• Animal cells and systems
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2007

Recently, we have shown that some endocrine disruptors, heavy metals, organotins and azoles suppressed steroidogenic enzymes such as P450 side-chain cleavage enzyme (P450scc) and aromatase in bullfrog ovarian follicles. In the present study, by using an amphibian ovarian follicle culture system, we examined the effects of these endocrine disruptors on maturation and ovulation of oocytes from Rana dybowskii in vitro. Ovarian fragments or isolated follicles were cultured for 24 h in a medium containing frog pituitary homogenate (FPH) or progesterone ($P_{4}$) with or without endocrine disruptors, and oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation were examined. Among the organotins, tributyltin (TBT) strongly inhibited both FPH-and $P_{4}-induced$ oocyte maturation ($ED_{50}$:0.6 and 0.7 ${\mu}M$, respectively); however, tetrabutyltin (TTBT) and dibutyltin (DBT) showed only partial suppression, while monobutyltin (MBT) showed no inhibitory effect. All of the organotins suppressed $P_{4}-induced$ oocyte ovulation very effectively at a low concentration, and TBT and DBT exerted an inhibitory effect on FPH-induced ovulation. Among the heavy metals, mercury (Hg), cadmium (Cd) and cobalt (Co) were very effective in inhibiting FPH-induced oocyte maturation and ovulation, while lead (Pb), arsenite (As) and zinc (Zn) were less effective. However, all of the heavy metals suppressed FPH-induced oocyte ovulation at a high dose ($100{\mu}M$). Among the azoles, itraconazole (ICZ), ketoconazole (KCZ) and clotrimazole (CTZ) effectively inhibited FPH-induced oocyte maturation and ovulation, while econazole (ECZ), miconazole (MCZ) and fluconazole (FCZ) were considerably less effective. These results demonstrated that the abovementioned endocrine disruptors exhibited differential effects on oocyte maturation and ovulation in amphibian follicles and that the frog ovarian culture system could be used as an effective experimental tool to screen and evaluate the toxicity of various endocrine disruptors in vitro.

• The Korean Journal of Zoology
• /
• v.33 no.1
• /
• pp.53-62
• /
• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Animal cells and systems
• /
• v.2 no.1
• /
• pp.87-91
• /
• 1998

The present study investigated the involvement of the phospholipase C (PLC) and protein kinase C (PKC) signaling pathways during progesteroneinduced meiotic maturation in amphibian (Rana dybowskii) oocytes. Prosesterone-induced germinal vesicle breakdown (GVBD) of oocytes was significantly inhibited by a PKC inhibitor, staurosporine and a PLC inhibitor, U73122, in a dose-dependent manner. In contrast, U73343, an inactive analogue of U73122, was ineffective in suppressing GVBD. PKC activity in oocytes reached a maximum level at 30 min after progesterone stimulation and this elevated PKC activity was effectively suppressed by U73122 or staurosporine, suggesting that the activation of PKC enzyme is closely linked to PLC signaling during oocyte maturation. In addition, these inhib itors blocked the maturation promoting factor (MPF) activity which appeared in oocytes in response to progesterone, suggesting that PKC activation is an important signal for MPF activity. Therefore, this study demonstrates that the activation of PKC via PLC signaling is directly linked to an intracellular protein kinase cascade related to the appearance of MPF activity during meiotic maturation in amphibian (Rana dybowskii) oocytes.

