• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.399-402
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• 2012

Bufalin is a traditional oriental medicines which induces apoptosis in some lines of human tumor cells. It constitutes the major digoxin-like immunoreactive component of Chan Su, obtained from the skin and parotid venom glands of toads. Bufalin is cardioactive C-24 steroids that exhibits a variety of biological activities, such as cardiotonic, anaesthetic, blood pressure stimulatory, respiratory and antineoplastic effects. In terms of its anti-tumor activity, bufalin has been demonstrated to inhibit the growth of tumors, such as endometrial and ovarian cancers. This commentary introduces biologic and therapeutic effects of bufalin in treating some cancers. The compound is able to mediate inhibition of cell growth, cell cycle arrest, apoptosis, and expression of genes related to the malignant phenotype in human cancer cells.

• Advances in Traditional Medicine
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• v.4 no.2
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• pp.77-81
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• 2004

Petroleum ether, benzene and alcohol extracts of seeds of C. juncea administered orally at the dose level of 25mg/100g body weight to adult female mice for 30 days, resulted in irregular estrous cycle with prolonged estrus and metaestrus and reduced diestrus and proestrus during the experimental period. Histological studies of the ovary indicate increases in the number of atretic follicles but decreases in the number of developing follicles, Graafian follicles and corpora lutea. The total cholesterol content of the ovary is increased, whereas ascorbic acid content is decreased. The weight of the uterus and its micrometric measurement in all experimental mice are increased significantly. The alcoholic extracts showed estrogenic activity in immature mice by early opening of the vagina, premature cornification of the vaginal epithilium and increases in uterine weight. However, alcohol extract of seeds of C. juncea was more effective in causing these changes compared to other extracts. After subjecting to preliminary phytochemical screenings alcohol extract showed positive; test for alkaloids, steroids, glycosides, flavones, phenols and tannins.

• The Korean Journal of Zoology
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• v.19 no.1
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• pp.7-14
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• 1976

The release of ovulatory level of LH from the pituitary gland occurred between 51 and 56 hours after PMS treatment in 24-day old female rats. Estradiol given simultaneously with PMS advanced LH release 24 hours. Injections of estradiol $(2.5\\sim 40\\mu g)$ at 0, 24 and 48 hours failed to increase pituitary LH level by 51 hours after the first injection in ovariectomized rats. However, $5 \\mu g$ estradiol at 0, 24 and 48 hours followed by 1 mg progesterone at 48 hours elevated pituitary L level by 51 hours in ovariectomized rats. These results indicate that advancement of PMS-induced ovulation by estradiol in the previous study occurred by means of inducing premature release of LH and estrogen might synergize with progesterone in the regulation of LH in the pituitary gland.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.57-75
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• 1987

