels in plasma as well as corticotrophin-releasing factor expression in the paraventricular nucleus of the hypothalamus by in situ hybridization from 6 h to 4 days after total-body, abdominal or head irradiation. In this study, we found an activation of the hypothalamus-pituitary-adrenal axis after radiation exposure. Plasma adrenocorticotropin and corticosterone levels were significantly increased after total-body and abdominal irradiation 3 days after exposure, in parallel with decreased labeling of corticotrophin-releasing factor mRNA in the parvocellular region of the paraventricular nucleus of the hypothalamus. Our results suggest that ionizing radiation activates the neuroendocrine system to protect the organism from the occurrence of radiation-induced inflammation.
Subject(s)
Adrenocorticotropic Hormone/blood , Corticosterone/blood , Corticotropin-Releasing Hormone/metabolism , Hypothalamo-Hypophyseal System/metabolism , Hypothalamo-Hypophyseal System/radiation effects , Pituitary-Adrenal System/metabolism , Pituitary-Adrenal System/radiation effects , Adaptation, Physiological/radiation effects , Adrenal Glands/cytology , Adrenal Glands/metabolism , Adrenal Glands/radiation effects , Animals , Dose-Response Relationship, Radiation , Gamma Rays , Hypothalamo-Hypophyseal System/cytology , Hypothalamus/cytology , Hypothalamus/metabolism , Hypothalamus/radiation effects , Male , Organ Size/radiation effects , Organ Specificity/radiation effects , Pituitary Gland/cytology , Pituitary Gland/metabolism , Pituitary Gland/radiation effects , Pituitary-Adrenal System/cytology , Radiation Dosage , Rats , Rats, Wistar , Time Factors , Whole-Body Irradiation/methodsSubject(s)
Calcium/therapeutic use , Hyperlipidemias/therapy , Magnesium/therapeutic use , Mineral Waters , Adult , Female , Humans , Hyperlipidemias/blood , Hypolipidemic Agents , Lipids/blood , Male , Middle AgedABSTRACT
Results of 5-year periodic examinations and SDH, LAP and GGTP activity in blood serum of 207 workers chronically exposed to ethyl gasoline and other petroleum products were analysed. In addition, in the selected groups, the levels of IgA, IgG and IgM immunoglobulins, complement C3 fraction and alpha2 macroglobulins were determined. Results of objective and enzymatic examinations indicate a slight toxic liver lesion. No significant changes in albuminous fractions were found, except a significant reduction in alpha2 macroglobulins.