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S Stokłosowa

Publications and source records attributed to S Stokłosowa.

14 recordsLinked to original sources
PubMed2001

Prolactin binding analysis and immunohistochemical localization of prolactin receptor in porcine ovarian cells.

In the present study we searched for prolactin receptor (PRL-R) in porcine ovarian theca tissue (Tc) of small, medium and large follicles, as well as in early corpus luteum (ECL). The objectives of this investigation were: 1) comparison of the direct effect of PRL action on progesterone (P4) and estradiol (E2) secretion from Tc and ECL cells in culture with adequate effects caused by luteinizing hormone (LH). 2) detection of the presence and distribution of PRL-R in thecal tissue of porcine follicles and in ECL. Tissues were cultured as monolayers either in control M199 medium with calf serum or in medium either with PRL (100 ng/ml) or with LH (100 ng/ml). After 2 days in vitro cultured media were assayed for steroid concentrations by radioimmunoassays. Content and distribution of PRL-R were evaluated by Scatchard analysis and by an immunohistochemical assay. Separated theca layers as well as fragments of ECL were excised on dry ice, homogenized, and incubated with [125I]-PRL. PRL stimulated P4 secretion from Tc 10-fold versus controls. LH stimulated P4 secretion only 2.5-fold. E2 secretion was stimulated by PRL 2.7-fold and by LH 2.4-fold. LH enhanced P4 secretion from ECL cells by 18% while PRL increased P4 secretion by as much as 73%. Femtomol amounts of PRL-R protein were detected in theca tissues of medium and large follicles and also in ECL, which was in accordance with immunohistochemical results. The results showed for the first time the presence of PRL-R in porcine Tc and ECL.

Animals↗
PubMed2001

Three dimensional tissue and organ models in vitro: their application in basic and practical research.

Good and reliable three dimensional biomodel in vitro should mimic the in vivo structure and function of investigated tissue or organ. This can be achieved through the interaction of various cell types and the environment (extracellular matrix, as well as spatial cell contacts). While designing such a model it is necessary to find best nutritive and adhesive factors, to allow access to components of optimal matrix and to enable cell contacts in three dimensions. The response and function of such models reminds physiological function of tissue of origin. Over several years there has been an increasing number of experiments and publications reporting research involving spatial cell models. This model and its structural and molecular analysis clearly showed, that in comparison with conventional cultures, mainly monocultures grown as monolayers, spatial cultures resemble the in vivo situation with regard to cell shape and biological behaviour. Spatial arrangement of cells and the environment can direct tissue differentiation. Interesting example of the importance of the environment for the latter, is the finding that the ectopic implantation of embryonic cells transforms them into malignant tissue while the same cells located in the uterus undergo normal embryogenesis. The present review describes several three-dimensional models in vitro and their application in basic and practical studies. It is especially interesting and important in the light of developments of tissue modeling to obtain in vitro substitutes of damaged or impaired tissues and organs. Other demands come from animal protectionists who suggest replacement of experimental animals with cultures and tissue models in bio-, pharmacological, and toxicological assays. In response, European Union legislation introduces increasing restrictions on animal experiments. At last, researchers seek in vitro models which would enable avoiding discrepancies between in vitro and in vivo results.

Animals↗
PubMed1999

Enhanced proliferation and progesterone production by porcine granulosa cells cultured with pseudorabies virus growth factor (PRGF).

The objective of this research was to study possible interactions of pseudorabies virus growth factor (PRGF) with ovarian tissue. Granulosa cells isolated from porcine ovaries were cultured as monolayers for 6 days in a control medium without PRGF and in medium supplemented with different doses of this agent. Increased population density and change towards more fibroblastic-like shape of cells cultured with 10(9) I.U PRGF was observed when compared with control culture. The cells divided significantly faster during 6 days of culture under the influence of 10(3), 10(4), 10(5), 10(6), 10(7), 10(8) and 10(9) I.U./ml of PRGF at a dose dependent manner. PRGF in a dose 10(9) I.U. added to cultured cells isolated from small and medium follicles did not influence progesterone secretion . An increase of progesterone secretion under the influence of PRGF in all investigated days of cultures was observed in cells isolated from large preovulatory follicles. The marked increase in progesterone content in PRGF treated culture in doses of 0.5x10(7), 0.5x10(8), 0.5x10(9) I.U. was observed during 4 and 6 days of culture. The rise of progesterone content was not connected with increased number of secretory cells, but with a stimulation of production per cell. PRGF exerted no visible effect on progesterone secretion by granulosa cells from small and medium follicles cultured for 6 days. The presented in vitro data provide evidence for a local action of PRGF in the follicle depending on the stage of follicular development and duration of exposure. Precise relevance of the interaction of PRGF with follicular development requires further study.