Two modalities of gonadotropin secretion, pulsatile gonadotropin and preovulatory gonadotropin surge, have been identified in the mammals. Pulsatile gonadotropin secretion is modulated by the pulsatile pattern of GnRH release and complex ovarian steroid feedback actions. The neural mechansim that regulates the pulsatile release of GnRH in the hypothalamus is called "GnRH pulse generator". Ovarian steroids, estradiol and progesterone, appear to exert thier feedback effects both directly on the pituitary to modulate gonadotropin release and on a hypothalamic site to modulate GnRH release; estradiol primarily affects the amplitude while progesterone decreases the frequency of the pulsatile GnRH. Steroid hormones are known to affect catecholamine transmission in brain. MBH-POA is richly innervated by NE systems and close apposition of NE terminals and GnRH cell bodies occurs in the MBH as well as in the POA. NE normally facilitates pulsatile LH release by acting through ${\alpha}-receptor$ mechanism. However, precise nature of facilitative role of NE transmission in maintaining pulsatile LH has not been clearly understood. Close apposition of DA and GnRH terminals in ME might permit DA to influence GnRH release. Action of DA transmission probably is mediated by axo-axonic contacts between GnRH and DA fibers in the ME. Dopamine transmission does not normally regulate pulsatile LH release, but under certain conditions, increased DA transmission inhibit LH pulse. Endogenous opioid acts to suppress the secretion of GnRH into hypophysial portal circulation, thereby inhibiting gonadotropin secretion. However, an interaction between endogenenous opioid peptides and gonadotropin release is a complex one which involves ovarian hormones as well. LH secretion appears to be most suppressed by endogenenous opioids during the luteal phase, at a time of elevated progesterone secretion. The arcuate nucleus contains not only cell bodies for GnRH and ${\beta}-endorphin$ but also a dense aborization of fibers suggesting that GnRH release is changed by the interactions between GnRH and ${\beta}-endorphin$ cell bodies within the arcuate nucleus. The frequency and amplitude of pulsatile LH release seem to be increased during the preovulatory gonadotropin surge. Estradiol exerts positive feedback action on the hypothalamo-pituitary axis to trigger preovulatory LH surge. GnRH is also crucial hormonal stimulus for preovulatory LH surge. It is unlikely, however, that increased secretion of GnRH during the preovulatory gonadotropin surge represents an obligatory neural signal for generation of the LH discharge in primates including human. Modulation of preovulatory LH surge by catecholamines has been studied almost exclusively in rats. NE and E may be involved in distinct way to accumulate GnRH in the MBH and its release into the hypophysial portal system during the critical period for LH surge on proestrus in rats. However, the mechanisms whereby augmented adrenergic transmission may facilitate the formation and accumulation of GnRH in the ME-ARC nerve terminals before the LH surge have not been clearly understood.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.281-289
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• 1989

The present study was disigned to determine the concentration of bioavailable steroid hormones in the atretic follicular fluid (FF). The concentradons of progesterone (P), testosterone (T), estradiol (E), androstenedione (A), and 5-$\alpha$ dihydrotestosterone (DIlT) were determined by the established methods of luminescent immunoassay (LIA) or radioimmunoassay (RIA). Concentrations of T, A and Diff in human FF from smail (< 6 mm). medium (8-15 mm), and large (> 15 mm) atretic follicles were significandy higher than those of normal ones (p < 0.01). However, the levels of T, A and DHT in smail atretic foflicle were significandy lower than those found in normal one. The concentrations of P in atretic FF from porcine small (< 3 mm), medium (4-6 mm), and large (> 7 mm) follicles were not different from that of normal ones. However, the concentration of E in atretic forncles of each group was significantly lower than that of normal group (p < 0.001 in each group). On the other hand, the percentages of bioavailable T (BI) in human FF were significandy (p <0.001) higher than those in normal groups. The BT in normal or atretic FF was more than 90 % of total T. The present result demonstrates that the bioavailable androgen, but not E levels in atretic follicles is higher than that of normal one, and that the atretic mechanism might be dependent on the ovarian forncle size in the developmental stage and on the animal model system. Moreover, the present study suggests that the steroids found in the FF are the bioavailable forms and the concentration of BT in FF could be used as one of the valuable criteria classifying the ovarian atretic follicle.

• Journal of Aquaculture
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• v.11 no.1
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• pp.119-124
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• 1998

The relative effectiveness of C21-steroids and human chorionic gonadotropin(HCG) on maturation and ovulatin was investigated in vitro using the isolated oocytes or ovarian fragments from the sea bass, Lateolabrax japonicus. ${\alpha}$-hydroxy, 20${\beta}$-dihydroprogesterone(17${\alpha}$20${\beta}$OHP : 5, 50, 500, 1000ng/ml), 17${\alpha}$-hydroxy, 20${\alpha}$-dihydroprogesterone(17${\alpha}$20${\alpha}$OHP : 5, 50, 500, 1000ng/ml) and HCG (5, 50, 500IU/ml) were effective in inducing oocyte maturation, GVM (germinal vesicle migration) or GVBD(germinal vesicle breakdown), compared to control except 17${\alpha}$20${\beta}$OHP and 17${\alpha}$20${\alpha}$OHP at 5ng/ml. 17${\alpha}$20${\beta}$OHP showed the greatest effect on oocyte maturation at 50ng/ml. A combination of 17${\alpha}$20${\beta}$OHP(50ng/ml) and HCG(500IU/ml) led to a significant increase (p<0.05) in GVBD when compared with 17${\alpha}$20${\beta}$OHP or HCG alone. These findings suggest that the two in combination acts synergistically to induce GVBD. 17${\alpha}$20${\beta}$OHP (1~1000ng/ml) and HCG(1~500IU/ml) also induced ovulation in ovarian fragments at all concentrations used ; more effective at lower concentrations(1~50ng/ml or IU/ml). It was shown that HCG was more potent in inducting ovulatin than 17${\alpha}$20${\beta}$OHP.

