[The role of eicosanoids and progesterone in the ovulation of the oocytes in the common frog]. / Rol' éikozanoidov i progesterona v ovuliatsii ootsitov travianoi liagushki.

Prostaglandin F2 alpha (1-5 micrograms/ml) stimulated ovulation in vitro of Rana temporaria oocytes in the absence of pituitary suspension and potentiated the effects of progesterone. The inhibitor of cyclooxygenase indomethacin (0.01-10 micrograms/ml) decreased the rate of oocyte ovulation stimulated by the pituitary suspension. An increased pituitary suspension concentration decreased the inhibitory effect of indomethacin. Indomethacin did not affect oocyte ovulation stimulated by prostaglandin F2 alpha or progesterone. The inhibition of ovulation by the chloride channel blocker SITS (10 microM) is partly relieved by prostaglandin F2 alpha or progesterone but completely eliminated by their mixture.

[The effect of an inhibitor of chloride channels and of media with a decreased concentration of chlorine ions on the ovulation of oocytes in the common frog]. / Vliianie ingibitora khornykh kanalov i sred so snizhennoi kontsentratsiei ionov khlora na ovuliatsiiu ootsitov travianoi liagushki.

Ovulation of the Rana temporaria oocytes stimulated in vitro by the suspension of homologous pituitaries is suppressed by the chloride channel inhibitor SITS and media with reduced concentration of chloride ions. SITS and media with reduced concentration of chloride ions do not affect the progesterone-stimulated ovulation of oocytes. The mechanism of stimulating the effect of the gonadotropins on ovulation of the amphibian oocytes is discussed.

[The effect of a chloride channel inhibitor and of media with a decreased concentration of chlorine ions on spontaneous oocyte maturation in the common frog and the clawed toad]. / Vliianie ingibitora khlornykh kanalov i sred so snizhennoi kontsentratsiei ionov khlora na spontannoe sozrevanie ootsitov travianoi i shporysevoi liagushek.

Chloride-deficient media (irrespective of anions substituted for chloride) increased the rate of spontaneous maturation of follicle-enclosed (FEOs) and denuded oocytes in Rana temporaria and Xenopus laevis. The chloride channel blocker SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonic acid) (10 microM) significantly decreased the rate of the spontaneous maturation of the FEOs and oocytes. The addition of 10 mM (instead of 2.7 mM) calcium ions to the gluconate solution significantly increased the rate of the spontaneous maturation of FEOs of R. temporaria if it was low in the gluconate solution, and decreased it if it was close to 100%.

[The role of chloride channels and chlorine ions in regulating the in-vitro chorionic gonadotropin-stimulated maturation of oocytes in the clawed toad]. / Rol' khlornykh kanalov i ionov khlora v reguliatsii sozrevaniia ootsitov shportsevoi liagushki, stimulirovannogo in vitro khorionicheskim gondaotropinom.

The blocker of chloride channels SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonic acid) (1 and 10 microM) reliable inhibited maturation of Xenopus laevis oocytes stimulated in vitro by human chorionic gonadotropin (5-40 MU/ml) and decreased the progesterone content of the incubation medium. The effect of SITS was dose-dependent and decreased with the increase of the hormone concentration. When the chloride ions in the medium were substituted for equimolar concentrations of sodium, potassium and calcium glutamates or of sodium or potassium chlorides for, respectively, glutamine and aspartate, the percentage of definitive oocytes (1.2-1.4 mm), maturing under the influence of human chorionic gonadotropin and the progesterone contents of the incubation medium increased, the certain part of smaller oocytes (0.9-1 mm).

[Oocyte maturation and activation in the common frog and the clawed toad under the action of divalent cations]. / Sozrevanie i aktivatsiia ootsitov travianoi i shportsevoi liagushki pod deistviem dvukhvalentnykh ionov.

Maturation of Rana temporaria and Xenopus laevis oocytes was induced by solutions containing Mn2+ and Co2+ ions. Completion of oocyte maturation was estimated by the following criteria: (1) appearance of the maturation promoting factor (MPF) in the oocyte cytoplasm and (2) oocyte capacity to activation and formation of male pronuclei from the injected sperm nuclei. X. laevis oocytes matured under the effect of Co2+ ions were shown to contain MPF. Oocytes of both species matured under the effect of either ions could not be activated by pricking with a needle and injected sperm nuclei didn't transform into pronuclei. R. temporaria oocytes matured under the effect of ions in late spring, when natural spawning takes place, showed spontaneous activation.

[[125I]-antigammaglobulin antibodies as universal reagents in radioimmunochemical methods of investigation]. / [125I]antigamma-globulinovye antitela kak universal'nyi reagent v radioimmunokhimicheskikh metodakh analiza.

A new indirect radioimmunochemical method based on the use of [125I]-anti-IgG-antibodies as universal detecting reagents is proposed. Its first step consists in the antibody binding to the antigen to be analyzed; the second step -- in immunoadsorption of the non-bound antibodies by water-insoluble sorbents prepared by chlorocarbonic acid isobutyl ester copolymerization of antigens with serum albumin or by immobilization of the antigen on Sepharose. The third step is the determination of the amount of sorbent-bound antibodies by means of [125I]-anti-IgG-antibodies. The method proposed was used for quantitative estimation of prolactin, somatotropin, lutropin, BB-isoenzyme of human creatine phosphokinase, testosterone and 5 alpha-dihydroxytestosterone. The method does not employ labelled antigens and is highly sensitive and highly specific.

