Effect of chronic gamma-irradiation and beta-carotene on lipid metabolism in presynaptic membranes in rat brain.

Lysophosphatidylcholine is involved in radiation-induced modulation of presynaptic membranes in rat brain. High sensitivity of the cortical integrative functions to chronic low-dose gamma-irradiation is demonstrated. beta-Carotene produced a protective effect during chronic irradiation.

[The effect of beta-carotene on the cytoplasmic membrane lipids of cells in rats under chronic gamma irradiation].

Chronic gamma irradiation of rats at a dose rate of 12.9 rad/day for 155 days (total dose 20 Gy) did not change the cholesterol level in the brush border membrane of the small intestine. Maintenance of rats on a beta-carotene-enriched diet (daily throughout the irradiation period, at a diurnal dose of 3 mg/kg body weight produced an increase in cholesterol levels in the small intestinal brush border membranes.

[Medical-biological aspects of carotenoids].

The literature data involving 45 references are reviewed. Metabolism of carotenoids in human and animal tissues, distribution in tissues, antioxidative and immunomodulating activities of carotenoids, their anticarcinogenic properties are discussed. Use of remedial drugs containing beta-carotene holds much promise.

[Modification of the body's resistance to acute ionizing radiation by synthetic beta-carotene].

Radiomodifying efficiency of short-term and chronic medicinal and treatment-prophylactic enrichment of rations with artificial beta-carotene, administered at single doses of 0.1-10.0 mg, were studied after acute external gamma-irradiation of adult nonlinear and Wistar rats (0.

[Immunopharmacokinetics of synthetic beta-carotene].

The immunopharmacology and pharmacokinetics of synthetic beta-carotene were studied in complex clinico-laboratory investigations after single and repeated per os administrations of various doses of the drug to healthy volunteers and cancer patients. Repeated treatment with beta-carotene at a dose of 30 mg caused no significant changes in the immunological parameters studied. However, treatment with a dose of 250 mg altered the parameters as follows: alteration of beta-carotene content in blood, elevation of the counts of lymphocytes and T lymphocytes forming "active" rosettes, increase in the proliferative response of lymphocytes to the mitogen PWM and activation of natural killers.

[Preventive effect of domestic, synthetic beta-carotene on the development of rat mammary tumors induced by DMBA].

Preventive effects of artificial beta-carotene on the development of rat mammary gland adenocarcinomas induced by DMBA were studied in rats maintained on a diet containing beta-carotene at a dose of 2.5 mg per animal within 10 weeks, which was initiated after the carcinogen administration. The carotenoid treatment course caused the following effects: manifestation of adenocarcinomas induced by DMBA was decreased, latent period of neoplasm development as well as the rate of tumor differentiation were increased and metastatic spreading into the regional lymph nodes was inhibited.

[Inhibiting effect of domestic, synthetic beta-carotene and ascorbic acid on endogenous carcinogenesis in mice].

Carcinogenesis in mice induced by the tryptophane derivative 3-hydroxyanthranilic acid was studied after administration of synthetic beta-carotene and ascorbic acid. The incidence of induced hemoblastoses and hepatomas was decreased 2-fold, while the latent period of their development was, increased in mice on a lifetime feed containing 15 mg/kg of beta-carotene. The anticarcinogenic effect of ascorbic acid added to drinking water was similar to that of beta-carotene.

[Anti-necrosogenic action of natural and synthetic antioxidants in coronary occlusive myocardial infarct].

The synthetic liposoluble antioxidant BAT. 120 mg/kg, was found to produce markedly protective effects in a rat model of coronary occlusive myocardial infarction, whereas the water soluble BAT analogue, 4-Oxy-3,5-ditretbutylphenyl phosphonic acid sodiate (SFN-6), 100 mg/kg, displayed no protective effects. The natural antioxidant beta-carotene capable of displaying antioxidative activity at low partial O2 pressures was shown to reduce the size of postinfarct scar by 34% when given in a dose of 20 mg/kg.

[Effect of three retinoids on the growth of experimental tumors].

Influence of retinoid C17-diester retinyldimedone and L-tocopherylretinoate on the growth of transplanted tumors was investigated in F1 (C57Bl/6 X CBA) strain of mice. The retinoids studied proved to be less toxic than retinoic acid. Both retinoid C17-diester and L-tocopherylretinoate reduced growth of cervical cancer, while retinyldimedone inhibited growth of Lewis carcinoma (lung tumor) and of stomach carcinoma.

[Effect of synthetic beta-carotene on the formation of cytolytic T-lymphocytes].

The effect of intraperitoneal injection of beta-carotene in different doses on the formation of cytolytic T lymphocytes (CTL) in a one-way mixed lymphocyte culture (MLC) of allogeneic mice was studied. The maximal cytotoxic activity of lymphocytes was attained in the MLC with splenocytes of mice which received 10 mg/kg beta-carotene 6 days before experimentation. The correlation was studied between the beta-carotene ability to stimulate CTL formation and antineoplastic activity.

[Effect of native vitamin A metabolites and their 4-oxo derivatives on formation of specific cytolytic T lymphocytes].

Immunomodulating effect of some structural derivatives of retinoic acid (RA) on formation of specific cytolytic T lymphocytes (T killers) was studied in mixed cell culture of spleen lymphocytes from allogenic mice. Native vitamin A metabolites (RA, 13-cis-RA) and the structure-like substances (C15-C20-retinoids and others) at 10(-6) = 10(-7) M concentrations increased 2-2.5-fold the formation of T killers in vitro after stimulation of the lymphocytes by suboptimal doses of allogenic X-ray irradiated cells, the lymphocyte proliferation was inhibited in the mixed culture at 10(-5) M and higher concentrations of the substances.

[Antitumor and toxic properties of retinoid C15].

A study was made of antitumor and toxic properties of retinoid C15 which has some characteristic structural features of retinoic acid natural metabolites; such as ethyl-2E, 4E-3-methyl-5-/2,6-dimethyl-6-ethoxycarbonyl-/3-oxo-1-cyclohexene-1-yl/-2,4-pentadienoate. The substance inhibited the growth of transplantable tumors of the uterine cervix. Lewis carcinoma and rumen cancer.