• Development and Reproduction
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• v.10 no.4
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• pp.247-254
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• 2006

It is well publicized that the existence of various endocrine disrupting chemicals threatens normal sexual development of many sedentary marine fishes in the coastal areas. However, a suitable marine fish species for efficient monitoring of this threatening has yet to be identified. One of the difficulties in estimating the effect of endocrine disruption in marine fish is the absence of clear distinction between testicular and ovarian structures at the early stages of sex differentiation. In search of a potential test species, we have investigated the microscopic structures of sexually undifferentiated and differentiated gonads and the susceptibility of gonadal differentiation to exogenous sex steroids during the sex differentiation period in a sedentary marine rockfish, Sebastes schlegeli. Male gonads in this species contained dark pigmentation that made them distinct from female gonads. Treatment either with $estradiol-17\;{\beta}(E_2)$ or $17\;{\alpha}-methyltestosterone$ (MT) significantly altered the sex ratios with the complete sex changes or the occurrence of ovotestis that was easily identified by the mixed structure of dimorphic gonads (coexistence of ovarian cavity/primary oocytes and dark pigmentation/seminiferous tubules). Results in this study suggest that S. schlegeli can be developed as a monitoring/test fish species for endocrine disruption in marine fish in the coastal areas.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.119-130
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• 1989

본 연구는 생식주기중 폐쇄여포액내에서 생물학적， 면역학적 특성을 나타내는 GTH 의 변화를 조사하고 steroid hormone과의 상관관계를 조사하며 국부조절인자로서 의 GTH의 역 활을 조사하고자 하였다. 가임기간중 215개의 여포와 IVF과정에서 185개의 여포를 얻어 여포액내 GTH의 생물학적 또는 면역학적 활성을 측정하였다. Bioactive LH(bLH)는 생쥐의 Leydig cell-testosterone production assay, bFSH는 흰쥐의 Sertoli cell aromatase assay로 측정 하였 다. Immunological GTH(iLH , iFSH) 는 MaiaClone RIA , Delfia kits를 사용하였다. 여포액내 iLH, iFSH , ihCG 는 hyperstimulation에 의해 형성된 여포의 크기와는 무관하였다. 또 hMG, huFSH 의 처리와도 상관성이 없었다. T의 농도가 높은 여포액내의 iFSH는 현저히 낮았으며 E, P 가 고농도인 여포의 ihCG 양은 현저히 낮았다. 과배란이 유도된 난소의 여포액내 iLH는 LH specific RIA로 측정시 3mIU/ml 이하이었다. 생식주기중 여포액내 bLH, bFSH는 배란기에 현저히 증가 하였다. 혈청내 GTH B/I ratio는 엘정한 반면 여포액내 LH，FSH의 생물학적， 면역학적 활성은 미수정란을 가지거나 폐쇄된 여포내의 활성보다 현저하게 높았다. 위의 결과로 보아 여포액내 생식소자극호르온은 면역학적활성보다 높은 생물학적 활성을 가지며， 생리적 현상의 지표가 된다고 추론된다. 또한 steroid, bGTH는 여포의 선택， 폐쇄를 구분하는 지표로 사용가능하며， 여포가 폐쇄될때 여포액내 B/I ratio가 현저히 낮아지는 것으로 보아 GTH의 활성이 감소되는 것으로 판단된다.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.273-281
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• 1996

