[The effect of pregna-D'-pentarans on myometrial contractile activity in pregnant rats]. / Vliianie pregna-D'-pentaranov na sokratitel'nuiu aktivnost' miometriia beremennykh krys.

The authors studied the effect of synthetic gestagens on spontaneous contractility of the myometrium in pregnant rats. The direction of the effect of progesterone and its analogs on the contractility is determined by stereochemistry of the linkage of rings A and B of the steroid molecule. Compounds possessing translinkage (5 beta-steroids) increase the amplitude of myometrium contraction, whereas their analogs with cms-coupling of rings A and B (5 alpha-steroids), and 4,5-unsaturated steroids reduce it.

[An experimental study of the cardiovascular activity of nistranol]. / Eksperimental'noe issledovanie serdechno-sosudistoi aktivnosti nistranola.

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.

[Immunologic response of the body in thyroid gland involvement due to incorporation of varying doses of 131I]. / Immunologicheskie reaktsii organizma pri porazhenii shchitovidnoi zhelezy, vyzvannom inkorporirovaniem razlichnykh doz 131I.

The body's immunological responses were examined in thyroid damage caused by the incorporation of varying 131I doses. The in-take of 131I in doses of 37, 74, and 148 KBc/g body weight caused reductions in the murine blood concentrations of thyroxin following 30, 60, and 180 days. The blood levels of triiodothyronine decreased 180 days after administration of 131I in a dose of 74 KBc/g body weight and 30, 60, and 180 days after incorporation of the radioisotope in a dose of 148 KBk/g body weight. Decreased concentrations of the both hormones were followed by the suppression of a humoral immune response to sheep red blood cells, diminished cell-mediated immunity in the mixed culture of lymphocytes. The inhibition of immune responses was correlated with the changes in the level of triiodothyronine.

[Specifics of endocrine regulation of digestion in patients with esophageal neoplasms after esophagogastroplasty]. / Osobennosti éndokrinnoi reguliatsii pishchevareniia u bolnykh rakom pishchevoda posle ézofagogastroplastiki.

In 67 patients with esophageal cancer, the peculiarities of endocrine regulation of alimentation after resection and plasty of the esophagus, using an isoperistaltic gastric tube were studied. Of these patients, 15 underwent correction of the disorders revealed. Accelerated evacuation of the content from a gastric transplant is accompanied by atony of the pylorus and is due to relative incompetence of neuroendocrine elements in gastric and duodenal mucosa (presence of a small amount of EC- and P-cells). Use of pentagastrin at the early postoperative period permits to accelerate the process of formation of the compensatory-adjusting mechanisms in the system of alimentation due to increase in functional activity of EC- and I-cells.

Force-frequency relations in hypertrophic heart muscle: a mathematical model for excitation-contraction coupling.

Static and dynamic chrono-inotropic responses were recorded from both normal and hypertrophic rat auricular myocardium. The slope of the static force-frequency relation for hypertrophic hearts was steeper than that for control hearts. Computer experiments were designed to study the cellular mechanisms underlying the changes in the force-frequency response associated with heart hypertrophy, with the aid of a mathematical model for excitation-contraction coupling in rat heart. A set of equations was derived which permitted to study the effects on the chronoinotropic relations of both the geometrical dimensions of cardiomyocytes and the sarcoplasmic reticulum, and of the variation in activity of mechanisms for Ca movements through the sarcolemma and the sarcoreticular membrane. A comparison of data obtained from simulated and real experiments suggested that the features characteristic of force-frequency relations for hypertrophic heart are a result of an enhanced volume of intracellular Ca-stores rather than of the total volume of the cardiomyocyte.

[Chronoinotropic reaction of the hypertrophied myocardium using an electromechanical coupling mathematical model]. / Issledovanie khornoinotropnoi reaktsii gipertrofirovannogo miokarda s pomoshch'iu matematicheskoi modeli élektromekhanicheskogo sopriazheniia.

Static and dynamic chrono-inotropic responses were recorded from both normal and hypertrophic rat auricular myocardium. The slope of the static force-frequency relation from hypertrophied heart was steeper than in the control hearts. The cellular mechanisms underlying changes in the force frequency response associated with hypertrophy of the heart were studied by means of a mathematical model of excitation-contraction coupling. The characteristic features of hypertrophied heart force-frequency relations are shown to be due to the enhanced volume of the intracellular Ca-stores in contrast to the total volume of the cardiomyocyte.

[Endocrine function of the pancreas after radical surgery in esophageal cancer]. / Endokrinnaia funktsiia podzheludochnoi zhelezy posle radikal'nykh operatsii pri rake pishchevoda.

Postoperative levels of insulin and morphological pattern of beta-cells of islets of Langerhans were studied in 27 esophageal cancer patients following one-stage esophageal resection or repair with the gastric pedicle graft and extracavitary cervical shunt. There is a postoperative inhibition of secretory activity of the insulin pancreatic apparatus which recovered on 120 postoperative day. These shifts resulted from dystrophy of the beta-cells.

[Ionic mechanism of the Woodwors staircase]. / Ionnyi mekhanizm lestnitsy Vudvorsa.

Analysis of single-chamber model of electromechanical coupling in the myocardial cell has shown that Woodwors staircase can be imitated in two cases: 1) stationary input current Ca2+ strongly exceeds the potential-dependent uptake of Ca2+ into the cell through the sarcolemma; 2) the action potential (AP) is shortened abruptly with an increase of the myocardium stimulation frequency. The experiments performed on a fragment of the frog heart ventricle supported the conclusions of the model. Blocking of Ca-channels with nifedipine (10(-6) g/mol) at the background of isotonic substitution of 70% of NaCl resulted in the development of "negative staircase" with an increase of stimulation rhythm. An abrupt shortening of AP after rest at joint action of adrenaline (10(-6) g/ml) and blocker of Ca-channels D-600 (10(-6) g/ml) was accompanied by Woodwors staircase.

[Hypophyseal-thyroid system function of animals in the early periods after tumor transplantation]. / Funktsional'noe sostoianie gipofiz-tireoidnoi sistemy zhivotnykh v rannie sroki posle perevivki opukholi.

The signs of disintegration of hypophyseal-thyroid system function with predominant iodine uptake by thyroid gland cells are detected in the animals during the first 3 days after sarcoma M-1 inoculation. Dissimilar changes in magnesium ion levels are seen in the peripheral blood plasma and thyroid tissue homogenate of the animals with inoculated tumor and injected with non-specific antigenic stimulant.