[Formation of the cortical reaction in the process of oocyte maturation in the starred sturgeon]. / Stanovlenie kortikal'noi reaktsii v protsesse sozrevaniia ootsitov sevriugi.

The chronology of maturation process and cortical reaction development was studied in the Volga sevryuga oocytes. The germinal vesicle breakdown was first noted at 14 tau 0 following the injection of hypophysial suspension to the female and observed in the vast majority of oocytes at 17 tau 0; different phases of the I maturation division were found at 21 to 25 tau 0 and metaphase II at 33 tau 0. The ability to respond by cortical reaction to the activating stimulus (glass needle pricking) was first observed at 17 tau 0, i.e. soon after the germinal vesicle breakdown, but the appearance of the ability for cortical reaction was not connected causatively with the latter process. The cortical reaction in the maturing oocytes (17 to 25 tau 0) is characterized by the following features: in some oocytes the rate of the wave of granule breakdown is much lower than in the mature eggs; in ca. 80% of oocytes with the normal rate of cortical reaction the process of release of the contents of cortical granules in inhibited in the animal pole region and accordingly the contact of cytoplasm with the membranes is preserved in this region for a long time.

[Cortical reaction in starred sturgeon eggs following fertilization and artificial activation]. / Kortikal'naia reaktsiia v iaitse sevriugi pri oplodotvorenii i iskusstvennoi aktivatsii.

An electron microscopical study of the fertilized sevryuga eggs has shown that 3 sec after insemination the most cortical granules in the region of the animal pole are already dehiscing and 10 to 30 sec the cortical granules release their contents under the membrane, but between the groups of cortical granules the contact of the cytoplasm with the membrane is still preserved. The full separation of the membrane observed under the light microscope at these times of fixation (San Felice fluid) is an artifact due to changes in the cortical cytoplasm properties. The rate of spreading of the cortical reaction over the egg surface is reduced from the animal pole to the vegetative one. By the criterion of the first changes discernible under the light microscope (formation of vacuoles and cytoplasmic threads between them) the maximal rate in the region of the animal pole amounts 360.5 mcm/sec and the average rate of the whole egg 46.5 mcm/sec; by the criterion of membrane separation the average rate amounts to 26.8 mcm/sec (at the temperature 21.9 degrees). The average rate of spreading of the cortical reaction in the sevryuga eggs is close to that in the sturgeon (Acipenser güldenstädti) and exceed ca. 3 times that in the sea urchin and teleostean eggs. The cortical reaction spreads at the same rate both in the fertilized and activated sevryuga eggs.

[Simple and rapid heterologous method of radioimmunochemical determination of luteinizing hormone in the blood serum of rats. 2. Specificity of the method]. / Prostoi i bystryi geterologichnyi metod radioimmunokhimicheskogo opredeleniia liuteiniziruiushchego gormona v syvorotke krovi krys. II. Spetsifichnot' metoda.

The Heterologous hard phase radioimmunochemical method (RICM) of luteinizing hormone (LH) determination was tested in a number of experimental models for specificity. The results obtained demonstrated that a possible factor of cross reaction with the thyrotropic hormone (TTH) and the folliculo-stimulating hormone (FSH) was apparently insignificant in determination of LH in rat serum. This conclusion was based on the following. An immunosorbent used in RICM, prepared from the antisera of rabbits immunized with sheep LH, failed to interact with the FSH of rat hypophysis extracts. TTH-releasing hormone failed to alter the level of the immunoreactive LH in rat serum, whereas LH-releasing hormone increased 31-fold the LH concentration in 20 min. Besides, by means of RICM there was recorded a marked increase of the LH in the serum of rats after ovariectomy and a fall of the LH concentration in response to the administration of estradiol together with progesteron to such rats.

[Simple and rapid heterologous method of radioimmunochemical determination of luteinizing hormone in the blood serum of rats. 1. Basic principles of the method]. / Prostoi i bystryi geterologichnyi metod radioimmunokhimicheskogo opredeleniia liuteiniziruiushchego gormona v syvorotke krovi krys. 1. Osnovy metoda

Possibilities of creation of a radioimmunochemical method (RICM) of determination of the luteinising hormone (LH) were studied. The method is based on the application in the binding system of a water-insoluble immunosorbent obtained by copolymerization of antisera with isobutyl ester of chlorocarbonic acid. The antisera were obtained by immunization of rabbits with a highly-purified LH isolated from sheep hypophyses. The method is rapid and precise, and is carried out in a single stage. Significant results of RICM in the LH determination can be obtained with the minimal two-hour incubation time. Using different amounts of the immunosorbent in the reaction mixture with the same indicator dose of I125-LH it is possible to vary the method sensitivity (from 0.05 to 5 ng/test).