Uric acid mediates photodynamic inactivation of caprine alpha-2-macroglobulin.

Uric acid (2,6,8 trioxopurine), the end product of purine metabolism in mammalian systems, has shown a wide range of antioxidant properties including scavenging of hydroxyl radical and singlet oxygen. In this study we show that in the presence of visible light, uric acid disrupted caprine alpha-2-macroglobulin (alpha(2) M) structure and antiproteolytic function in vitro. Proteinase cleaves the bait region of caprine inhibitor inducing major conformational changes and entrapping the enzyme within its molecular cage. In contrast to native alpha(2) M, modified antiproteinase lost half of its antiproteolytic potential within 4 hours of uric acid exposure. The changes in uv-absorption spectra of the treated protein suggested possible spatial rearrangement of subunits or conformational change. Analysis of the mechanism by which alpha(2) M was inactivated revealed that the process was dependent on generation of superoxide anion and hydrogen peroxide. Our findings suggest that antiproteolytic activity of caprine alpha(2) M could be compromised via oxidative modification mediated by uric acid. Moreover, low concentrations of alpha(2) M were found to stimulate superoxide production by some unknown mechanism.

[The joint action of nitrates and gamma radiation on the blood plasma proteinase-inhibiting and antioxidative systems in rats]. / Sochetannoe vozdeistvie nitratov i gamma-izlucheniia na proteinazoingibitornuiu i antiokislitel'nuiu sistemy plazmy krovi krys.

The separate and combine influence of nitrates (40 mg of natrium nitrate) 100 g of body mass during 60 days) and gamma radiation (3 Gy) on condition of proteolytic and antioxidative blood plasma systems of rats have been investigated. There are were increase of total proteolytic activity (TPA) on 3-day, adaptive increase of alpha-antiproteinase inhibitor (API) on 7- and 14-day after factors separate action and tendency to increase TPA together with the invariable content of API after combine influence. The decrease of alpha-2-macroglobulin level on 14-day after all influences and more significantly after combination of factors action have been also shown. The decrease of antioxidant system and system of free radicals inactivation have been observed.

Development of a competitive enzyme linked immunosorbent assay to measure alpha 2-macroglobulin in irradiated rat serum.

A competitive enzyme linked immunosorbent assay with antigen immobilized on the solid phase was developed to measure alpha 2-macroglobulin in rat serum. The cross reactivity with albumin and hemoglobin was eliminated by use of IgG fractions that were isolated after chromatography on Cibacron Blue F3-GA Sepharose immobilized rat whole serum and hemoglobin Sepharose. Blocking materials and pH of the coating buffer had no effect on the amount of alpha 2-macroglobulin that binds to the plate. When the coating amount of alpha 2-macroglobulin was 100 ng/well, at pH 7.4, 10 mM Tris-HCl containing 150 mM sodium chloride and the IgG amount added was 60 ng/well, then albumin and hemoglobin did not affect the assay at concentrations of 150 micrograms/ml or 200 micrograms/ml. This assay is useful for measuring the concentration of alpha 2-macroglobulin in normal and irradiated rat serum.

[A comparative analysis of the results of using different methods of helium-neon laser therapy in patients with stable stenocardia]. / Porivnial'nyi analiz rezul'tativ vykorystannia riznykh sposobiv heliievo-neonovoï lazeroterapiï u khvorykh na stabil'nu stenokardiiu.

Based on the findings from the examination of 133 patients with stable angina pectoris, it was shown that He-Ne laser therapy with the irradiation being applied to the liver projection area in combination with the prolonged-action nitrates is superior to similar application of irradiation to the precordial region and Head's zones or intravenous irradiation of blood. Revealed in the examination of the above patients was a reaction of antiproteolytic enzymes to He-Ne laser therapy, which appeared to be varying with methods of laser therapy. It is suggested that a reaction of the realization of the components of proteolysis might be involved in the realization of therapeutic effect of the He-Ne laser energy in patients with ischemic heart disease.

[Proteinase inhibitors of the blood plasma in the early period of the development of acute radiation sickness in monkeys]. / Ingibitory proteinaz plazmy krovi v rannii period razvitiia ostroi luchevoi bolezni u obez'ian.

A study was made of the postirradiation kinetics of blood antiproteinase activity in monkeys (Macaca nemestrina). Whole-body uniform gamma-irradiation (LD100/45) was shown to induce a significant decrease in the activity of alpha 2-macroglobulin during the first 24 h following irradiation: the decreased activity level was retained throughout the entire latent period of radiation sickness. At the height of radiation sickness (the 7th-10th day) up to the animals' death, a sharp increase was registered in the activity of alpha 1-inhibitor of blood plasma proteinases. The authors discuss a pathogenetic role of the diminution of the inhibitory potential of blood in the course of radiation sickness.

Effect of magnitude of daily continuous radiation dose on serum proteins and survival in rats.

Changes in serum prealbumin, A1-macroglobulin, transferrin, and complement levels were studied in rats irradiated with daily doses of 100R (0.0258 C/kg), 200R (0.0516 C/kg) and 400R (0.1032 C/kg) until death. The daily dose of 100R applied for 39 days produced no changes in prealbumin and transferrin and a rise in the levels of A1-macroglobulin and complement. Shortly before death, i.e., between 39 and 44 days of irradiation, the levels of all four patients dropped. Daily doses of 200 and 400R caused a reduction in the levels of all four proteins since the very beginning. The LD 50 was 4 270R (1.1017 C/kg) at 100R/day, 4 060 R (1.0475 C/kg) at 200R/day, and 4 520 R (1.1342 C/kg) at 400R/day.

The values of alpha 2-macroglobulin in the serum of persons at work with x-rays.

A group of 86 persons (65 women, 21 men) working at the risk of ionizing radiation (IR) was examined for the levels of alpha 2-macroglobulin (alpha2-M), and compared to a group of age matched healthy population. Whereas the difference in men did not reach a level of significance, significant difference was assessed in women: in a subgroup older than 40 y exposed to the IR a rise of alpha 2-M levels was noted in correlation with the age. Multiple correlation coefficients showed a synergistic influence of both age and exposure to IR. The results are discussed from the point of view of the hypothesis that in exposed women a shifting realizes of usual old age changes to younger age group. A possibility is suggested to use the examination of alpha 2-M levels for preventive control of workers at the risk of IR.