The effect of carnosine on the liver enzyme system in the irradiated body]

The effect of carnosine on post-radioactive changes in lipid peroxidation (LPO) products in blood serum and cytochrome P-450 content in liver microsomes has been studied. Per os administration of carnosine 24 hours prior to irradiation in a minimal lethal dose (7 Gr) markedly decreases the post-radioactive accumulation of LPO products in rat blood serum one hour after irradiation and fully restores the post-radioactive decrease in the cytochrome P-450 content in rat liver microsomes on day 5 after irradiation. Besides, the ability of carnosine to prevent the post-radioactive decline in the activity of UDP-glucuronyl transferase. Another key enzyme of the liver detoxifying system, has been demonstrated. The data obtained testify to the ability of carnosine to provide effective protection against post-radioactive intensification of LPO in irradiated organisms.     

Influence of body size on the electric current perception threshold]

Although the threshold for electric current perception is of great importance for safety considerations and safety regulations, important aspects remain unsolved, e.g. the role of age or body size. In the present study measurements of the perception threshold were performed in 790 persons aged between 18 and 82 years randomly selected from the general population. For the first time, the composition and size of the sample were selected such as to allow extrapolation to the general population. The results reveal not only statistically significant gender differences in the perception threshold but also statistically significant relationships between perception threshold and body size. The assumption that the differences in body size between men and women are responsible for the gender-specific difference in electric current perception threshold was not confirmed in this study.     

Effect of branched-chain amino acids on the irradiated body

The administration to rats of amino acids (valine, leucine, and isoleucine) for 10 days after whole-body X-irradiation with a dose of 7 Gy increased the survival rate and average life of animals and normalized some carbohydrate and nitrogen metabolism indexes. The insulin-like effect of these amino acids on glucose absorption by phrenic muscles of the exposed rats was detected.     

Interferon is the suppressor of hematopoiesis generated by stimulated lymphocytes in vitro

Lymphocytes that inhibit hematopoiesis may have a pathogenic role in some forms of bone marrow failure, and lymphocyte-mediated suppression may also be important in the normal regulation of bone marrow function. We have investigated the mechanism of in vitro suppression of hematopoiesis by T cells by using the methylcellulose colony culture system. Total peripheral blood T cells and separated subpopulations of helper (OKT4+) and suppressor (OKT8+) cells that have been stimulated by exposure to lectin suppress autologous colony formation by bone marrow myeloid (CFU-C) and erythroid (BFU-E) progenitor cells. Medium conditioned by these cells is also inhibitory, indicating that the suppressor activity is a soluble factor. A strong correlation existed for the concentration of interferon and the degree of hematopoietic suppressor activity in these supernatants; both activities peaked at days 3 to 5 of incubation and had sharply declined by day 7. Interferon production was enhanced by exposure of lymphocytes to sheep red blood cells during the rosetting procedure. Specific antiserum and a monoclonal antibody directed against gamma-(immune) interferon abrogated the inhibitory activity for hematopoiesis produced by lectin-stimulated T cells; an antiserum to alpha-interferon was generally much less effective in neutralizing activity. We infer from these results that gamma-interferon is the mediator of hematopoietic suppression generated by lectin-treated T-cells.     

Stimulation of the postradiation recovery of hematopoiesis in irradiated animals using a calf splenic extract

The injection of a purified cytoplasmic supernatant from calf splenocytes to lethally irradiated mice and hamsters favors the recovery of haemopoiesis and increases the survival rate. Proteins of 50--75 kDa molecular mass, having no specific features but being highly labile, are responsible for the radiobiological effect. The enzymic characteristics of the purified extract permit to suggest that the inhibitors of DNAase I and Ca2+, Mg2+-endonucleases are involved in the postirradiation transformations in the exposed animals.     

Influence of body position on the urinary output of adrenaline and noradrenaline]

In normal subjects in basal conditions, urinary excretion of noradrenaline is directly related to the hydrostatic pressure changes induced by the body posture in the dependant parts of the venous system. Adrenaline elimination is no influenced by these factors.