• Journal of dental hygiene science
• /
• v.21 no.4
• /
• pp.219-226
• /
• 2021

Background: Proper detection and management of dental plaque are essential for individual oral health. We aimed to evaluate the maturation level of dental plaque using a two-tone disclosing agent and to compare it with the fluorescence of dental plaque on the quantitative light-induced fluorescence (QLF) image to obtain primary data for the development of a new dental plaque scoring system. Methods: Twenty-eight subjects who consented to participate after understanding the purpose of the study were screened. The images of the anterior teeth were obtained using the QLF device. Subsequently, dental plaque was stained with a two-tone disclosing solution and a photograph was obtained with a digital single-lens reflex (DSLR) camera. The staining scores were assigned as follows: 0 for no staining, 1 for pink staining, and 2 for blue staining. The marked points on the DSLR images were selected for RGB color analysis. The relationship between dental plaque maturation and the red/green (R/G) ratio was evaluated using Spearman's rank correlation. Additionally, different red fluorescence values according to dental plaque accumulation were assessed using one-way analysis of variance followed by Scheffe's post-hoc test to identify statistically significant differences between the groups. Results: A comparison of the intensity of red fluorescence according to the maturation of the two-tone stained dental plaque confirmed that R/G ratio was higher in the QLF images with dental plaque maturation (p<0.001). Correlation analysis between the stained dental plaque and the red fluorescence intensity in the QLF image confirmed an excellent positive correlation (p<0.001). Conclusion: A new plaque scoring system can be developed based on the results of the present study. In addition, these study results may also help in dental plaque management in the clinical setting.

• The Korean Journal of Zoology
• /
• v.34 no.2
• /
• pp.188-195
• /
• 1991

The effect of lanthanum ion (La3 +), which is associated with the mobilization of internal calcium, on the regulation of oocyte maturation was investigated with Rana dybowskii follicles. Follicular oocytes matured (germinal vesicle breakdown, GVBD) dose dependently when they were exposed to La3+ (O.O1-1.O mM) and the maturation occurred in 9-12 hours after the la3+(0.33 mM) stimulation. lanthanum also accelerated the onset of maturation of the lollicular oocytes exhibiting spontaneous maturation. Three hours of exposure to La3+ was enough to induce the maturation. The La3 + -induced maturation was not associated with progesterone production by follicle cells, and the maturation was inhibited by forskolin (9 $\mu$ M), and cyclobeximide (0.01 - 1.0 - $\mu$g/2 ml) in the medium. The La3+ and hormone stimulated maturation showed the same patterns of protein phosphorylation and dephosphorylation during the maturation. The data suggest that the oocyte maturation by La3+ stimulation is very similar to that by progesterone. Thus, it seems that internal mobilization of Ca2+ plays a key role in the initiation of oocyte maturation in amphibia.

• Clinical and Experimental Reproductive Medicine
• /
• v.13 no.2
• /
• pp.201-206
• /
• 1986

These experiments were conducted to know whether RNA syntheis is involved in the cumulus expansion and oocyte maturation of mouse cumulus-oocyte complexes in vitro. Mouse cumulus-oocyte complexes(COC's) were cultured in the presence of cordycepin, an inhibitior of RNA synthesis and its effect on the cumulus expansion and oocyte maturation were examined. The results were as follows. 1. Continuous presence of cordycepin in the medium(200${\mu}g/ml$) inhibited the HCG-induced cumulus cell expansion of mouse complexes. This inhibition was reversible. 2. When the COC'S were preincubated with different concentration of cordycepin plus HCG for 3 hours and then transferred to the plain medium, the HCG induced cumulus expansion was suppressed at $100{\mu}g/ml$ of cordycepin. 3. When the COC'S were cultured with cordycepin after HCG stimulation(3hrs), the cumulus expansion were not suppressed by cordycepin. 4. Oocyte meiotic maturation did not appear to be affected by cordycepin. The data presented here imply that RNA synthesis is involved in the cumulus expansion process and that mouse oocytes are more resistant to RNA synthesis inhibitor than cumulus cells.

