Promene steroidnih receptora u toku histopatoloske transformacije tkiva humanog uterusa

Estrogen (ER) and progesterone receptors (PR) were analyzed in the cytosol and nuclei prepared from specimens of human uterine tissue of patients with certain disorders identified as hyperplasia endometrii adenomatosa, myoma uteri per magnum, adenocarcinoma endometrii and adenocarcinoma corporis uteri. These investigations have revealed a different level of ER and PR in analyzed tissue specimens, as well as the existence of a relationship between changes in receptor levels and respective Kd. These changes suggest a correlation between steroid receptor levels and the type of tissue transformation. The functionality of the receptors was analyzed by the ultracentrifugation of non-activated and activated steroid-receptor complexes in sucrose density gradients, as well as by the investigation of their interaction with isolated nuclei. These results indicate that some changes in steroid receptor molecules can be detected when the tissue turns from normal to malignant transformation. On the basis of this investigation it could be proposed that the analysis of activated and non-activated steroid-receptor complexes by means of the methods used in this study can be applied as a useful clinical tool in the determination of the endocrine dependence of transformed tissues, as well as for the optimum dosing of individual treatment of patients with uterine and other tissue carcinoma

Regional differences in antioxidative response of rat brain after cranial irradiation

In order to examine if differences in activity and inducibility of antioxidative enzymes in rat cerebral cortex and hippocampus are underlying their different sensitivity to radiation, we exposed four-day-old female Wistar rats to cranial radiation of 3 Gy of γ-rays. After isolation of hippocampus and cortex 1 h or 24 h following exposure, activities of copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT) were measured and compared to unirradiated controls. MnSOD protein levels were determined by SDS-PAGE electrophoresis and Western blot analysis. Our results showed that CuZnSOD activity in hippocampus and cortex was significantly decreased 1 h and 24 h after irradiation with 3 Gy of γ-rays. MnSOD activity in both brain regions was also decreased 1 h after irradiation. 24 h following exposure, manganese SOD activity in hippocampus almost achieved control values, while in cortex it significantly exceeded the activity of the relevant controls. CAT activity in hippocampus and cortex remained stable 1 h, as well as 24 h after irradiation with 3 Gy of γ-rays. MnSOD protein level in hippocampus and cortex decreased 1 h after irradiation with 3 Gy of γ-rays. 24 h after exposure, MnSOD protein level in cortex was similar to control values, while in hippocampus it was still significantly decreased. We have concluded that regional differences in MnSOD radioinducibility are regulated at the level of protein synthesis, and that they represent one of the main reasons for region-specific radiosensitivity of the brain