Animals↗
PubMed1999

Effect of genistein, tyrphostin and herbimycin on prolactin-stimulated progesterone production by porcine theca and luteal cells.

The potential involvement of protein tyrosine kinases (PTK) in the mechanism of prolactin (Prl) action on ovarian cell steroidogenesis has not been elucidated and information about research on this subject is scarce. In this preliminary study pharmacological intervention was used to provide support for a possible involvement of tyrosine kinases in prolactin induction of progesterone secretion by porcine thecal and luteal cells. Material used in this experiment were cultures of porcine follicular theca interna and early corpus luteum cells. The former were isolated from, proestrous preovulatory follicles and the latter were obtained by enzymatic dispersion of luteal tissue. Three of tyrosine kinase inhibitors, genistein, herbimycin and tyrphostin, were applied. They act through different mechanisms, partially blocking Prl-stimulated progesterone secretion. Herbimycin at a dose of 3 microM inhibited Prl-stimulated progesterone secretion beneath the control level in theca and by 70% in luteal cells. Genistein at a dose of 45 microM inhibited Prl-stimulated progesterone secretion beneath the control level in theca and down to the control in luteal cells. On the other hand, tyrphostin at a dose of 100 microM only slightly suppressed Prl-stimulated progesterone secretion by thecal and luteal cells (33% and 40% respectively). This investigation is the first search for evidence of involvement of tyrosine kinases in Prl-stimulated progesterone production by ovarian cells in the pig.

Animals↗
PubMed1997

Organ culture as a model of studying follicular development and function of postnatal mouse ovaries.

Ovarian organ culture was used to study the influence of various gonadotropin hormones (100 ng FSH, 100 ng LH, 100 ng LH added together with 100 ng FSH; 1 i.u. hCG or 10 i.u. PMSG) on growth and development of follicles as well as on steroid secretion by ovaries of postnatal, 15-day-old mice. Ovaries were aseptically removed and single organs were placed on a piece of lens paper which was supported by a stainless steel grid in the small organ culture dish. The cultures were maintained in medium M199 supplemented with 5% of calf serum in a CO2 incubator at 37 degrees C. The morphological changes and steroid secretion measured by appropriate RIAs were studied. The stages of follicular development and the incidence of particular types of follicles were scored. Progesterone and estradiol were detected in the medium by radioimmunoassay. Differences between control and gonadotropin stimulated ovaries were found in the number of the ovarian follicles in more advanced maturation stages. There was increased number of multilaminar and antral follicles in FSH and FSH plus LH treated cells. The adding of gonadotropin hormones to the culture medium stimulated significantly progesterone secretion. The most significant effect was observed in media of cultures treated with LH and hCG. As to estradiol secretion the highest stimulatory effect was seen in cultures supplemented with FSH alone, together with LH and with PMSG. The organ culture technique applied in the current study could be a suitable model of studying the interaction of various factors as well as its effect on ovarian differentiation and on selection of dominant follicles. This system allows maintaining the structural integrity of the whole ovary, thus in the physiological functional status of the organ.

Animals↗
PubMed1996

The effect of microtubule-disrupting drugs on morphology, progesterone and prorenin secretion of bovine cultured ovarian theca cells.

The effect of three microtubule-disrupting drugs (vinblastine, colchicine and nocodazole) on basal and LH-stimulated secretion of progesterone and prorenin by bovine theca cells was studied. Microtubules were visualized immunocytochemically using a monoclonal antibody against the alpha-subunit of tubulin and a secondary antibody conjugated with rhodamine. Progesterone and prorenin secretion were detected by adequate radioimmunoassays. Theca cells treated with LH alone or with a combination of LH, colchicine and vinblastine, showed round shape and disorganization of microtubules which were more obvious than after treatment with the two disrupting drugs alone. Nocodazole or LH treatment alone resulted in the formation of numerous cell processes, conspicuously different in shape from those in the controls. All three drugs increased basal progesterone secretion independently on the dose, but were without effect on basal prorenin secretion. LH-stimulated progesterone secretion was significantly suppressed by each of the three drugs while LH-stimulated prorenin secretion was decreased only by high doses of vinblastine and nocodazole. Colchicine in all three doses used did not exert any significant effect. The results obtained suggest that microtubules are involved in progesterone but not in prorenin secretion.