Previously, we have proposed a two-cell type model for follicular steroidogenesis inamphibians with Rana nigromacu lota. Present experiments were carried out to ascertain whether the model Is applicable to R. dybowskii. The role of theca layer were also reassessed by using granulosa cell-free pure theca layer (P-THEP). Theca/epithelium (THEP) layers, P-THEP layers, and granulosa cell enclosed-oocytes () were obtained from ovarian follicles of R. dybowskii by microdissection. Intact follicles (IFs) and different types of tissues were cultured for 6 hour in amphibian Ringer's m the presence or absence of FPII (0.05 gland/mi) or various steroid precursor (100 ng/ml). The amounts of product steroids converted by the components were measured by RIA. Exogenously added pregnenolone (P5) resulted in a marked increase in progesterone (P$_4$) by GCEOs (2143 pg/follicle) and IFs (2346 pg/follicle) but a smaller increase in P4 by THEP layer (495 pg/follicle). Addition of P$_4$ increased 17 a-hydroxyprogesterone (17 $\alpha$-OHP$_4$) levels by GCEOs (1118 pg/follicle) and IFs (1333 pg/follicle) but less by THEP layer (290 pg/follicle). However, much less amounts of P$_4$ or 17 $\alpha$-OHP$_4$ were producad by P-THEP layers than THEP in the presence of P5. Exogenous 1 7$\alpha$-OIIP$_4$ increased androstenedione (AD) levels by GCEOs (1415 pg/follicle) and IFs (561 pg/follicle) but not by THEP layers. In contrast, addition of AD resulted m a marked increase in testosterone (T) levels by TIIEP (2594 pg/follicle) and IFs (2223 pg/follide) but much less by GCEOs (339 pg/follicle). Exogenous T increased estradiol (E$_2$) levels by GCEOs (551pg/follicle) and IFs (887 pg/follicle), but not by THEP layer (<10 pg/follicle). Without addition of FPH or steroid precursors, very low or nondetectable levels of steroids were produced (< 20 pg/follicle) by all the types of follicular components examined. The data presented here indicate that the two-cell type model based on the study with R. nigromacu Iota is applicable to R. dybowskii and also suggest that the minor pathway, which convert P5 to 17$\alpha$-OHP$_4$, is not present in theca layer.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.19-28
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• 1994

The effects of gonadoropin-releasing hormone (GnRH) and ovarian steroid hormones on the release of luteinizing hormone (LH) and its subunit mRNA levels were investigated in anterior pituitary cells in culture. LH concentration was measured by a specific radioimmunoassay and mRNA levels of u and $LH{\beta}$ subunits by RNA slot blot hybridization assay. GnRH stimulated LH release in a dose-dependent manner from cultured pituitary cells. However, the basal LH release in the absence of GnRH was not changed during the course of 24h culture, strongly suggesting that release of LH is directly controlled by GnRH. The treatment of the pituitary cells with GnRH increased $LH{\beta}$ subunit mRNA levels in a dose-dependent manner, reaching the maximum with $2\;{\times}\;10^{-10}M$ GnRH while no significant increase in ${\alpha}$ subunit mRNA levels was observed after GnRH treatment. Estradiol did not augment GnRH-induced LH release while progesterone augmented GnRH-induced LH release in a dose-dependent manner at the level of pituitary. However, estradiol and progesterone increased basal and GnRH-induced $LH{\beta}$ subunit mRNA levels in a dose-dependent manner. The treatment of estrogen antagonist, LYI17018 blocked the effect of estradiol on GnRH-induced $LH{\beta}$ subunit mRNA levels in a dose-dependent manner while progesterone antagonist, Ru486 tended to block the effect of progesterone on GnRH-induced $LH{\beta}$ subunit mRNA levels. It is therefore suggested that GnRH Playa a major role in LH release and subunit biosynthesis by influencing the steady state $LH{\beta}$ subunit mRNA loves and ovarian steroid hormones modulate subunit biosynthesis via directly acting on pituitary gonadotropes.