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The influence of ionic and non-ionic contrast media on the ex vivo hemostasis in rabbits was studied for ionic urografin (76 %), non-ionic ultravist-300, and non-ionic omnipaque-300 intravenously injected in medium and high doses (1.5 ml/kg and 3.0 ml/kg, respectively). Ionic urografin (1.5 ml/kg) almost did not influence the level of hemostasis ex vivo. Non-ionic contrast media (ultravist and omnipaque) in the medium diagnostic dose (1.5 ml/kg) activated the hemostasis, the effect being much more pronounced in the case of omnipaque. Dose-dependent action was observed for both ionic and non-ionic contrast media.

Antitumor activity of a new highly active promising gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one (butagest) was studied in mice with model cervical carcinoma (RShM-5). The reference drug was medroxyprogesteron acetate (MPA, Depo Provera) used in clinics. The new preparation introduced perorally in a dose of 1 mg per mice inhibited the model tumor growth by 73%, which was 18% (p < 0.01) more effective than the action of the reference drug MPA. The effect of the new gestagen was also studied in vitro with respect to human breast carcinoma of the MCF-7 line and human cervical carcinoma HeLa. The viability of the tumor cells was studied during a 6-day incubation with the drug at a concentration of 10(-7)-10(-5) M (MTT test). The reference compounds were progesterone and MPA. These drugs suppressed the growth of both MCF-7 and, in higher concentrations, of HeLa. Butagest inhibited the growth of HeLa in all concentrations. Thus, the new gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one is capable of suppressing the viability of human breast carcinoma and human cervical carcinoma, being comparable or even more effective than the reference drugs.

Information is presented on the classification of serotonin receptors which is based on the results of pharmacological and radioligand analysis. The genetic and biochemical characteristics of the types and subtypes of serotonin receptors are discussed. The role of serotonin receptors of the central and peripheral nervous system and the role of some effector cells and organs in the regulation of their functional activity is described.

In concentrations of > or = 10(-5) mol/liter nistranol (11 beta-nitroxy-9 alpha-hydroxy-ethynylestradiol-diacetate) demonstrated cardiac and vascular activity in vitro. It caused concentration-dependent and reversible increase of the contractile parameters of an isolated atrial appendage of rats. A three-phase effect of nistranol on a isolated rat thoracic aorta was encountered: vasodilatation-vasoconstriction-vasodilatation. Anti-ischemic and antinecrotic effects of nistranol were noted in experimental myocardial infarction.

It has been shown that the GABAergic system of the myometrium takes part in regulation of uterine contractility during the development of pregnancy Fenibut and phenazepam exhibit a specific uterotropic effect. The uterodepressant effect of fenibut is realized via the inhibiting GABA-receptors of the myometrium. The uteroinhibiting effect of phenazepam is mediated through the interaction with the postsynaptic GABA-benzodiazepin-C1-receptor complex of the myometrium.

The mechanisms binding X-ray contrast media and magneto-resonance contrast media of various structure with human serum albumin and gamma-globulins were studied. Equilibrium dialysis showed that X-ray contrast media bind with blood plasma proteins, but magneto-resonance contrast media do not interact with these proteins. Electrostatic forces play a significant role in formation of complexes of X-ray contrast media with human blood serum albumin. With increase in the size of the molecule of the X-ray contrast media their affinity for the binding sites of this protein diminishes. The formation of complexes of X-ray contrast media with human blood plasma gamma-globulins occurs through hydrophobic interactions. Increase in the size of the molecules of these media reduces their affinity for the gamma-globulin binding sites.

It is shown that Ultravist makes it possible to receive clear visualization of vessel channel in the zone "of interest" without changing functional conditions of heart vascular system and biochemical blood parameters (level of erythrocytes, bilirubine, urine nitrogen, activity of aspartataminotransferase). In concentration 30 mg/ml in vitro and in vivo Ultravist decreases a viscosity limit not affecting other rheological properties of blood. A mechanism of the found Ultravist effect and prospects of its application in practice for children are considered.

In in vivo and in vitro experiments, androgen anabolic steroid agents (testosterone, methandrostenolone) and dexamethasone showed a dose-dependent inhibition of PHA-stimulated proliferation of C57BL/6 mice thymocytes. The phytoecdysteroidal anabolic steroid ecdystene failed to inhibit thymocytic proliferation. The competitive radioligand analysis was used to show that testosterone and methandrostenolone displace the androgenic steroid mibolerone from lymphocytes. The findings provide evidence that lymphocytes have specific binding sites for androgen-anabolic steroids.

The impact of radio-opaque agents on human blood plasma water pool was studied by using relaxation proton magnetic resonance methods with a pulse gradient of magnetic field. The findings suggest that blood plasma water imbalance was induced by human serum albumin dehydration processes after RCN-HSA interaction.

The effects of radiopaque agents on peripheral blood T-lymphocyte blast transformation were in vitro studied in healthy donors. It was shown that depending on the dose and type, radiopaque agents activated spontaneous proliferation of these cells and inhibited or activated PGA-induced proliferation. An individual sensitivity of peripheral blood lymphocytes to the radiopaque agents was revealed. There was a positive correlation between the functional response of peripheral blood lymphocytes to PGA and the degree of bilignost-induced inhibition of this reaction. There was also antagonism of some radiopaques in response to peripheral blood T-lymphocyte blast transformation.

The in vivo and in vitro effects of radioopaque agents such as bilignost, iodamide, and triombrast on blood thromboxane B2 (TxB2) and prostacyclin levels were studied in man and rats. These radioopaque agents were demonstrated to increase prostacyclin levels and to decrease TxB2 in the plasma by 40%, as evidenced by urography when given in vivo (1-2 g/kg) and in vitro (2.5.10(-2) M and 2.5.10(-3) M).

Fluorescence was used to examine the effects of nitroglycerin (60 microM) on basal and mitogen-induced (ConA, 25 micrograms/ml) Ca2+ levels in the human lymphocytic cytoplasm. Calcium-blocking effect of nitroglycerin was markedly shown in the medium containing 1 mM CaCl2 and virtually absent in calcium-free buffer. It is concluded that nitroglycerin affects cellular Ca2+ entry. A 120-minute preincubation led to a complete loss of the inhibitory effects of the drug on mitogen-induced Ca2+ responses of lymphocytes. Human lymphocytes are proposed as an experimental model for investigating the effects of nitrates and the mechanisms of their tolerance development.

A new micromethod for measuring the intensity of free radical oxidation reactions, based on an analysis of "fast flash" of iron-induced chemiluminescence parameters has been designed. The optimal concentration parameters of the reaction system have been determined. The effects of the antioxidants mexidol, probucol sodium dibunat and fenoxan have been examined in vitro.