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Rafael Roehrs Daniela R. J. Freitas Aoi Masuda João A. P. Henriques Temenouga N. Guecheva Ana-Ligia L. P. Ramos Jenifer Saffi 《Archives of microbiology》2010,192(3):221-228
Vitamin A (Vit A) is widely suggested to be protective against oxidative stress. However, different studies have been demonstrated
the pro-oxidant effects of retinoids in several experimental models. In this work, we used the yeast Saccharomyces cerevisiae as a model organism to study the Vit A effects on superoxide dismutase (SOD)-deficient yeast strains. We report here that
Vit A (10, 20 and 40 mg/ml) decreases the survival of exponentially growing yeast cells, especially in strains deficient in
CuZnSOD (sod1Δ) and CuZnSOD/MnSOD (sod1Δsod2Δ). We also observed the protective effect of vitamin E against the Vit A-induced toxicity. Possible adaptation effects induced
by sub-lethal oxidative stress were monitored by pre-, co- and post-treatment with the oxidative agent paraquat. The enzymatic
activities of catalase (CAT) and glutathione peroxidase (GPx), and the total glutathione content were determined after Vit
A treatment. Our results showed that CuZnSOD represents an important defence against Vit A-generated oxidative damage. In
SOD-deficient strains, the main defence against Vit A-produced reactive oxygen species (ROS) is GPx. However, the induction
of GPx activity is not sufficient to prevent the Vit A-induced cell death in these mutants in exponential phase growth. 相似文献
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M V Ivanov B A Lianda-Geller A D Morozova V S Pirogov G V Samsonov 《Prikladnaia biokhimiia i mikrobiologiia》1986,22(6):806-809
The effect of heat treatment used in the course of tuberculin production by Mycobacteria tuberculosis cells on the structure and biological activity of tuberculin was studied. Methods of preparative and analytical gel-filtration were used. The largest quantity of the biologically active component was obtained after 2-hour heat treatment of the mycobacteria culture. 相似文献
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S A Sakr 《Folia morphologica》1990,38(4):339-343
The preventive effect of vitamin A acid (13-cis-retinoic acid) on skin papillomas induced in rabbits (Oryctolagus cuniculus) by the bite of bed bugs (Cimex lectularius) pre-irradiated with gamma rays was investigated. Painting the papillomas with an oily 13-cis-retinoic acid suspension twice a week in a dose of 25 mg/kg body weight leads to significant regression of these structures. 相似文献
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