[Radiosensitization of human tumor HeLa cells induced by methyl ester of 6-oxo-6-[2,2-ethylenedioxy-5-(dimethoxycarbonylmethyl)-cyclope nt- 1-yL]-hexanoic acid].

Methyl ester of 6-oxo-6-[2,2-ethylenedioxy-5-(dimethoxycarbonylmethyl)- cyclopent-1-yl]-hexanoic acid (7-keto-9,9-ethylenedioxiprostanoid, that is analogue of 11-deoxy-PGE1 with modified chains) at concentration 10(-6) mol/l displayed maximal (25%) sensitizing effect when was tested in a range of concentrations 10(-7)-10(-5) mol/l and HeLa cells were gamma-irradiated at dose of 2 Gy, that was compared with metronidazol action. Optimal time of prostanoid contact with cells was between 30 and 60 min, and metronidazol--60 min. Prostanoid effect was exhibited at irradiation doses from 2 to 4 Gy and reached maximum of 46% at 4 Gy, its DMF was 1.

[The modification of a radiation lesion with 9a-homo-13-thiaprostanoids].

The radioprotective properties of 12 compounds of 9a-homo-13-thiaprostanoid series were investigated under gamma irradiation using the molecular model of beta-carotene radio-oxidation in oleic acid in vitro, erythrocyte radiomimetic model in ex vivo-in vitro system as well as in vivo radiation damage in mice. Most of these compounds stimulated the radio-oxidation of beta-carotene, however in this model two prostanoids with natural alpha-chain displayed radioprotective properties. Expressed membrane stabilizing effect of two 9a-homo-13-thiaprostanoid nor-analogues was revealed in radiomimetic model experiments.

[The mechanism of the immunostimulating action of trimezon].

The influence of various concentrations (10(-9) - 10(-6) M) of the new immunostimulator trimezon of 8-aza-D-homogonan range upon in vitro proliferation of human lymphocytes, stimulated by PHA 0.5-10.0 micrograms/ml), was investigated by 3H-thymidine incorporation analysis.

[Immunomodulators with an 8-azasteroid structure as inducers of liver cytochrome P-450].

Two structural analogues of D-homo-8-azasteroids, both an immunostimulant and an immunodepressant, are inductors of the liver cytochrome P-450 in animals. This capability was shown by means of both a decrease of the hexenal sleep duration in the pharmacological test and an increase of the quantity of cytochrome P-450 and the rate of N-demethylation of aminopyrine in the biochemical assays.