• Clinical and Experimental Reproductive Medicine
• /
• v.13 no.2
• /
• pp.195-200
• /
• 1986

In order to know when the cumulus cells of mouse follicles get ability to expand in vitro, the oocyte cumulus complexes obtained from different growing ages of mice were cultured in the medium containing HCG and their rate of expansion were observed and at the same time their maturation rate was examined. The growth of follicles was also checked by histological method. It was impossible to isolate the oocyte-cumulus complexes from 13 or 15 days old mouse ovaries. The oocyte-cumulus complexes collected from 17 days old mouse were partially induced to expanded by HCG, and from 19 days, most of the complexes were induced to full expansion. The rate of cumulus cell expansion by HCG and the oocyte maturation increased steadly during the growing ages to adult. Thus, the time for follicles to get competence for expansion and maturation seems to be closely related. Antral follicles were appeared from 17 days old mice and Graafian follicles were seen from 21 days old mice. The competence for cumulus expansion increased during follicle growth up to 21 days old mice.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.7
• /
• pp.972-979
• /
• 2008

It has been recently shown that expression of the LH receptor (LHR) in cumulus cells is related with FSH-induced meiotic resumption of mouse cumulus enclosed oocytes (CEOs). However, to date, it is still unclear whether LHR expression in cumulus cells plays a key role during FSH-induced oocyte maturation. The purpose of this study was to characterize the functional role of LHRs in cumulus cells. CEOs were isolated from eCG-primed preovulatory follicles and cultured in hypoxanthine (HX) arrested medium. LHR protein expression in cumulus cells was time-dependent increasing during the process of FSH-induced oocyte maturation. While the sense oligodeoxynucleotide (ODN) had no effect, antisense ODN inhibited FSH-induced LHR expression and meiotic resumption. Moreover, this antisense ODN against LHR could inhibit FSH-induced mitogen-activated protein kinase (MAPK) phosphorylation. This study suggested that LHR expression in cumulus cells is involved in FSH-induced oocyte meiotic resumption, which process is possibly regulated by MAPK cascade.

• Korean Journal of Organic Agriculture
• /
• v.9 no.1
• /
• pp.17-27
• /
• 2001

To clarify the proper and safe duration of maturation periods for sawdust-pig manure composts, leaf lettuces were applied with pig manure composts fermented for 15, 30, 45, 60, 75 days and 1 year (control) and cultivated in a plastic house with or without additional PE film tunnel. The changes in physiochemical properties of soil and leaf lettuce growth were measured. Shorter duration of maturation periods enhanced the generation of N $H_3$ gas from the composts and resulted in significant decrease in seed germination, growth and yield of leaf lettuce. Under with and without PE tunnel conditions the concentration of N $H_3$ from compost over 3.8 and 2.1 mg/100g composts, respectively induced growth reduction. In proportion to the increase of maturation duration saw-dust containing pig manure exhibited decrease in C/N ratio, N $H_4^{+}$-N, N $H_4^{+}$N $O_3^{-}$ ratio but increase in N $O_3^{-}$-N contents. In case of applying pig manure compost without PE film tunnel condition the minimum maturation period of pig manure composts for safe leaf growth was 60 days, while minimum 75 days of maturation was required when applied with PE film tunnel. tunnel.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.23 no.3
• /
• pp.14-25
• /
• 2010

Purpose: The purpose of this study is to investigate inhibitory effect on the maturation of dendritic cells from aqueous extract from Nardostachys Jatamansi(NJ). Methods: I examined the phenotypic maturation(class II MHC, CD40, CD86), expression of pro-inflammatory cytokine(TNF-$\alpha$, IL-6, IL-12) and endocytosis of FITC-Dextran in the LPS-induced bone marrow-derived dendritic cells(BMDCs) of mice. Furthermore, the Western-blot analysis reveals the mechanism of inhibitory effect. Results: 1. The NJ extract inhibited the phenotypic maturation of BMDCs in a dose-dependent manner. 2. The NJ extract inhibited the LPS induced cytokine production of BMDCs in a dose-dependent manner. 3. The NJ extract enhanced the endocytosis of Dex-FITC in LPS treated DC. 4. The NJ extract inhibited the activation of JNK and p38 phosphorylation, but not ERK phosphorylation of MAPK family and doesn't inhibit Ik-Ba degradation in LPS-stimulated BMDCs. Conclusion: These results suggest that NJ extract is able to attenuate the inflammation and maturation in BMDCs and may inhibit proliferation of T cells. In conclusion, this experiment suggests that NJ extract may be useful in hypersensitivity disease including autoimmune disease.