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Biomedical subjects

V I Tsirkin

Publications and source records attributed to V I Tsirkin.

At least 19 recordsLinked to original sources
PubMed2004

Ability of L-histidine to decrease desensitization of the myometrium to epinephrine.

Experiments were performed with 62 longitudinal strips of the uterine horns from 10 nonpregnant rats. The ability of continuously infused epinephrine in high concentration (10(-6) g/ml, 30 min) to suppress spontaneous contractions due to activation of beta-adrenoceptors progressively decreased, which was associated with receptor desensitization. Histidine in a concentration of 3 x 10(-11) g/ml had no effect, while in concentrations of 3 x 10(-8), 3 x 10(-7), and 3 x 10(-6) g/ml decreased the degree of desensitization. Our results indicate that histidine not only potentiates beta-adrenoceptor activation, but also prevents the development of desensitization. These data should be taken into account during therapy with beta-adrenoceptor agonists.

Animals↗
PubMed2004

Histidine increases beta-adrenoreactivity of myocardium in frogs.

Histidine (3x10(-5) g/ml) had no effect on contractility and chronoinotropic relationships in frog myocardium, but rapidly and reversibly increased myocardial beta-adrenoreactivity (increased myocardial response to 7x10(-8), 3x10(-7), and 4x10(-6) g/ml epinephrine) and potentiated the positive effect of epinephrine (7x10(-8), 3x10(-7) g/ml) on chronoinotropic relationships in the myocardium. Histidine is considered to be a component of endogenous sensitizer of beta-adrenoceptors in human blood modulating the function of cardiomyocytes.

Animals↗
PubMed2003

Effect of physical training on blood level of endogenous modulators of beta-adreno- and m-cholinoreactivity in patients with a history of myocardial infarction.

The relative content of myocyte-active factors and endogenous muscarinic receptor blocker in the blood increased, while the concentration of endogenous beta-adrenoceptor sensitizer decreased in coronary patients with a history of acute myocardial infarction. Physical training produced a therapeutic effect, normalized the content of these factors and, probably, improved beta-adrenergic and muscarinic cholinergic regulation of the heart and vessels.

Animals↗
PubMed2003

[Effect of ozone exposure on contractile activity and chemoreactivity of uterus horns longitudinal muscles of nonpregnant rats].

With the purpose of studying the mechanism of ozone action on uterus smooth muscles it was investigated the influence of ozone-content (approximately 0.50 mkg/ml) Krebs' solution or its 10- and 100-fold dissolution on contractile activity and beta-adrenoreactivity of 56 longitudinal strips of uterus horns of 17 nonpregnant rats. Ozone at concentration approximately 0.50 mkg/ml (but not in concentration of approximately 0.05 and approximately 0.005 mkg/ml) reversibly raised frequency, amplitude and total contractile activity of intact myometrium strips, and also fast and reversibly reducel its beta-adrenoreactivity, i.e. decreased of inhibitory action of adrenaline (10(-8), 10(-7), 10(-6) g/ml), but did not change uterostimulatory effect of acetylcholine (10(-6) g/ml) and oxiyocin (5 x 10(-4) ME/ml), what evident about specificity of ozone beta-adrenoblokate effect. Ozone (approximately 0.50 and 0.05 mkg/ml) did not change ov value of potassium contracture of myometrium strips which was depolarized by hyperpotassium (60 mM KCL) Krebs' solution, but reduced inhibitory action of adrenaline (10(-8) g/ml). The question is being discussed about mechanisms of ozone beta-adrenoblocade actions, about clinical role of this phenomenon, and the possibility of using beta-adrenoreceptor sensibilizators direct action (histidine, tryptophan, tyrosine, trimetazidin and mildronat) at ozonotherapy with the purpose reduction of its negative effects.

Acetylcholine↗
PubMed2003

[Effect of physical training on M-cholinergic-blocking activity of blood serum in acute coronary disease].

On 93 longitudinal strips of 31 rats' uterus horns, M-cholinoblocking agent activity in 50-, 100-, 500-, 1000- and 10,000-fold dilution of the blood serum taken from 10 healthy older subjects and 40 patients after an acute coronary incident, was studied, 10 patients being engaged in physical training. Findings suggest presence of an endogenous M-cholinoreceptor blocking agent in the blood with lisophosphatidylcholin as the basic component. An acute coronary incident seems to reduce the efficiency of the M-cholinergic effect on the heart and vessels.

Acetylcholine↗
PubMed2002

[The role of endogenous modulators of chemoreactivity in the regulation of coronary blood flow].

32 circulatory bands of coronary arteries of 5 pigs were studied. It has been revealed that the bands develop long-term tonic contraction activity in Krebs's solution (30 mM of KCl). In this case adrenalin in concentration of 10(-7) g/ml causes mild relaxation. In concentration of 10(-6) g/ml, it causes obvious relaxation. Trimetazidin and mildronat do not affect tonic contraction of the bands. They can quickly and reversibly increase relaxation effects of adrenaline. The preparations can increase ten-fold beta-adrenoreactivity of smooth muscles. This shows an important role of endogenic sensibilizers of beta-adrenoreceptors in regulation of coronary blood flow in humans.

Adrenergic beta-Agonists↗
PubMed2000

[Effect of the long-term exposure of the isolated myometrium from nonpregnant rats to serum from pregnant women on its contractile activity and the beta-adrenergic reactivity].

Pregnant women's blood serum (the whole as well as 50- and 100-diluted) did not alter parameters of spontaneous motility, i.e. it did not affect the uterus myocytes' spontaneous motility, whereas the whole or 50-diluted serum raised considerable the rat myometrium's beta-adrenoreaction. The data obtained suggest that the beta-adrenoreaction of the rat uterus' myocytes increases after a prolonged contact with pregnant women's blood serum which may be due to the beta-adrenoreceptor synthesis activation and to an increase in their concentration because of diffusion from the blood serum. This suggests existence of humoral mechanisms of the myometrium beta-adrenoreaction regulation, the mechanisms creating the optimum uterus' contractile activity.

Adrenergic beta-Agonists↗
PubMed1989

[Endogenous beta-adrenomimetic substance as a constituent of the adrenergic beta receptor blocking mechanism].

In order to reveal endogenous beta-adrenomimetic in the blood the authors proposed the biological testing of the serum and plasma on the isolated myometrium of the rat. For this purpose obsidan was used as a beta-adrenoblocker. It was shown that endogenous beta-adrenomimetic different from adrenaline was present in the blood of males, nonpregnant and pregnant females and parturients. Besides, its concentration increased in pregnancy and remained high early in labor.

Adolescent↗
PubMed1989

[Changes in the strength of the beta-adrenoreceptor inhibiting mechanism on the eve of and during labor determined by the partusisten test].

Partusisten was examined for effects on uterine contractility in 28-36- or 38-42-week pregnant women and parturients. The agent was shown to result in inhibited uterine contractility in the pregnant and parturient females, the contractility was decreased before and particularly during labor, which was indicative of lower beta-adrenoreceptor inhibitory mechanism force.

Depression, Chemical↗