Animals↗
PubMed1994

Evidence for inhibition of steroid hormone secretion by arginine vasotocin (AVT) in tissue culture of isolated ovarian follicular cells.

Two follicular compartments, granulosa (G) and theca interna (T) cells isolated from porcine ovaries were cultured alone or in co-culture (GT). Cells were grown as monolayers in a control medium without hormone and in a media supplemented with arginine-vasotocin (AVT) at a concentration of either 10(-7)M or 2 x 10(-7)M. Progesterone (P4), estrogen (E2) and androgen (A) concentrations in the culture media were taken as measures of the effect of AVT on the function of follicular cells. Steroids were analysed by radioimmunoassay. AVT action in this culture system was expressed as a decrease in progesterone secretion by cultures of granulosa cells alone, and especially as a change in the pattern of estradiol and androgen secretion by co-cultures. Control T and G cells cultured alone secreted small amounts of A (238.0pg/10(5) cells, 27.3pg/10(5) cells, respectively), and E2 (272.5pg/10(5) cells, 10.6pg/10(5) cells, respectively) while in co-culture these two cell types interacted and the result of this positive interaction was a significant increase in secretion of these two steroids (941.0pg/10(5) cells androgen secretion and 854.1pg/10(5) cells estradiol secretion). This phenomenon is similar to that observed in the intact follicle in vivo. AVT introduced to the culture medium impaired the effect of this positive interaction of mixed G and T cells on the production of high levels of E2 and A by untreated co-cultures.

Androgens↗
PubMed1994

Adherence of lymphocytes to Leydig cell surface as an effect of the functional activity of Leydig cells in vitro.

Formation of lymphocyte rosettes around unstimulated and/or LH/hCG-treated Leydig cells in culture as well as in suspension was investigated. The ability of Leydig cells to interact with lymphocytes was positively correlated with their steroidogenic activity, as measured by means of a histochemical test for delta (5)3 beta-HSD activity and by radioimmunoassay for androgen level in culture media. In order to rule out nonspecific binding of lymphocytes, rosette specificity tests were performed. Time-dependent dynamics of cell-cell interaction was also followed. A phenomenon resembling phagocytosis of the adhered lymphocytes was observed after 4 h of co-culture. Morphology of this interaction was examined under light microscope and transmission electron microscope.

3-Hydroxysteroid Dehydrogenases↗
PubMed1985

The endocrine activity of isolated follicular cells of the carp ovary in primary culture.

Oocytes were isolated from the ovaries of carp females of one breed. Interstitial tissue was mechanically removed in order to obtain single oocytes surrounded only by the follicular envelope. Such a preparation was trypsinized at room temperature and also with greater success at 37 degrees C. The follicular cell suspension contained both cells and cell clumps. It was the mixture of theca (T) and granulosa (G) cells. The temperature of 37 degrees C was preferable for the successful growth of the cells in tissue culture. The cells were grown as monolayers in Leighton tubes in Medium 199 supplemented with calf serum. Activity of delta 5, 3 beta-hydroxysteroid dehydrogenase (delta 5, 3 beta-HSD) was detected in the growing cells by a histochemical test. Culture media were analyzed for estrogen, androgen, and progesterone content by appropriate radioimmunoassays. Follicular cells prior to and in culture exhibited activity of the delta 5, 3 beta-HSD and secreted steroid hormones into the culture medium.

3-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

The interaction of follicular cells and steroidogenic activity of the ovary.

Investigations of ovarian cell types with the help of the tissue culture technique were presented. The importance of cell-to-cell communication and the interaction of the two cell types in producing steroid hormones by the ovary were discussed. Special attention was paid to the influence of prolactin on particular ovarian tissues. New concepts of the regulation of corpus luteum function were described.

Animals↗